Related Terms

• Ascorbic acid, B vitamins, B-complex vitamins, biotin, calcium, cholecalciferol, chromium, cobalamin, copper, cyanocobalamin, fat-soluble vitamins, folate, folic acid, iodine, iron, magnesium, manganese, molybdenum, multiple vitamin-mineral, MVI, MVM, niacin, pantothenic acid, phylloquinone, pyridoxine, retinol, riboflavin, selenium, thiamin, tocopherol, vitamin A, vitamin B1, vitamin B2, vitamin B3, vitamin B5, vitamin B6, vitamin B12, vitamin C, vitamin D, vitamin E, vitamin H, vitamin K, vitamins, water-soluble vitamins, zinc.

Background

• Vitamins and minerals are essential nutrients that the body needs to grow, develop, and function normally. With few exceptions, vitamins cannot be made by the human body and must be obtained from food or dietary supplements. Also, in humans, vitamin D is made by the skin when exposed to sunlight. Minerals cannot be made by the human body and must be obtained from food or supplements. A well-balanced diet typically provides all of the vitamins and minerals the body needs.

• Multivitamins are manufactured supplements that may contain a wide range of vitamins and minerals. Multivitamins are meant to provide individuals with the proper amounts and types of vitamin and mineral nutrients that the body needs. Supplemental multivitamins may benefit individuals who do not get enough vitamins and minerals from food, as well as people who have difficulty absorbing nutrients from food.

• Fortified foods are also a source of some vitamins and minerals. These foods, including milk and some ready-to-eat cereals, contain added vitamins and minerals.

• There are 13 essential vitamins that the body needs: vitamins A, C, D, E, K, and the B vitamins (folate, thiamin, riboflavin, niacin, pantothenic acid, biotin, vitamin B6, and vitamin B12). Vitamins perform a wide variety of functions in the body. For instance, vitamin C is necessary to form collagen in bones, cartilage, muscle, and blood vessels, and it helps the body absorb iron. Some vitamins, such as vitamins A and E, are antioxidants. Antioxidants are molecules that work to prevent damage that occurs in cells and body tissues due to both normal bodily processes and exposure to some chemicals. Antioxidants may work by preventing or slowing the oxidation of DNA and proteins.

• Vitamins may be classified as fat-soluble or water-soluble. The fat-soluble vitamins are vitamin A (retinol), vitamin D (cholecalciferol), vitamin E (tocopherol), and vitamin K (phylloquinone; vitamin K1). Fat-soluble vitamins dissolve in oily substances such as olive oil and do not dissolve in water. Fat-soluble vitamins that the body does not use immediately are stored in body fat and in the liver. The body removes fat-soluble vitamins from these storage sites and uses them as needed. Because they may be available from storage, fat-soluble vitamins do not have to be supplied in the diet on a daily basis. Bile acids are needed for absorption of fat-soluble vitamins. Bile acids are a component of bile, a complex liquid that helps the body absorb fat. Bile is made by the liver and stored in the gall bladder. It has been hypothesized that eating hard-to-digest fats or oils may lead to deficiencies of fat-soluble vitamins. More research is needed to investigate this claim. Consuming excessive amounts of fat-soluble vitamins may be toxic, because excessive amounts are then stored in fat and the liver.

• The water-soluble vitamins are biotin (vitamin H; vitamin B7), vitamin B1 (thiamin), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B9 (folate), vitamin B12 (cobalamin, cyanocobalamin), and vitamin C (ascorbic acid). Water-soluble vitamins dissolve in water and are easily absorbed by the body. When a person ingests a water-soluble vitamin, the body uses what it needs immediately. Any unused vitamin is excreted in the urine or, for some water-soluble vitamins, in the feces. For this reason, water-soluble vitamins need to be consumed regularly so the body has a steady supply. The body does not store large amounts of water-soluble vitamins. Therefore, water-soluble vitamins are less likely to cause toxicity than fat-soluble vitamins.

• Not everyone requires the same amount of each vitamin and mineral. The recommended daily dose varies depending on a person's age, gender, overall health, environment, and eating habits. For instance, when a woman becomes pregnant, her body requires 50% more iron to support the growing fetus. Daily folate requirements also increase by 50% in pregnant women. Adequate folate intake in women who may become pregnant is important for reducing the risk of birth defects of the brain and spinal cord known as neural tube defects.

• The U.S. government has compiled a series of guidelines on recommended daily dosages of essential vitamins and minerals. The Institute of Medicine of the National Academy of Sciences has developed a series of Dietary Reference Intakes (DRIs) for vitamins and minerals. The four components of the DRIs are the Recommended Dietary Allowances (RDAs), Adequate Intakes (AIs), Tolerable Upper Intake Level (ULs), and Estimated Average Requirements (EAR). The RDA is the amount of a nutrient that is sufficient for 97-98% of healthy individuals. When an RDA cannot be determined, an AI value is computed based on how much of the nutrient is consumed by a group of healthy people. The UL is the maximum daily amount of a nutrient that a person may consume without side effects. The EAR refers to the amount of a nutrient that is sufficient for an estimated 50% of healthy individuals in a population.

• The kinds and amounts of nutrients in multivitamins vary widely. A typical multivitamin and mineral supplement may include some or all of the following: vitamins A, C, D, E, and K; biotin; B vitamins (thiamin, riboflavin, niacin, pantothenic acid, vitamin B6, and vitamin B12); folic acid; and the minerals calcium, chromium, copper, iodine, iron, magnesium, manganese, molybdenum, selenium, and zinc.

• Doctors often recommended multivitamins to individuals who eat poor diets or have difficulty absorbing nutrients. For example, multivitamins are usually recommended for people over 60 years old because as the body ages, it becomes more difficult to absorb certain vitamins. However, experts disagree on whether multivitamins are necessary for people who eat healthy and well-balanced diets.

Diet

• Fat-soluble vitamins:

• General: The fat-soluble vitamins are vitamin A (retinol), vitamin D (cholecalciferol), vitamin E (tocopherol), and vitamin K (phylloquinone; vitamin K1).

• Vitamin A (retinol): Vitamin A is needed for vision. It also helps the body maintain healthy skin and mucous membranes. It is important for immunity, tissue repair, bone growth, and embryo development. It also has antioxidant effects.

• Food and drink sources: Apricots, beef, cantaloupe, carrots, cheese, chicken, dark leafy vegetables (such as kale and spinach), liver, mango, milk, oatmeal, papaya, peaches, peas, peppers, pumpkin, sweet potatoes, tomatoes, and yellow squashes. The common forms of vitamin A found in plant sources are vitamin A precursor molecules called carotenoids. Beta-carotene, also known as provitamin A, is a carotenoid that is converted into vitamin A by the human body.

• Recommended Dietary Allowance (RDA): The RDA is 900 micrograms for adult men and 700 micrograms for adult women. For pregnant women aged 19 years and older, 770 micrograms daily is recommended. For lactating women aged 19 years and older, 1,300 micrograms daily is recommended.

• Symptoms of deficiency: Acne, dry hair, fatigue, growth impairment, insomnia, hyperkeratosis (thickening and roughness of skin), immune impairment, night blindness, and weight loss have been reported.

• Side effects of high oral doses: Excessive doses may cause nausea, vomiting, headache, blurred vision, dizziness, liver problems, birth defects, and clumsiness. Vitamin A may also increase a person's risk of developing osteoporosis. People who do not eat enough protein, drink high amounts of alcohol, or have liver problems or high cholesterol may have an increased risk of experiencing these side effects. Also note that the provitamin A carotenoids, such as beta-carotene, are less toxic than the retinol form of vitamin A, because the body slows conversion of provitamin A into vitamin A when there is enough stored vitamin A. Yellow skin discoloration is the most prominent side effect of excess provitamin A carotenoids.

• Vitamin D (cholecalciferol): Vitamin D helps the body absorb the minerals calcium and phosphorus. It is important for immune system function, and it helps prevent rickets and osteomalacia (abnormal bone softening). Vitamin D may also help prevent bone fractures resulting from osteoporosis.

• Food and drink sources: Beef, cheese, cod liver oil, egg, fortified breakfast cereal, fortified dairy products, liver, mackerel, margarine, milk, salmon, sardines, and tuna. Vitamin D is also made by the body after exposure to sufficient amounts of sunlight.

• Adequate Intakes (AI): For all individuals (males, female, pregnant/lactating women) under the age of 50 years, 5 micrograms (200 international units (IU)) is recommended.For all individuals 50-70 years old, 10 micrograms daily (400 IU) is recommended. For those who are over 70 years old, 15 micrograms daily (600 IU) is suggested. Some authors have questioned whether the current recommended adequate levels are sufficient to meet physiological needs, particularly for individuals deprived of regular sun exposure. The upper limit (UL) for vitamin D has been recommended as 2,000 IU daily, due to toxicities that may occur when taken in higher doses.

• Symptoms of deficiency: Burning sensation in the mouth, diarrhea, insomnia, blurred vision, nervousness, osteomalacia (abnormal bone softening), osteoporosis, rickets, and scalp sweating have been reported.

• Side effects of high oral doses: Excessive doses of vitamin D may cause nausea, vomiting, decreased appetite and weight loss, constipation, confusion, irregular heartbeat, and hypercalcemia (elevated levels of calcium in the blood). Symptoms of vitamin D toxicity may include bone loss, formation of calcium deposits in the kidneys and heart, and calcium and phosphate deposits in the soft tissues.

• Vitamin E (tocopherol): Vitamin E is important for healthy blood flow. It helps repair body tissues and acts as an antioxidant.

• Food and drink sources: Almonds, broccoli, corn oil, green leafy vegetables, kiwi, mango, margarine, nuts, safflower oil, soybean oil, spinach, sunflower oil, sunflower seeds, vegetable oil, and wheat germ.

• Recommended Dietary Allowance (RDA):The RDA for males and females older than 14 years and pregnant women of any age is 15 milligrams (22.5 international units (IU)); for breastfeeding women of any age, 19 milligrams (28.5 IU).

• Symptoms of deficiency: Neurological problems (such as gait disturbances and poor reflexes) and shortened red blood cell life have been reported.

• Side effects of high oral doses: Recent evidence suggests long-term supplementation with high doses of vitamin E may slightly increase the risk of death (from "all causes"). These conclusions have been criticized by some experts because they are based on recalculations (meta-analyses) of the results of smaller studies, often of patients with chronic illnesses. Study quality was mixed, and results were variable. Chronic vitamin E supplementation should be used cautiously, and high-dose vitamin E should be avoided. Acute overdose of vitamin E is uncommon.People who take blood thinners, such as warfarin (Coumadin®), should consult their healthcare providers before taking vitamin E supplements.

• Vitamin K (phylloquinone; vitamin K1): Vitamin K is necessary for normal blood clotting and bone formation in humans.

• Food and drink sources: Broccoli, brussels sprouts, cabbage, canola oil, green leafy vegetables (such as collard greens, kale, Swiss chard, and mustard greens), parsley, soybean oil, spinach, and turnip greens.

• Recommended Dietary Allowance (RDA): The RDA for adult men is 120 micrograms, and the RDA for adult women is 90 micrograms.

• Symptoms of deficiency: Heavy menstrual bleeding, gastrointestinal bleeding (stomach and intestinal bleeding), hematuria (blood in the urine), nosebleeds, bleeding gums, and easy bruising have been reported.

• Side effects of high oral doses: Reports of significant vitamin K toxicity are lacking. People with bleeding disorders or those taking blood thinners, such as warfarin (Coumadin®), should consult their healthcare providers before taking vitamin K supplements.

• Water-soluble vitamins:

• General: The water-soluble vitamins are: biotin (vitamin H; vitamin B7), vitamin B1 (thiamin), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B12 (cobalamin, cyanocobalamin), vitamin C (ascorbic acid), and folate (vitamin B9).

• Biotin (vitamin H): Biotin helps the body use nutrients. It helps maintain the nervous system, and it is needed to make red blood cells.

• Food and drink sources: Eggs, fresh vegetables, kidney, liver, and rolled oats.

• Recommended Dietary Allowance (RDA): The RDA for adult men and women is 30 micrograms.

• Symptoms of deficiency: Dermatitis (inflammation of the skin), eye swelling, hair loss, decreased muscle control, insomnia, and muscle weakness have been reported.

• Side effects of high oral doses: Reports of significant biotin toxicity are lacking.

• Folate and folic acid: Folate is the naturally occurring form of this vitamin and is found in food. Folic acid is the man-made form of this vitamin. Folate or folic acid is needed for the synthesis of DNA, the genetic material of the body's cells. Folate or folic acid aids in cell maintenance and cell reproduction. Consuming adequate amounts of folate or folic acid also helps prevent folate-deficiency anemia. Sufficient folate intake during pregnancy helps reduce the risk of neural tube birth defects in infants.

• Food and drink sources: Asparagus, avocado, baked beans, banana, black-eyed peas, bread, broccoli, cantaloupe, cowpeas, egg noodles, fish, flour, fortified breakfast cereals, great northern beans, green beans, green leafy vegetables, legumes, lettuce, liver, orange, orange juice, papaya, pasta, peanuts, poultry, red meat, rice, spinach, tomatoes, turnip greens, wheat germ, and yeast.

• Recommended Dietary Allowance (RDA): The RDA for males and females older than age 14 is 400 micrograms. The RDA for breastfeeding adult women is 500 micrograms, and the RDA for pregnant adult women is 600 micrograms.

• Symptoms of deficiency: Anemia, apathy, diarrhea, fatigue, headaches, insomnia, loss of appetite, fetal neural tube defects, paranoia, shortness of breath, and weakness have been reported.

• Side effects of high oral doses: Very high doses may cause significant central nervous system (CNS) side effects, such as confusion, excitability, psychotic behavior, and seizures. Supplemental folic acid might increase seizures in people with seizure disorders, particularly in very high doses. However, the risks are low. High levels of folic acid may mask the signs of B12 deficiency, especially in older adults.

• Vitamin B1 (thiamin): Vitamin B1 helps the body convert energy from carbohydrates (sugars) into a form of energy that the body can use to power its activities. Vitamin B1 is also important for maintaining a healthy nervous system.

• Food and drink sources: Brewer's yeast, legumes, nuts, organ meats (such as liver and kidneys), pork, seeds, and whole-grain products.

• Recommended Dietary Allowance (RDA): The RDA for adults aged 19 years and older is 1.2 milligrams daily for males and 1.1 milligrams daily for females.

• Recommended Dietary Allowance (RDA) for adult women: 1.1 milligrams. The RDA for pregnant or breastfeeding women of any age is 1.4 milligrams daily, taken by mouth.

• Symptoms of deficiency: Confusion, constipation, digestive problems, irritability, loss of appetite, memory loss, nervousness, numbness of hands and feet, pain sensitivity, poor coordination, and weakness have been reported.

• Side effects of high oral doses: Thiamin is generally considered safe and relatively nontoxic, even at high doses. Large doses may cause drowsiness or muscle relaxation.

• Vitamin B2 (riboflavin): Vitamin B2 is necessary for normal cell function, growth, and energy production.

• Food and drink sources: Beef, bread, broccoli, cheese, collard greens, dairy products, eggs, enriched or fortified grain products, meats, noodles, organ meats (liver), spinach, and tuna.

• Recommended Dietary Allowance (RDA): The RDA for adults (by mouth) is 1 milligram for female adolescents (14-18 years old); 1.3 milligrams for male adolescents (14-18 years old); 1.1 milligrams for female adults (more than 18 years old); 1.3 milligrams for male adults (more than 18 years old); 1.4 milligrams for pregnant women (any age); and 1.6 milligrams for breastfeeding women (any age).

• Symptoms of deficiency: Blurred vision, cataracts, depression, dermatitis (skin inflammation), dizziness, hair loss, inflamed eyes, mouth lesions, nervousness, neurological symptoms (numbness, loss of sensation, "electric shock" sensations), seizures, sensitivity to light, sleepiness, and weakness have been reported.

• Side effects of high oral doses: In general, the limited capacity of human adults to absorb riboflavin taken by mouth limits its potential for harm. Riboflavin intake many times higher than the recommended dietary allowance (RDA) has not demonstrated toxicity. Nevertheless, the photosensitizing properties of riboflavin raise the possibility of some potential risks. Other possible reactions to very high doses include itching, numbness, burning or prickling sensations, and discolored urine.

• Vitamin B3 (niacin):Vitamin B3 helps the body process protein and fats. It is also important for maintaining a healthy nervous system and skin.

• Food and drink sources: Animal protein and whole grain products.

• Recommended Dietary Allowance (RDA): The RDA for adult men is 16 milligrams, and the RDA for adult women is 14 milligrams.

• Symptoms of deficiency: Bad breath, canker sores, confusion, depression, dermatitis (inflammation of the skin), diarrhea, emotional instability, fatigue, irritability, loss of appetite, memory impairment, muscle weakness, nausea, skin eruptions, and swelling have been reported.

• Side effects of high oral doses: Excessive doses of vitamin B3 may cause flushing (reddening of the skin) and upset stomach.

• Vitamin B5 (pantothenic acid): Vitamin B5 is a component of coenzyme A (CoA), a molecule that is necessary for many vital chemical reactions in cells. Vitamin B5 is essential for the metabolism of carbohydrates, proteins, and fats, as well as for the production of hormones and cholesterol.

• Food and drink sources: Animal products, legumes, and whole grain cereals.

• Recommended Dietary Allowance (RDA): The RDA for adult men and women is 5 milligrams.

• Symptoms of deficiency: Abdominal pains, burning feet, depression, eczema, fatigue, hair loss, immune impairment, insomnia, irritability, low blood pressure, muscle spasms, nausea, and poor coordination have been reported.

• Side effects of high oral doses: Moderate doses have been ingested without significant reported adverse effects. Large amounts of vitamin B5 taken by mouth may cause diarrhea. In theory, nausea and heartburn may occur.

• Vitamin B6 (pyridoxine): Vitamin B6 is needed for the production of the neurotransmitters (chemicals in the body that nerve cells use to send messages to other cells) serotonin and norepinephrine. Vitamin B6 is also needed produce myelin, the fatty covering that insulates nerves in the brain and spinal cord. Vitamin B6 helps the blood carry oxygen throughout the body. It is also important in breaking down copper and iron and for maintaining normal blood sugar levels.

• Food and drink sources: banana, bran, bread, chicken, chickpeas, fish, flour products, fortified breakfast cereal, garbanzo beans, kidney, lima beans, liver, oatmeal, pasta, peanut butter, pork, potato, roast beef, soybeans, spinach, starchy vegetables (such as corn and peas), sunflower seeds, tomatoes, trout, tuna, walnuts, and wheat bran.

• Recommended Dietary Allowance (RDA): The RDA for males (19-50 years old) is 1.3 milligrams; males (aged 51 years and older), 1.7 milligrams; females (19-50 years old), 1.3 milligrams; females (aged 51 years and older), 1.5 milligrams; pregnant women, 1.9 milligrams; and lactating women, 2 milligrams. Some researchers think the RDA for women 19-50 years old should be increased to 1.5-1.7 milligrams per day.

• Symptoms of deficiency: Acne, anemia, arthritis (joint inflammation), eye inflammation, depression, dizziness, facial oiliness, fatigue, irritability, loss of appetite, loss of hair, mouth lesions, nausea, and wound-healing problems have been reported.

• Side effects of high oral doses: Excessive doses of vitamin B6 may cause nerve damage in the arms and legs, with tingling, numbness, pain, or difficulty walking have been reported.

• Vitamin B12 (cobalamin, cyanocobalamin): Vitamin B12 helps maintain healthy nerve cells and red blood cells. Vitamin B6 is also needed to make DNA, the genetic material in all body cells.

• Food and drink sources: Beef, chicken, clams, dairy products, egg, fortified breakfast cereal, haddock, liver, milk, pork, salmon, shellfish, trout, tuna, and yogurt.

• Recommended Dietary Allowance (RDA): The RDAs are 2.4 micrograms per day for adults and adolescents aged 14 years and older, 2.6 micrograms per day for adult and adolescent pregnant females, and 2.8 micrograms per day for adult and adolescent lactating females.

• Symptoms of deficiency: Anemia, constipation, depression, dizziness, fatigue, intestinal disturbances, headaches, irritability, loss of vibration sensation, low stomach acid, mental disturbances, moodiness, mouth lesions, numbness, and spinal cord degeneration have been reported.

• Side effects of high oral doses: Reports of significant vitamin B12 toxicity are lacking.

• Vitamin C (ascorbic acid): Vitamin C is needed to form collagen in bones, cartilage, ligaments, muscle, tendon and blood vessels. It also aids iron absorption and has antioxidant effects.

• Food and drink sources: Broccoli, collard greens, grapefruit, guava, lemons, limes, oranges, peppers, potatoes, spinach, strawberries, and tomatoes.

• Recommended Dietary Allowance (RDA): The RDA for men older than 18 years is 90 milligrams per day; for women older than 18 years, 75 milligrams per day; for pregnant women older than 18 years, 85 milligrams per day; and for breastfeeding women older than 18 years, 120 milligrams per day.

• Symptoms of deficiency: Bleeding gums, depression, easy bruising, impaired wound healing, irritability, joint pain, loose teeth, malaise (general discomfort or uneasiness), and tiredness have been reported.

• Side effects of high oral doses: Excessive doses of vitamin C may cause upset stomach, kidney stones, severe diarrhea, and increased iron absorption. Rarely, flushing, faintness, dizziness, and fatigue have been noted. Large doses may cause hemolysis (red blood cell destruction) in patients with a deficiency in glucose-6-phosphate dehydrogenase (G6PD, an enzyme that is needed to keep the cell membranes of red blood cells intact). High doses of vitamin C should be avoided in people with conditions made worse by high acid levels in the body, such as cirrhosis, gout, renal tubular acidosis, or paroxysmal nocturnal hemoglobinuria (high levels of hemoglobin, a red blood cell protein, in the urine).

• Minerals:

• General: Mineral nutrients found in multivitamin or mineral supplements may include some or all of the following: calcium, chromium, copper, iodine, iron, magnesium, manganese, molybdenum, selenium, and zinc.

• Calcium: Calcium is needed for muscle contraction, blood vessel constriction and relaxation, the secretion of hormones and enzymes, and nervous system signaling.

• Food and drink sources: Dairy products, dark, leafy greens, and dried and cooked beans, which have varying amounts of absorbable calcium.

• Recommended Dietary Allowance (RDA): The RDA for calcium is 1,000 milligrams per day for adults (except pregnant or lactating women) and children over four years of age. This is used as the standard in nutrition labeling of foods.

• Symptoms of deficiency: Brittle nails, cramps, delusions, depression, insomnia, irritability, osteoporosis, palpitations (rapid, irregular heartbeat), periodontal disease (gum inflammation that may lead to bone loss), rickets, and tooth decay have been reported.

• Side effects of high oral doses: Loss of appetite, nausea, vomiting, constipation, abdominal pain, dry mouth, thirst, frequent urination, and calcium deposition in the heart and kidneys have been reported. Severe cases may cause confusion, delirium, coma, and, if not treated, death.

• Chromium: Chromium enhances insulin action and thus helps maintain normal blood glucose levels. It also is thought to play a direct role in protein, carbohydrate, and fat metabolism.

• Food and drink sources: Apple, banana, basil, beef, broccoli, garlic, grape juice, green beans, orange juice, potatoes, red wine, turkey breast, whole-wheat bread, and whole-wheat English muffins.

• Adequate intakes (AIs): For adult men (19-50 years old), the AI is 35 micrograms, and for women (19-50 years old), the AI is 25 micrograms.

• Symptoms of deficiency: Reports of chromium deficiency in humans are rare. Signs of chromium deficiency may include diabetes-like symptoms, such as impaired glucose tolerance, neuropathy, and weight loss.

• Side effects of high oral doses: Reports of adverse effects of high chromium intake are lacking.

• Copper: Copper helps regulate gene expression, mitochondrial function, cellular metabolism, and connective tissue formation, as well as the absorption, storage, and metabolism of iron.

• Food and drink sources: Avocado, beef, fruits, grains, legumes, nuts, shellfish, tap water that has passed through copper pipes, and vegetables.

• Recommended Dietary Allowance (RDA): The RDA is 900 micrograms for adults, 1,000 micrograms for pregnant women, 1,300 micrograms for nursing women, and 890 micrograms for adolescents 14-18 years old.

• Symptoms of deficiency: Anemia, arterial damage, depression, diarrhea, fatigue, fragile bones, hair loss, hyperthyroidism (excessive thyroid hormone production), and weakness have been reported.

• Side effects of high oral doses: Liver, kidney, or neurologic damage; weakness; abdominal pain; nausea; vomiting; and diarrhea have been reported.

• Iodine: The body needs iodine for thyroid hormone production (triiodothyronine; T3 and thyroxine; T4).

• Food and drink sources: The amount of iodine in food or water depends upon the amount of iodine in the local soil.

• Recommended Dietary Allowance (RDA): The RDA is 150 micrograms daily in adults aged 18 years and older (220 micrograms daily for pregnant women, 290 micrograms daily for breastfeeding women).

• Symptoms of deficiency: Cretinism (stunted mental and physical development resulting from an extreme deficiency of thyroid hormones), fatigue, hypothyroidism (abnormally low production of thyroid hormones), and weight gain have been reported.

• Side effects of high oral doses: Burning of the mouth, throat, and stomach; fever; nausea; vomiting; diarrhea; cardiovascular compromise; and loss of consciousness or coma have been reported.

• Iron: Iron is a component of proteins involved in metabolism and oxygen transport. Iron is also an essential cofactor in production of neurotransmitters, such as dopamine, norepinephrine, and serotonin.

• Food and drink sources: Meat, fish, poultry, beans, lentils, flours, cereals, grain products, dried fruit, peas, asparagus, leafy green vegetables, strawberries, and nuts.

• Recommended Dietary Allowance (RDA): The RDA for males (19- 50 years old) is 8 milligrams per day; for females (19- 50 years old), 18 milligrams per day; for adults (aged 51 years and older), 8 milligrams per day; for pregnant women (all ages), 27 milligrams per day; and for breastfeeding women (19 years and older), 9 milligrams per day.

• Symptoms of deficiency: Anemia, brittle nails, confusion, constipation, depression, dizziness, fatigue, headaches, inflamed tongue, and mouth lesions have been reported.

• Side effects of high oral doses: Arthritis, signs of gonadal failure (amenorrhea (the lack of a menstrual period), early menopause, loss of libido, impotence), shortness of breath, vomiting and diarrhea, cardiovascular or metabolic toxicity, and death have been reported.

• Magnesium: Magnesium is the fourth most plentiful mineral in the human body. Magnesium is required to maintain a steady heart rate to support the immune system and the functioning of muscles and nerves, and to build strong bones. In fact, about half of the body's magnesium is in the bones. Other functions of magnesium include maintaining normal blood pressure and modulating blood glucose levels.

• Food and drink sources: With the best sources listed first, good sources of magnesium are halibut, almonds, cashews, soybeans, spinach, shredded wheat, fortified oatmeal, potatoes, peanuts, wheat bran, black-eyed peas, yogurt, brown rice, lentils, avocado, kidney beans, pinto beans, wheat germ, chocolate milk, and bananas.

• Recommended Dietary Allowance (RDA): For men 19-30 years old, the RDA is 400 milligrams daily; for men 31 years and older, 420 milligrams daily; for women 19-30 years old, 310 milligrams daily; and for women 31 years and older, 320 milligrams daily.

• Symptoms of deficiency: In the United States, reports of magnesium deficiency are uncommon. When it does occur, magnesium deficiency may present initially with symptoms of fatigue, weakness, nausea, vomiting, and appetite loss. Symptoms of more severe magnesium deficiency include: abnormal heart rhythm, coronary spasms (short periods of heart muscle tightening), seizures, muscle cramps, numbness, tingling, and even personality changes.

• Side effects of high oral doses: Excess magnesium from magnesium supplements may cause abdominal cramps and diarrhea. Note that antacids and laxatives often contain magnesium. Taking antacids or laxatives may lead to the above symptoms. Signs of magnesium intake in great excess of amounts commonly found in foods mirror some of the symptoms found with magnesium deficiency. Symptoms may include appetite loss, diarrhea, nausea, irregular heartbeat, extremely low blood pressure, difficulty breathing, muscle weakness, and mental changes.

• Manganese: Manganese functions in bone formation and in carbohydrate, amino acid, and cholesterol metabolism.

• Food and drink sources: Grains and grain products, vegetables, and tea.

• Adequate Intake (AI): There is no RDA for manganese, due a lack of sufficient data. AI values were calculated from data on median intakes. The AI for adult women is 1.8 milligrams daily. The AI for adult men is 2.3 milligrams daily.

• Symptoms of deficiency: Finely scaling, slightly red skin rash has been reported.

• Side effects of high oral doses: Reports ofParkinson's disease-like neuromotor defects are linked to high manganese levels in drinking water. High levels may cause neurotoxicity.

• Molybdenum: Molybdenum is a cofactor required for the function of several human enzymes. Most known enzymes are proteins. Enzymes speed up the rate of chemical reactions in the body that would otherwise be too slow to support normal body functions.

• Food and drink sources: Molybdenum levels in plant-based foods depend upon the molybdenum concentration of the soil in which the food is raised. Food sources include primarily legumes, as well as nuts and grains.

• Recommended Dietary Allowance (RDA): The RDA for adult men and women is 45 micrograms daily.

• Symptoms of deficiency: Reports of molybdenum deficiency in healthy people are lacking.

• Side effects of high oral doses: Molybdenum toxicity data are lacking.

• Selenium: Selenium is a micromineral, which is a mineral that is needed by the body in very small amounts. Selenium is a component of selenoproteins, which are selenium-containing proteins. Selenoproteins function in regulating the thyroid gland, in the immune system, and as antioxidants.

• Food and drink sources: Food selenium content depends upon the amount of selenium in the soil where the food was raised. Thus the selenium content of foods may vary. Typically, Brazil nuts are by far the richest food source of selenium. Their selenium content is so high that regular consumption may lead to side effects. Other selenium-rich foods are canned tuna, beef, cod, turkey, chicken, enriched pasta, eggs, cottage cheese, fortified oatmeal, rice, and whole-wheat bread.

• Recommended Dietary Allowance (RDA): The RDA for adults is 80-200 micrograms taken by mouth. Specifically: 55 micrograms for female adults; 70 micrograms for male adults; 40-70 micrograms for adolescent males, 45-55 micrograms for adolescent females; 65 micrograms for pregnant females; and 75 micrograms for breastfeeding females.

• Reported symptoms of deficiency: Selenium deficiency is common in geographical regions with selenium-poor soil. Soil selenium levels in the United States are sufficient, and selenium deficiency is rare in this country. Research indicates that selenium deficiency may make the body more susceptible to illness. Symptoms of disease caused by selenium deficiency may include mental retardation, osteoarthropathy (a disease affecting the joints and bones), abnormal heart function, and an enlarged heart.

• Side effects of high oral doses: Selenosis is the medical term for abnormally high amounts of selenium in the blood. Symptoms of this condition include garlic breath, hair loss, irritability, fatigue, gastrointestinal problems, mild nerve damage, and white blotches on the nails.

• Zinc: Zinc helps the body grow and develop normally. It functions in cell reproduction, wound healing, immunity, and protein synthesis. People need zinc to maintain their sense of smell and taste.

• Food and drink sources: The human body does not store zinc, so people need to ingest zinc daily. Zinc may be found in many foods, including oysters (which are especially rich in zinc), beef, crab, pork, fortified breakfast cereal, chicken, lobster, baked beans, cashews, yogurt, chickpeas, cheese, almonds, milk, kidney beans, peas, oatmeal, and flounder.

• Recommended Dietary Allowance (RDA): The RDA for adult men is11 milligrams, and for adult women, 8 milligrams.

• Symptoms of deficiency: Zinc deficiency is uncommon in the United States. Zinc deficiency is typified by appetite loss, slow growth, and reduced immunity. Symptoms of more severe zinc deficiency may include eye and skin lesions, delayed wound healing, diarrhea, weight loss, hair loss, delayed sexual maturation, impotence, low testosterone levels in males, taste abnormalities, and mental sluggishness.

• Side effects of high oral doses: Conditions of chronic (developing over a period of time) and acute (rapid-developing) zinc toxicity exist. Symptoms of chronic zinc excess include altered iron function, low copper status, reduced immune function, and reduced levels of high-density lipoproteins (HDL; "good" cholesterol). Symptoms of acute zinc toxicity include abdominal cramps, appetite loss, diarrhea, nausea, vomiting, and headaches.

Function

• General: Doctors often recommend multivitamins to individuals who eat poor diets or who have difficulty absorbing nutrients. For example, multivitamins are usually recommended for people older than 60 years of age, because, as the body ages, it becomes more difficult to absorb certain vitamins, including vitamin B12. However, experts disagree whether or not multivitamins are necessary if a person is healthy and eats a well-balanced diet.

• Prenatal supplementation: Pregnant women are often prescribed prenatal vitamins to ensure that they get enough vitamins and minerals to support their fetuses. These prenatal vitamins may contain folic acid, calcium, and iron in higher amounts than are present in a typical multivitamin supplement.

• Healthcare professionals strongly recommend that women take a folic acid supplement at the start of pregnancy, and, if possible, even before conception. Folic acid is needed for the closing of the neural tube in the fetus. The neural tube develops into the brain and spinal cord. Folic acid thus helps prevent spina bifida, the most common neural tube defect and a serious condition in which the neural tube does not fully close. Spina bifida may cause impaired physical mobility, urinary and bladder problems, and learning disabilities.

• Prenatal vitamins that contain iron may help prevent anemia, one of the more common blood disorders, which occurs when the level of healthy red blood cells (RBCs) in the body becomes too low. RBCs contain hemoglobin, the protein that carries oxygen to the body's tissues. The recommended dietary allowance (RDA) for zinc is also higher for pregnant women.

• While nonpregnant women 19 years of age and older need 8 milligrams of zinc daily, pregnant women of the same age require 11 milligrams daily. Zinc is found in a number of brands of prenatal vitamins.

• Examples of vitamin deficiencies: Vitamin deficiencies may cause serious health problems. Symptoms of overall poor nutrition may include weight loss, diarrhea, abdominal cramps, gas, bloating, fatigue, foul-smelling or grayish stools that may be oily (called steatorrhea), stunted growth in children, and hollow brittle, bones (osteoporosis).

• Individuals who have specific vitamin deficiencies may develop potentially life-threatening health conditions. For instance, those who do not consume enough vitamin C may develop a condition called scurvy. Scurvy causes spongy, bleeding gums, bleeding under the skin, and extreme weakness. Although rare in the United States, scurvy may potentially cause sudden death. People with scurvy recover with vitamin C treatment.

• If people do not consume enough iron, they may develop iron deficiency anemia. According to the World Health Organization (WHO), iron deficiency is the most common and widespread nutritional disorder globally. Researchers estimate that iron deficiency anemia affects about 20% of women, 50% of pregnant women, and 3% of men in the United States. Iron is necessary for the bone marrow to produce hemoglobin, the protein in red blood cells that carries oxygen from the lungs to the body's tissues. If the body has inadequate levels of iron, there will not be enough hemoglobin for the red blood cells, and oxygen transport to the body's tissues will be impaired. Fatigue is a characteristic symptom of iron deficiency anemia. Although iron deficiency may occur as a result of blood loss (such as occurs in menstruation), this condition may also occur if the diet contains inadequate amounts of iron. In pregnant women, a growing fetus may deplete the mother's stored iron, resulting in the development of iron deficiency anemia in the mother. Thus iron supplements are frequently prescribed to pregnant women.

• Deficient levels of vitamin K, a fat-soluble vitamin, may lead to an increased risk of bleeding. Under these conditions, a person may bleed for a prolonged period of time after an injury.

• Individuals who do not consume enough vitamin D may develop a condition called osteomalacia. This condition causes softening and weakening of bones. Symptoms usually include bone fractures from a minor injury, muscle weakness, and widespread bone pain. When children develop osteomalacia, it is commonly called rickets. The human body is able to make all the vitamin D it needs with adequate sunlight exposure. Vitamin D is needed from food when sunlight exposure is inadequate.

• Those who do not consume enough niacin (vitamin B3) may develop a condition called pellagra. Symptoms may include dementia, skin lesions, inflammation or reddening of the tongue, mouth pain and ulcers, increased salivation, burning in the throat, abdominal pain and swelling, constipation, diarrhea, nausea, and vomiting. This condition is rare in developed countries such as the United States. It is most common in areas of the world where malnutrition is prevalent.

Theory/Evidence

• Strong scientific evidence:

• Biotin: Biotin (vitamin H; vitamin B7) is a water-soluble vitamin that is needed for carbohydrate and protein metabolism.

• Biotin deficiency: Strong scientific evidence supports biotin supplementation for the treatment of biotin deficiency. In general, biotin deficiency is rare, because there are many food sources of biotin, and the body is able to recycle much of its unused biotin. Some potential causes of biotin deficiency are: long-term use of certain antiseizure medications; long-term use of antibiotics taken by mouth; poor intestinal absorption (for example, short bowel syndrome); intravenous feeding (total parenteral nutrition; TPN) without added biotin; and eating raw egg whites on a regular basis.

• Biotin-responsive inborn errors of metabolism: Disorders such as multiple carboxylase deficiency may cause inborn errors of metabolism that cause a "functional" biotin deficiency. High-dose biotin is used to treat these disorders. Management should be under strict medical supervision.

• Avoid if hypersensitive to constituents of biotin supplements.

• Calcium: Calcium is the most abundant mineral in the human body. To treat calcium disorders, calcium is given in various chelated forms. Chelated calcium has been chemically bonded to another molecule. Calcium citrate is an example of such a preparation. Calcium may also be combined with other substances to form preparations such as calcium lactate, calcium gluconate, or calcium carbonate.

• Antacid (calcium carbonate): Calcium carbonate is a U.S. Food and Drug Administration (FDA)-approved over-the-counter (OTC) drug used to treat gastric hyperacidity (high acid levels in the stomach).

• Bone loss (prevention): Multiple studies of calcium supplementation in the elderly and postmenopausal women have found that high calcium intakes may help reduce the loss of bone density. Studies indicated that bone loss could be prevented in many bones, including those of the ankles, hips, and spine.

• Cardiopulmonary resuscitation (CPR): Calcium chloride may be given intravenously (IV) by a qualified healthcare professional in cardiac resuscitation, particularly after open-heart surgery, if epinephrine fails to improve weak or ineffective myocardial contractions. Calcium chloride is contraindicated for cardiac resuscitation in the presence of ventricular fibrillation (uncoordinated contraction of the cardiac muscle in the heart's ventricles). CPR with calcium chloride should be performed only under the supervision of a qualified healthcare professional.

• Deficiency (calcium): Calcium gluconate is used to treat conditions arising from calcium deficiencies, such as hypocalcemic (low blood calcium) tetany (muscle spasms), hypocalcemia related to hypoparathyroidism (low levels of the parathyroid hormone), and hypocalcemia due to rapid growth or pregnancy. It is also used for the treatment of hypocalcemia for conditions requiring a prompt increase in plasma calcium levels (e.g., tetany in newborns and tetany due to parathyroid deficiency, vitamin D deficiency, and alkalosis (a condition in which body fluids have too much base, as opposed to too much acid, or acidosis)) and for the prevention of hypocalcemia during exchange transfusions. Treatment of hypocalcemia should only be done under supervision of a qualified healthcare professional.

• High blood phosphate level: Hyperphosphatemia (high phosphate level in the blood) is associated with increased cardiovascular mortality in adult dialysis patients. Calcium carbonate or calcium acetate may be used effectively to bind and remove phosphate. Use may increase calcium phosphate products in blood. Treatment of hyperphosphatemia should only be done under supervision of a qualified healthcare professional.

• Osteoporosis: Osteoporosis is a skeletal disorder in which bone mass and strength is reduced, resulting in increased risk of fracture. Although osteoporosis is most commonly diagnosed in white postmenopausal women, women of other racial groups and ages, men, and children may also develop osteoporosis. Calcium is the nutrient consistently found to be the most important for attaining peak bone mass and preventing osteoporosis. Adequate vitamin D intake is required for optimal calcium absorption. Adequate calcium and vitamin D are deemed essential for the prevention of osteoporosis in general, including postmenopausal osteoporosis. Although calcium and vitamin D alone are not recommended as the sole treatment for osteoporosis, they are necessary additions to pharmaceutical treatments. The vast majority of clinical trials investigating the efficacy of pharmaceutical treatments for osteoporosis have investigated these agents in combination with calcium and vitamin D. So, although calcium alone is unlikely to have an effect on the rate of bone loss following menopause, osteoporosis cannot be treated in the absence of calcium. Treatment of postmenopausal osteoporosis should only be done under supervision of a qualified healthcare professional.

• Toxicity (magnesium): Intravenous calcium gluconate may help alleviate symptoms of hypermagnesemia (high levels of magnesium in the blood). Treatment of magnesium toxicity should only be done under supervision of a qualified healthcare professional.

• Avoid if allergic to calcium or lactose. High doses (more than 1,000 milligrams in men and women aged 19-50 year and more than 1,200 milligrams in individuals older than age 50) taken by mouth may cause kidney stones. Avoid with high levels of calcium in the blood or urine, high levels of parathyroid hormone, bone tumors, digitalis toxicity, ventricular fibrillation (uncoordinated contraction of ventricular cardiac muscle in the heart), kidney stones, kidney disease, kidney failure, high serum phosphate levels, or sarcoidosis (nodule formation in the liver, lymph glands, lungs, and salivary glands). Calcium supplements made from dolomite (sedimentary rock and mineral composed of calcium magnesium carbonate), oyster shells, or bone meal may contain unacceptable levels of lead. Use cautiously in those with low levels of stomach acid (achlorhydria) or an irregular heartbeat. Calcium appears to be safe in pregnant or breastfeeding women when used at recommended doses.

• Copper: Copper is a mineral that occurs naturally in many foods, including vegetables, legumes, nuts, grains, fruits, shellfish, avocado, beef, and animal organs.

• Copper deficiency: Copper deficiency may occur in infants fed formula prepared from cow milk only (relatively low in copper content), in premature or low-birthweight infants, and infants with prolonged diarrhea or malnutrition. Copper deficiency may also occur in individuals with malabsorption syndromes (such as celiac disease, sprue, or short bowel syndrome), individuals with cystic fibrosis, the elderly, or those receiving intravenous total parenteral nutrition (TPN) or who are on other restrictive diets. Such individuals may require supplementation with copper (and other trace elements).

• Avoid if allergic to copper. Avoid use of copper supplements when recovering from diarrhea, because excess copper may worsen symptoms. Avoid with hypercupremia (excess copper in the blood). Avoid with genetic disorders affecting copper metabolism (e.g., Wilson's disease, Indian childhood cirrhosis, or idiopathic copper toxicosis). Avoid in those with HIV or AIDS. Use caution when using tap water that contains more than 6 milligrams of copper per liter to prepare food or drinks. Use cautiously in those with anemia, joint pain, muscle pain, or those at risk for selenium deficiency. Use cautiously if taking birth control pills.

• Folate (folic acid): Folate occurs naturally in food. Folic acid is the synthetic form of the vitamin, which is in multivitamins and other dietary supplements.

• Folate deficiency: Folate deficiency occurs if the body does not get an adequate amount of folate from dietary intake or folic acid from supplements. Folic acid has been shown to be effective in the treatment of megaloblastic anemia that is the result of folate deficiency. Anemia is a disorder in which the body does not make enough red blood cells. In megaloblastic anemia, the red blood cells are abnormally large. Patients with anemia should be evaluated by a physician in order to diagnose and address the underlying cause.

• Prevention of pregnancy complications: Studies suggest that folate consumption during pregnancy helps prevent folate deficiency and anemia in pregnant women. Low folate levels during pregnancy may contribute to birth defects and pregnancy loss. Consuming a high dietary intake of folate and taking folic acid supplements by mouth during pregnancy reduce the risk of neural tube birth defects and cleft palate in the infant.

• Avoid if allergic to folate or any of the product ingredients. It is recommended that pregnant women consume 600 micrograms daily in order to reduce the risk of birth defects. Folate is likely safe when breastfeeding if consumed at the recommended dietary allowance (RDA) of 500 micrograms daily.

• Iodine: Iodine is an element that the human body needs to make thyroid hormones.

• Goiter prevention: Iodine deficiency is one of the causes of goiter (enlargement of the thyroid gland as it tries to make more thyroid hormone in the absence of iodine). Physically, goiter appears as an abnormal enlargement of the thyroid gland in the neck. Although goiter due to low iodine intake is rare in developed countries, it may occur in regions with low levels of iodine in the soil. To avoid iodine deficiency in the United States, table salt is enriched with iodine ("iodized" salt) and iodine is added to cattle feed and used as a dough conditioner. Iodine supplementation is generally not recommended in developed countries where sufficient iodine intake is common, and excess iodine may actually cause medical complications (including goiter). Iodine supplementation should be considered in cases of known iodine deficiency and should be administered with medical supervision if possible. Notably, the treatment of goiter usually involves the administration of thyroid hormone, most commonly levothyroxine sodium (Synthroid®, Levoxyl®, Levothroid®). Iodine generally does not play a role in the acute management of this condition.

• Iodine deficiency: In regions with low iodine intake or cases of known deficiency, iodine-enriched foods or supplementation should be considered. When considering iodine enrichment or supplementation, supervision by medical personnel or public health officials is recommended, due to the potential complications involved with iodine replacement in the setting of previous deprivation, particularly if considering supplementation in pregnant women or children.

• Radiation emergency (potassium iodide thyroid protection): Potassium iodide (KI) may be taken in the setting of radiation exposure in order to reduce levels of radioactive iodine uptake by the thyroid, thus reducing the risk of later developing thyroid cancer. It is important to note that KI does not provide immediate protection from radiation damage and does not have protective effects against other complications of radiation exposure. KI may serve as a part of a general strategy in cases of radiation emergencies, in conjunction with shelter and control of foodstuffs. Many radiation emergency kits include KI.

• Skin disinfection/sterilization: Iodine is commonly used in topical disinfectant preparations for cleaning wounds, sterilizing skin before surgical or other invasive procedures, or sterilizing catheter entry sites. Betadine® solution, for example, contains povidone-iodine. Other topical disinfectants include alcohol and antibiotics, and iodine is sometimes used in combination with these. Commercially prepared iodine products are recommended in order to assure appropriate concentrations.

• Water purification: Iodine is used as an antimicrobial agent for emergency water purification. Tablets and solutions are commercially available. Treatment is usually effective within 15 minutes.

• Supplements should be taken under the supervision of a healthcare provider. There have been reports of severe and even fatal reactions to iodine. Avoid iodine-based products if allergic to iodine. Do not use for more than 14 days. Lugol solution and saturated solution of potassium iodide (SSKI, PIMA) should be avoided in patients with pulmonary edema, bronchitis, or known tuberculosis or hyperkalemia (above-normal potassium blood levels), because of potential side effects from excess iodine or potassium. Use cautiously when applying to the skin, because iodine may irritate or burn tissues. Use sodium iodide cautiously in those with kidney failure or gastrointestinal obstruction (blockage in the stomach and intestine). Iodine is safe in recommended doses for pregnant or breastfeeding women. Avoid povidone-iodine (a widely used antiseptic preparation of polyvinylpyrrolidone and iodine) for perianal (around the anus) preparation during delivery. Avoid povidone-iodine for preventing infection after delivery.

• Iron: Iron is an essential mineral.

• Anemia of chronic disease: Taking iron by mouth with epoetin alfa (erythropoietin, EPO, Epogen®, Procrit®) is effective for treating anemia associated with chronic renal failure and chemotherapy.

• Iron deficiency anemia: Ferrous sulfate (Feratab®, Fer-Iron®, Slow-FE®) is the standard treatment for treating iron deficiency anemia. Dextran-iron (INFeD®) is given intravenously by healthcare providers to restore adequate iron levels in bone marrow when therapy using iron by mouth has failed. Ferrous fumarate (Ferretts® or Hemocyte®) has also been used.

• Allergic reactions to iron are unlikely. Avoid if allergic to products containing iron. Avoid excessive intake. Avoid iron supplements with blood disorders that require frequent blood transfusions. Use iron supplement cautiously with a history of kidney disease, intestinal disease, heart disease, peptic ulcer disease, enteritis (inflammation of the small intestine), colitis (inflammation of the colon, or large intestine), pancreatitis (inflammation of the pancreas), hepatitis (inflammation of the liver), or alcoholism. Use cautiously if older than 55 years old, as use may increase the risk of heart disease. Pregnant or breastfeeding women should consult their healthcare professionals before beginning iron supplementation.

• Magnesium: Magnesium is a mineral nutrient. Good sources of dietary magnesium include green vegetables (such as spinach), whole grains, nuts, legumes, and halibut.

• Pre-eclampsia (and eclampsia): Pre-eclampsia is a condition that may occur in the second half of pregnancy and is characterized by high blood pressure and excess protein in the urine. According to secondary sources, pre-eclampsia may occur in 10% of all pregnancies. Eclampsia is a severe, potentially fatal condition that may develop when pre-eclampsia is left untreated. Healthcare professionals commonly inject magnesium sulfate into the veins in cases of patients with pre-eclampsia and eclampsia. Magnesium sulfate is considered a superior drug for the prevention of the recurrence of seizures in eclampsia and in seizure prevention in pre-eclampsia. A common, but not serious, side effect of magnesium sulfate therapy is flushing (reddened skin, especially on the neck and cheeks). Magnesium injected into the vein may also cause low blood pressure, slow heart rate, excessive sweating, eruption of itching skin welts, and breathing problems.

• Avoid in patients with known allergy to magnesium or other products found in magnesium supplements. Magnesium allergy is reported to be extremely rare. Magnesium may cause stomach irritation, nausea, vomiting, diarrhea, decreased skeletal muscle tone, and decreased estrogen levels. High blood levels of magnesium (hypermagnesemia) may cause thirst; drowsiness; low blood pressure; delirium; coma; heart, muscle, and respiratory disorders; and death. Toxic levels of magnesium may cause depression of the central nervous system. Magnesium may increase the risk of bleeding, and caution is advised in patients with bleeding disorders or those who are taking drugs, such as warfarin (Coumadin®), that may increase the risk of bleeding. Dosing adjustments may be necessary. Avoid in patients with kidney disorders and atrioventricular heart block (when the electric signal from the heart's upper to lower chambers is not being sent correctly). Avoid using magnesium as a laxative in patients with stomach disorders. Patients taking antidiabetic agents, blood pressure-lowering agents, or antibiotics (such as fluoroquinolones and cephalosporins) should use magnesium cautiously. Side effects appear to be uncommon with therapeutic doses of magnesium in infants or women who are pregnant or breastfeeding. According to the National Institute of Health's Lactation and Toxicology Database (LactMed), magnesium sulfate and magnesium hydroxide are acceptable to use during breastfeeding.

• Niacin: Niacin (Vitamin B3) is a B-complex vitamin found in many foods, including liver, poultry, fish, nuts, and dried beans.

• High cholesterol (niacin): Niacin is an established treatment for high cholesterol. Multiple studies show that niacin (not niacinamide) has significant benefits on levels of high-density cholesterol (HDL, or "good," cholesterol), with better results than prescription drugs such as statins like atorvastatin (Lipitor®). There are also beneficial effects on levels of low-density cholesterol (LDL, or "bad," cholesterol), although these effects are less dramatic. Using niacin together with a second drug such as a statin may increase the effects on low-density lipoproteins. The use of niacin for the treatment of dyslipidemia (abnormal amounts of lipids in the blood) associated with type 2 diabetes has been controversial, because of the possibility of worsening glycemic control (control of blood glucose levels). Patients should check with their physicians and pharmacists before starting niacin.

• Pellagra (niacin): Niacin (vitamin B3) and niacinamide are U.S. Food and Drug Administration (FDA)-approved for the treatment of niacin deficiency. Pellagra is a nutritional disease that develops due to insufficient dietary amounts of niacin or the chemical it is made from, tryptophan. Symptoms of pellagra include skin disease, diarrhea, dementia, and depression.

• Avoid niacin (vitamin B3) if allergic to niacin or niacinamide. Avoid with a history of liver disease, irregular heartbeat, heart disease, blood clotting, bleeding disorders, asthma, anxiety, panic attacks, thyroid disorders, stomach ulcers, gout, or diabetes. Avoid if pregnant or breastfeeding.

• Pantothenic acid (vitamin B5): Pantothenic acid (vitamin B5) is found in many foods, including, meats, liver, kidney, fish, shellfish, chicken, vegetables, legumes, yeast, eggs, and milk.

• Pantothenic acid deficiency: Pantothenic acid deficiency has been very rarely observed in humans. In cases of true pantothenic acid deficiency, treatment with pantothenic acid by mouth is acceptable. It may also be merited as prevention in select patients at high risk for malnutrition. It should be included in tube feeds or parenteral (intravenous) nutrition formulas for patients unable to eat on their own.

• Avoid if allergic to pantothenic acid or dexpanthenol, which is converted to pantothenic acid in the body. Avoid with gastrointestinal blockage. Pantothenic acid is generally considered safe in pregnant and breastfeeding women when taken at recommended doses.

• Riboflavin: Riboflavin (vitamin B2) is a vitamin that is needed for normal cell function, growth, and energy production.

• Neonatal jaundice: Riboflavin supplementation is included in the treatment of neonatal jaundice with phototherapy (light therapy).

• Riboflavin deficiency (ariboflavinosis): Studies suggest that riboflavin is beneficial in patients with riboflavin deficiency (ariboflavinosis). Ariboflavinosis may cause weakness, throat swelling or soreness, glossitis (tongue swelling), angular stomatitis or cheilosis (skin cracking or sores at the corners of the mouth), dermatitis (skin irritation), or anemia. Some groups may be particularly susceptible to riboflavin deficiency, including the elderly, those with chronic illnesses, the poor, and those with alcohol dependency. Patients with suspected riboflavin deficiency should be evaluated by qualified healthcare professionals.

• Avoid if allergic to riboflavin. Because the amount of riboflavin a human can absorb is limited, riboflavin is generally considered safe. Riboflavin is generally regarded as being safe during pregnancy and breastfeeding when taken at the recommended dietary allowance (RDA) of 1.4 milligrams daily.

• Thiamin (thiamine), vitamin B1: Thiamin (thiamine), also called vitamin B1, is a water-soluble vitamin.

• Metabolic disorders (subacute necrotizing encephalopathy, maple syrup urine disease, pyruvate carboxylase deficiency, hyperalaninemia): Taking thiamin by mouth helps to temporarily correct some complications of metabolic disorders associated with genetic diseases, including subacute necrotizing encephalopathy (SNE; Leigh's disease), maple syrup urine disease (branched-chain aminoacidopathy), and lactic acidosis associated with pyruvate carboxylase deficiency and hyperalaninemia. Long-term management should be under strict medical supervision.

• Thiamin deficiency (beriberi, Wernicke's encephalopathy, Korsakoff's psychosis, Wernicke-Korsakoff syndrome): Humans depend on dietary intake to meet their thiamin requirements. Because people are unable to store much thiamin, depletion may occur as quickly as within 14 days. Severe chronic thiamin deficiency may result in potentially serious complications involving the nervous system and brain, muscles, heart, and gastrointestinal system. Patients with thiamin deficiency or related conditions should receive supplemental thiamin under medical supervision.

• Thiamin is generally considered safe and relatively nontoxic, even at high doses. Avoid if allergic or hypersensitive to thiamin. Thiamin appears safe if pregnant or breastfeeding when taken at the recommended dietary allowance of 1.4 milligrams daily.

• Vitamin A: Vitamin A is a fat-soluble vitamin that is needed for vision.

• Acne: Derivatives of vitamin A, retinoids, are used to treat skin disorders such as acne. Prescription medications that can be taken by mouth or applied directly to the skin, including tretinoin (Avita®, Renova®, Retina-A®, Retin-A Micro®) and isotretinoin (Accutane®), are available. Isotretinoin may cause severe side effects and should be used only for severe acne that is resistant to other treatments. Isotretinoin must not be used in women who are pregnant, trying to become pregnant, or who may become pregnant, due to a risk of severe birth defects. Treatment should be under the supervision of a qualified licensed healthcare professional. Vitamin A supplements should not be used simultaneously with retinoids, due to a risk of increased toxicity.

• Acute promyelocytic leukemia (treatment, All-trans retinoic acid): The prescription drug All-Trans-Retinoic Acid (ATRA; Vesanoid®) is a vitamin A derivative that is an established treatment for acute promyelocytic leukemia and improves median survival in patients with this disease. Treatment should be under strict medical supervision. Vitamin A supplements should not be used simultaneously with ATRA, due to a risk of increased toxicity.

• Eye disorders (Bitot's spot): Vitamin A deficiency may lead to Bitot's spot, or the buildup of keratin debris in the conjunctiva. Bitot's spot is a sign of xerophthalmia and may be treated with vitamin A supplementation.

• Measles (supportive agent): Vitamin A should be administered to children diagnosed with measles in areas where vitamin A deficiency may be present. Measles, a viral disease, may lead to serious complications, such as diarrhea, pneumonia, and encephalitis. Supplementation with vitamin A in children with measles decreases the length and impact of the disease. Management of measles should be under strict medical supervision.

• Vitamin A deficiency: Vitamin A deficiency may occur after chronic lack of adequate amounts of vitamin A or beta-carotene. Vitamin A is necessary for vision, and an early sign of vitamin A deficiency is keratomalacia (night blindness). Prolonged deficiency may lead to xerophthalmia (dry eye) and Bitot's spot, or the buildup of keratin debris in the conjunctiva. Eventually, blindness may occur due to damage to the retina and cornea. Vitamin A is necessary for healthy growth and development, and recommended daily amounts (RDA) should be assured, particularly in children.

• Xerophthalmia (dry eye): Oral vitamin A is the treatment of choice for xerophthalmia, which results from prolonged vitamin A deficiency. Oral vitamin A should be given immediately once the disorder is established.

• Avoid if allergic to vitamin A. intake levels. Use cautiously in those with liver disease or alcoholism. Smokers who consume alcohol and beta-carotene may have an increased risk of developing lung cancer or heart disease. Vitamin A appears safe in pregnant women if taken in recommended doses. Use cautiously if breastfeeding, because the benefits or dangers to nursing infants are not clearly established.

• Vitamin B6: Vitamin B6 (pyridoxine) is commonly found in cereal grains, legumes, vegetables (e.g., carrots, spinach, peas, or potatoes), milk, cheese, eggs, fish, liver, meat, and flour.

• Hereditary sideroblastic anemia: Pyridoxine supplements are effective for treatment of some hereditary sideroblastic anemias (a condition where available iron cannot be incorporated into hemoglobin) under the supervision of a qualified healthcare provider.

• Preventing adverse effects in people taking cycloserine (Seromycin©): Cycloserine is a prescription antibiotic that may cause anemia, peripheral neuritis, or seizures by acting as a pyridoxine antagonist or increasing excretion of pyridoxine. Requirements for pyridoxine may be increased in patients receiving cycloserine. Pyridoxine may be recommended by a healthcare provider to prevent these adverse effects.

• Pyridoxine deficiency/neuritis: Pyridoxine supplements are effective for preventing and treating pyridoxine deficiency and neuritis due to inadequate dietary intake, certain disease states, or deficiency induced by drugs such as isoniazid (INH) or penicillamine. Dietary supplements should be taken under the guidance of a qualified healthcare provider.

• Pyridoxine-dependent seizures in newborns: Pyridoxine-dependent seizures in newborns may result from the use of high-dose pyridoxine in pregnant mothers or from genetic (autosomal recessive) pyridoxine dependency. Refractory seizures in newborns that are caused by pyridoxine dependence may be controlled quickly with intravenous administration of pyridoxine by a qualified healthcare provider.

• Some individuals are particularly sensitive to vitamin B6 and may experience side effects at lower doses. Avoid excessive dosing. Vitamin B6 is likely safe when taken by mouth in doses that do not exceed the recommended dietary allowance (RDA).

• Vitamin B12: Vitamin B12 is a water-soluble vitamin and is commonly found in many foods like fish, shellfish, meats, and dairy products. Vitamin B12 helps maintain healthy nerve cells and red blood cells.

• Megaloblastic anemia due to vitamin B12 deficiency: Vitamin B12 deficiency is a cause of megaloblastic anemia. In this type of anemia, red blood cells are larger than normal, and the ratio of nucleus size to cell cytoplasm is increased. There are other potential causes of megaloblastic anemia, including folate deficiency or various inborn metabolic disorders. If the cause is B12 deficiency, then treatment with B12 is the standard approach. Patients with anemia should be evaluated by a qualified healthcare provider in order to diagnose and address the underlying cause.

• Pernicious anemia: Pernicious anemia (blood abnormality) is a form of anemia that occurs when there is an absence of intrinsic factor, a substance normally present in the stomach. Vitamin B12 binds with intrinsic factor before it is absorbed and used by the body. An absence of intrinsic factor prevents normal absorption of B12 and may result in pernicious anemia. Pernicious anemia treatment is usually lifelong; supplemental vitamin B12 given intramuscularly, intranasally (through the nose), or by mouth.

• Vitamin B12 deficiency: Studies have shown that a deficiency of vitamin B12 may lead to neurologic and psychiatric symptoms. These symptoms may include: ataxia (shaky movements and unsteady gait), muscle weakness, spasticity, incontinence, low blood pressure, vision problems, dementia, psychoses, and mood disturbances. Researchers have reported that these symptoms may occur when vitamin B12 levels are just slightly lower than normal and considerably above the levels normally associated with anemia. People at risk for vitamin B12 deficiency include strict vegetarians, elderly people, breastfed infants, and people with increased vitamin B12 requirements associated with pregnancy, thyrotoxicosis (increased levels of thyroid hormones in the blood), hemolytic anemia, hemorrhage, malignancy, or liver or kidney disease. Administering vitamin B12 by mouth, intramuscularly or intranasally effectively prevents and treats dietary vitamin B12 deficiency.

• Avoid vitamin B12 supplements if allergic to cobalamin, cobalt, or any other product ingredients. Avoid with coronary stents or Leber's disease (a hereditary condition marked by acute loss of vision). Use cautiously if undergoing angioplasty (mechanical widening of a narrowed or obstructed blood vessel). Vitamin B12 is generally considered safe when taken in amounts that are not higher than the recommended dietary allowance (RDA).

• Vitamin C (ascorbic acid): Vitamin C (ascorbic acid) is a vitamin that the body needs to form collagen in bones, cartilage, muscle, and blood vessels.

• Vitamin C deficiency (scurvy): Scurvy is caused by a dietary deficiency of vitamin C. Although scurvy is uncommon, it may occur in malnourished individuals, those with increased vitamin C requirements (such as pregnant or breastfeeding women), or in infants whose only source of nourishment is breast milk. Vitamin C administered by mouth or injection is effective for curing scurvy. If vitamin C is not available, orange juice may be used for infantile scurvy. Symptoms should begin to improve within 24-48 hours, with resolution within seven days. Treatment should be under strict medical supervision.

• Vitamin C is generally considered safe in the amounts commonly found in foods. Vitamin C supplements are also generally considered safe in most individuals if taken in recommended doses. Avoid high doses of vitamin C with glucose-6-phosphate dehydrogenase (G6PD) deficiency, kidney disorders or stones, cirrhosis (scarring and poor function of the liver as a result of chronic liver disease), gout, or paroxysmal nocturnal hemoglobinuria (a bleeding disorder). Vitamin C intake from food is generally considered safe if pregnant or breastfeeding. It is not clear if vitamin C supplements in doses higher than dietary reference intake recommendations are safe for pregnant or breastfeeding women. Vitamin C is naturally found in breast milk.

• Vitamin D: Vitamin D is found in many foods, including fish, eggs, fortified milk, and cod liver oil. Vitamin D is also made by the skin when exposed to sunlight.

• Familial hypophosphatemia: Familial hypophosphatemia (low levels of phosphate in the blood) is a rare inherited disorder that consists of faulty phosphate transport in the blood and reduced vitamin D metabolism in the kidneys. Familial hypophosphatemia is a cause of rickets. Taking calcitriol (a form of vitamin D) or dihydrotachysterol (a chemical with structure and activity similar to vitamin D) by mouth along with phosphate supplements is effective for treating bone disorders in people with familial hypophosphatemia. Management should be under medical supervision.

• Fanconi syndrome-related hypophosphatemia: Fanconi syndrome is a kidney disease characterized by passing large volumes of urine and by bone pain and weakness. Taking ergocalciferol (a form of vitamin D, also known as vitamin D2) by mouth is effective for treating hypophosphatemia associated with Fanconi syndrome.

• Hyperparathyroidism due to low vitamin D levels: Some patients may develop secondary hyperparathyroidism due to low levels of vitamin D. The initial treatment for this type of hyperparathyroidism is supplemental vitamin D. For patients with primary or refractory hyperparathyroidism, surgical removal of the parathyroid glands is common. Studies also suggest that vitamin D supplementation may reduce the incidence of hypoparathyroidism following surgery for primary hyperparathyroidism (partial or total removal of the parathyroid glands).

• Hypocalcemia due to hypoparathyroidism: Hypoparathyroidism (low blood levels of parathyroid hormone) is rare, and is often due to surgical removal of the parathyroid glands. High doses of dihydrotachysterol (DHT), calcitriol, or ergocalciferol taken by mouth may assist in increasing serum calcium concentrations in people with hypoparathyroidism or pseudohypoparathyroidism.

• Osteomalacia (adult rickets): Adults with severe vitamin D deficiency lose bone mineral content and experience bone pain, muscle weakness, and osteomalacia (soft bones). Osteomalacia may be found among elderly patients with vitamin D-deficient diets, people with decreased absorption of vitamin D or with inadequate sun exposure (such as those living in latitudes with seasonal reduced day lengths), patients who have had gastric or intestinal surgery, patients with aluminum-induced bone disease, patients with chronic liver disease, or patients with chronic kidney disease. Treatment for osteomalacia depends on the underlying cause of the disease and often includes pain control and orthopedic surgical intervention, as well as vitamin D and phosphate-binding agents.

• Psoriasis: Psoriasis is a common skin condition characterized by redness, irritation, and the presence of silver-white patches called scales. A number of different approaches are used in the treatment of psoriasis. Mild approaches include light therapy, stress reduction, moisturizers, or salicylic acid to remove scaly skin areas. For more severe cases, treatments may include UV-A light, psoralen plus UV-A light (PUVA), retinoids such as isotretinoin (Accutane), corticosteroids, or cyclosporine (Neoral®, Sandimmune®). The synthetic vitamin D3 analog calcipotriene (Dovonex®) appears to control skin cell growth and is used for moderately severe skin plaques, particularly for skin lesions resistant to other therapies or located on the face. Vitamin D3 (tacalcitol) ointment has been reported as being safe and well tolerated. High doses of becocalcidiol (a vitamin D analog) used on the skin may be beneficial in the treatment of psoriasis.

• Rickets: Rickets develop in children with vitamin D deficiency. Infants fed only breast milk (without supplemental vitamin D) may also develop rickets. Although now rare, partially due to the availability of vitamin D-fortified milk, there has been a recent increase in rickets among children in latitudes with periodic, seasonal lack of sufficient sunlight. Ergocalciferol or cholecalciferol is effective for treating vitamin D deficiency rickets. Calcitriol should be used in patients with kidney failure. Treatment should be under medical supervision.

• Avoid if allergic or hypersensitive to vitamin D or any of its components. Vitamin D is generally well tolerated in recommended doses. Doses higher than recommended may cause toxic effects. Individuals with hyperparathyroidism (overactive thyroid), kidney disease, sarcoidosis (nodule formation in the liver, lymph glands, lungs, and salivary glands), tuberculosis, or histoplasmosis (a fungal infection that affects the lungs) have a higher risk of experiencing toxic effects. Vitamin D is generally considered safe for pregnant women. It may be necessary to give infants vitamin D supplements along with breast milk.

• Vitamin E: Vitamin E exists in eight different forms: alpha-, beta-, gamma-, and delta-tocopherol; and alpha-, beta-, gamma-, and delta- tocotrienol. Alpha-tocopherol is the most active form in humans.

• Vitamin E deficiency: Vitamin E deficiency is rare but may occur in people with diminished fat absorption through the gut (due to surgery, Crohn's disease, or cystic fibrosis), malnutrition, very-low-fat diets, several specific genetic conditions (such as abetalipoproteinemia or ataxia and vitamin E deficiency), very-low-birthweight premature infants, or infants receiving unfortified formulas. Vitamin E supplementation is accepted as an effective therapy for vitamin E deficiency to halt progression of complications. Diagnosis of this condition and management should be under the care of a physician and nutritionist.

• Avoid if allergic or hypersensitive to vitamin E. When taken for short periods of time, vitamin E supplementation is generally considered safe when consumed in recommended dosages.

• Vitamin K: Vitamin K is found in green leafy vegetables, broccoli, asparagus, cauliflower, green peas, beans, olives, canola, soybeans, meat, cereals, and dairy products.

• Hemorrhagic disease of newborn (vitamin K deficiency bleeding; VKDB): Vitamin K deficiency in infants may lead to hemorrhagic disease of the newborn, also known as vitamin K deficiency bleeding (VKDB). Although up to half of newborns may have some degree of vitamin K deficiency, serious hemorrhagic disease with bleeding is rare. Because vitamin K given by injection has been shown to prevent VKBD in newborns and young infants, the American Academy of Pediatrics recommends administering a single intramuscular injection of vitamin K1 to all newborns. A dose taken by mouth is not considered adequate as prevention, particularly in breastfeeding infants. Initial concerns of cancer risk were never proven and are generally not considered clinically relevant. Treatment: In cases of true VKDB, bleeding may occur at injection sites, at the umbilicus, or in the gastrointestinal tract. Life-threatening bleeding into the head or in the area behind the lower abdomen may also occur. Evaluation by a physician is imperative.

• Vitamin K deficiency: Vitamin K deficiency is rare in adults but may lead to defective blood clotting and increased bleeding, as well as osteoporosis. People at risk for developing vitamin K deficiency include those with chronic malnutrition (including those with alcohol dependency) or conditions that limit absorption of dietary vitamins, such as biliary obstruction, celiac disease or sprue, ulcerative colitis, regional enteritis, cystic fibrosis, short bowel syndrome, or intestinal resection (particularly of the terminal ileum, where fat-soluble vitamins are absorbed). In addition, some drugs may reduce vitamin K levels by altering liver function or by killing intestinal flora (normal intestinal bacteria) that make vitamin K (for example, antibiotics, salicylates, antiseizure medications, and some sulfa drugs). Evaluation by a physician should be sought.

• Warfarin reversal (elevated INR/pre-procedure): Warfarin (Coumadin®) is a blood-thinning drug that inhibits vitamin K-dependent clotting factors. Warfarin is prescribed for people with various conditions, such as atrial fibrillation, artificial heart valves, or clotting disorders. Usually, blood tests are done regularly to evaluate the extent of blood thinning, using a test for prothrombin time (PT) or international normalized ratio (INR). The range for the PT or INR depends on the condition being treated. The PT or INR may become elevated for many reasons and sometimes becomes dangerously high and increases the risk of serious bleeding. Patients taking warfarin should be aware of these potential causes, which include many drugs that interact with warfarin, liver disorders, or accidental warfarin overdose. Because the effects of warfarin on anticoagulation are usually delayed by several days, the PT or INR may not increase immediately at the time of overdose. If a person's blood becomes too "thin," management should be under strict medical supervision and may include oral or injected vitamin K to help reverse the effects of warfarin.

• Avoid if allergic to vitamin K. Injection into the muscle or vein should only be done by a healthcare professional. Many serious side effects have occurred after injection. Menadiol (type of vitamin K that is not available in the United States) should be avoided with glucose-6-phosphate dehydrogenase deficiency. Avoid if pregnant or if taking anticoagulants. The American Academy of Pediatrics recommends giving a single vitamin K1 injection into the muscle for all newborns to prevent vitamin K deficiency bleeding (VKDB). However, large amounts of vitamin K may cause serious side effects or death. Vitamin K is generally considered safe for breastfeeding mothers.

• Zinc: Zinc is an essential mineral that is necessary for the functioning of more than 300 different enzymes. It plays a vital role in many biological processes.

• Diarrhea (children): Multiple studies in developing countries found that zinc supplementation in malnourished children with acute diarrhea may reduce the severity and duration of diarrhea, especially in children with low zinc levels.

• Gastric ulcers: The healing process of gastric ulcers may be enhanced through treatment with zinc, although further studies will be needed to determine to what extent zinc may be beneficial for patients with this condition. Most studies have reported no or few side effects associated with its use.

• Sickle cell anemia (management): There is strong scientific evidence to suggest that zinc may help manage or reduce symptoms of sickle cell anemia. Most of these studies reported increased height, weight, immune system function, and testosterone levels and decreased numbers of crises and sickled cells following zinc treatment.

• Zinc deficiency: Strong evidence supports the use of zinc supplementation for zinc deficiency.

• Zinc is generally considered safe when taken at recommended dosages. Avoid zinc chloride, since studies have not been done on its safety or effectiveness. Avoid with kidney disease. Use cautiously if pregnant or breastfeeding.

• Good scientific evidence:

• Calcium: Calcium is the most abundant mineral in the human body. To treat calcium disorders, calcium is given in various chelated forms. Chelated calcium has been chemically bonded to another molecule. Calcium citrate is an example of such a preparation. Calcium may also be combined with other substances to form preparations such as calcium lactate, calcium gluconate, or calcium carbonate.

• Black widow spider bite: Calcium may be combined with antiserum, pain relievers, and muscle relaxants to relieve muscle cramping from a black widow spider bite. Treatment of a black widow spider bite should only be done under the supervision of a qualified healthcare professional.

• High blood potassium level: Calcium gluconate may help reduce the cardiac toxicity and abnormal heart rhythm associated with hyperkalemia (high blood potassium), provided the patient is not receiving digitalis drug therapy. Treatment of hyperkalemia should only be performed under supervision of a qualified healthcare professional.

• High blood pressure: Several studies have found that calcium may have blood pressure-lowering effects. These studies indicate that high calcium levels lead to sodium loss in the urine, and lowered parathyroid hormone (PTH) levels, both of which result in reducing blood pressure. However, one study found that these results did not hold true for middle-aged patients with mild-to-moderate high blood pressure with no known cause. In the DASH (Dietary Approaches to Stop Hypertension; a diet promoted by the National Heart, Lung and Blood Institute) study, three servings daily of calcium enriched low-fat dairy products reduced systolic and diastolic blood pressure. This research indicates that a calcium intake at recommended levels may be helpful in preventing and treating moderate hypertension. Treatment of high blood pressure should only be done under supervision of a qualified healthcare professional.

• Premenstrual syndrome (PMS): There is a correlation between lower dietary intake of calcium and PMS symptoms. Results of clinical trials suggest that calcium supplementation may decrease symptoms associated with PMS, such as depressed mood, water retention, and pain.

• Avoid if allergic to calcium or lactose. High doses (more than 1,000 milligrams in men and women aged 19-50 years, and more than 1,200 milligrams in individuals older than age 50) taken by mouth may cause kidney stones. Avoid with high levels of calcium in the blood or urine, high levels of parathyroid hormone, bone tumors, digitalis toxicity, ventricular fibrillation (uncoordinated contraction of ventricular cardiac muscle in the heart), kidney stones, kidney disease, kidney failure, high serum phosphate levels, or sarcoidosis (nodule formation in the liver, lymph glands, lungs, and salivary glands). Calcium supplements made from dolomite (sedimentary rock and mineral composed of calcium magnesium carbonate), oyster shells, or bone meal may contain unacceptable levels of lead. Use cautiously in those with low levels of stomach acid (achlorhydria) or irregular heartbeat. Calcium appears to be safe in pregnant or breastfeeding women when used at recommended doses.

• Chromium Chromium is an essential mineral required by humans in relatively small amounts. Foods and beverages containing chromium include broccoli, grape juice, whole-wheat breads, potatoes, garlic, basil, beef, orange juice, turkey, red wine, apple, banana, and green beans.

• Hypoglycemia: Chromium has been studied in the treatment of diabetes and high blood sugar levels. It may also help regulate blood sugar in patients with low blood sugar disorders. More research is needed in this area to make a strong conclusion.

• Polycystic ovary syndrome (glucose tolerance): Chromium picolinate may help improve glucose tolerance in women with polycystic ovary syndrome. However, chromium does not appear to alter hormones. Additional research is needed to confirm these findings.

• Trivalent chromium appears to be safe, because side effects are rare or uncommon. However, hexavalent chromium may be poisonous (toxic). Avoid if allergic to chromium, chromate, or leather. Use cautiously with diabetes, liver problems, weakened immune systems (such as HIV/AIDS patients or organ transplant recipients), depression, Parkinson's disease, heart disease, and stroke. Use cautiously in patients who are taking medications for these conditions. Use cautiously if driving or operating machinery. Use cautiously if pregnant or breastfeeding.

• Folate (folic acid): Folate occurs naturally in food, and folic acid is the man-made form of this vitamin.

• Methotrexate toxicity: Folate supplementation is beneficial in patients being treated with long-term, low-dose methotrexate for rheumatoid arthritis (RA) or psoriasis. Psoriasis is a chronic, noninfectious skin disease characterized by red scaly patches on the skin. Development of folate deficiency is associated with increased risk of certain side effects, including gastrointestinal effects, stomatitis, alopecia (hair loss), abnormal liver function tests, myelosuppression, megaloblastic anemia, and increased homocysteine levels, the last of which is associated with heart disease. People who have experienced side effects may need to continue taking folic acid for the duration of methotrexate therapy. Patients receiving methotrexate for cancer should avoid folic acid supplements, unless recommended by their oncologists. There is some evidence that folic acid supplements reduce the efficacy of methotrexate in the treatment of acute lymphoblastic leukemia, and theoretically they could reduce its efficacy in the treatment of other cancers.

• Avoid if allergic to folate or any of the product ingredients. It is recommended that pregnant women consume 600 micrograms daily in order to reduce the risk of fetal defects. Folate is likely safe if breastfeeding if consumed at the recommended dietary allowance (RDA) of 500 micrograms daily.

• Iodine: Iodine is an element that the human body needs to make thyroid hormones.

• Bacterial conjunctivitis: Povidone-iodine solutions have been used in the management of childhood bacterial conjunctivitis and may be as effective as other antibacterial solutions such as neomycin-polymyxin B-gramicidin. This is not an effective treatment for viral conjunctivitis. Medical supervision is recommended.

• Graves' disease (adjunct iodine/iodides): Graves' disease is an immune-mediated disorder that causes hyperthyroidism. Iodide preparations, such as strong iodine solution (Lugol solution), potassium iodide (SSKI), and iodinated radiographic contrast agents (sodium ipodate), may be used to suppress thyroid hormone release from the thyroid. Patients undergoing thyroid surgery are commonly treated preoperatively with antithyroid drugs to achieve a euthyroid state, then SSKI.

• Hearing loss (iodine deficiency): Auditory disturbances may be present in iodine-deficient children, and continuous iodine supplementation may improve the auditory thresholds.

• Ocular surgery infection prevention/cataract surgery antisepsis: Topical iodine solutions, such as povidone-iodine, are used preoperatively to sterilize prior to ophthalmologic procedures. For example, povidone-iodine solution has been studied and used preoperatively for cataract surgery antisepsis.

• Ophthalmia neonatorum prevention: Ophthalmia neonatorum is defined as bacterial conjunctivitis with eye discharge that occurs during the first month of life. Although this condition is now uncommon in industrialized nations, it remains a problem in developing regions, with an incidence as high as 20-30%. Cases of blindness due to this condition have been reported in Africa each year. Povidone-iodine ophthalmic solution appears to have broad-spectrum activity against bacteria and is less expensive than many antibiotics.

• Oral mucositis: There is limited research suggesting that iodine mouth rinses may decrease the severity of mucositis (inflammation of the mucous membranes) in the mouth resulting from cancer chemotherapy or radiation therapy. The management of mucositis should be discussed with the cancer care team.

• Thyrotoxicosis/thyroid storm (adjunct iodides): Hyperthyroid crisis (thyroid storm) is a medical emergency caused by the excessive release of thyroid hormones. Initial management of this condition involves inhibition of thyroid function with thioamide drugs such as propylthiouracil or methimazole. Iodides (such as potassium iodide) may then be administered to block the release of thyroid hormone but should only be given one hour after thioamides to assure that the iodide is not used by the thyroid to make more thyroid hormone and worsen symptoms. Caution is warranted because iodide preparations carry a risk of causing serum sickness (a reaction similar to allergy). Iodides should not be used for long-term treatment of thyrotoxicosis.

• Supplements should be taken under the supervision of a healthcare provider. There have been reports of severe and even fatal reactions to iodine. Avoid iodine-based products if allergic to iodine. Do not use for more than 14 days. Lugol solution and saturated solution of potassium iodide (SSKI, PIMA) should be avoided in patients with pulmonary edema, bronchitis, known tuberculosis, or hyperkalemia (above-normal potassium blood levels), because of potential side effects from excess iodine or potassium. Use cautiously when applying to the skin, because iodine may irritate or burn tissues. Use sodium iodide cautiously in those with kidney failure or gastrointestinal obstruction (blockage in the stomach and intestine). Iodine is safe in recommended doses for pregnant or breastfeeding women. Avoid povidone-iodine (a widely used antiseptic preparation of polyvinylpyrrolidone and iodine) for perianal (around the anus) preparation during delivery. Avoid povidone-iodine for preventing infection after delivery.

• Iron: Iron is an essential mineral.

• ACE inhibitor-associated cough: Taking iron by mouth seems to inhibit cough associated with angiotensin-converting enzyme (ACE) inhibitors, such as captopril (Capoten®), enalapril (Vasotec®), and lisinopril (Prinivil®, Zestril®).

• Preventing iron deficiency in menstruating women: Iron supplementation has been shown to improve iron status in menstruating women.

• Prevention of iron deficiency anemia in pregnancy: Iron supplements have been shown to help prevent iron deficiency anemia in pregnant women. Anemia in pregnant women is associated with adverse outcomes such as low birthweight, premature birth, and death of the mother. Screening by a qualified healthcare provider is needed.

• Allergic reactions to iron are unlikely. Avoid if allergic to products containing iron. Avoid excessive intake. Avoid iron supplements with blood disorders that require frequent blood transfusions. Use iron supplement cautiously with a history of kidney disease, intestinal disease, heart disease, peptic ulcer disease, enteritis (inflammation of the small intestine), colitis (inflammation of the colon, or large intestine), pancreatitis (inflammation of the pancreas), hepatitis (inflammation of the liver), or alcoholism. Use cautiously if older than 55 years old, as use may increase risk of heart disease. Pregnant or breastfeeding women should consult their healthcare professionals before beginning iron supplementation.

• Magnesium: Magnesium is a mineral nutrient. Good sources of dietary magnesium include green vegetables (such as spinach), whole grains, nuts, legumes, and halibut.

• Arrhythmia (irregular heartbeat): Irregular heartbeats are the most common complications after heart surgery. Magnesium injected into the vein has been reported to reduce irregular heartbeats (e.g., atrial fibrillation and cardiac arrhythmias). However, it was not found to affect the length of hospital stay, incidence of heart attack, or death rate.

• Asthma: Asthma frequently worsens over time. Asthma attacks range from mild to severe. Magnesium sulfate is one of many treatment options available for acute asthma attacks. Magnesium sulfate administered in the vein or inhaled using a nebulizer in combination with other asthma therapies may help treat acute asthma attacks, particularly in children with severe symptoms. However, magnesium is not as effective for mild-to-moderate attacks.

• Diabetes (Type 2): Type 2 diabetes is often preventable through diet and exercise. Obesity is a major factor in its development. Magnesium taken by mouth has been reported to reduce the risk of developing type 2 diabetes and to improve blood sugar control in type 2 diabetic patients. Other than a modest decrease in blood pressure, magnesium supplementation was found to have only a small impact on other important endpoints associated with diabetes complications.

• Hearing loss: Magnesium treatment has been shown to reduce temporary and permanent hearing loss caused by noise. However, it is unclear how magnesium may work.

• Avoid in patients with known allergy to magnesium or other products found in magnesium supplements. Magnesium allergy is reported to be extremely rare. Magnesium may cause stomach irritation, nausea, vomiting, diarrhea, decreased skeletal muscle tone, and decreased estrogen levels. High blood levels of magnesium (hypermagnesemia) may cause thirst; drowsiness; low blood pressure; delirium; coma; heart, muscle, and respiratory disorders; and death. Toxic levels of magnesium may cause depression of the central nervous system. Magnesium may increase the risk of bleeding, and caution is advised in patients with bleeding disorders or those who are taking drugs, such as warfarin (Coumadin®), that may increase the risk of bleeding. Dosing adjustments may be necessary. Avoid in patients with kidney disorders and atrioventricular heart block (when the electric signal from the heart's upper to lower chambers is not being sent correctly). Avoid using magnesium as a laxative in patients with stomach disorders. Patients taking antidiabetic agents, blood pressure-lowering agents, or antibiotics (such as fluoroquinolones and cephalosporins) should use magnesium cautiously. Side effects appear to be uncommon with therapeutic doses of magnesium in infants or women who are pregnant or breastfeeding. According to the National Institute of Health's Lactation and Toxicology Database (LactMed), magnesium sulfate and magnesium hydroxide are acceptable to use during breastfeeding.

• Niacin: Niacin (Vitamin B3) is a B-complex vitamin found in many foods, such as liver, poultry, fish, nuts, and dried beans.

• Atherosclerosis (niacin): Niacin decreases blood levels of cholesterol and lipoprotein (a), which may reduce the risk of atherosclerosis ("hardening" of the arteries). However, niacin may also increase homocysteine levels, which may have the opposite effect. Overall, the scientific evidence supports the use of niacin in combination with other drugs (but not alone) to decrease cholesterol and slow the process of atherosclerosis. More research is needed in this area before a firm conclusion can be drawn.

• Prevention of a second heart attack(niacin): Numerous studies have looked at the effects of niacin, alone and in combination with other drugs, for the prevention of heart disease and fatal heart attacks. Overall, this research suggests benefits of niacin, especially when combined with other cholesterol-lowering drugs.

• Avoid niacin (vitamin B3) if allergic to niacin or niacinamide. Avoid with a history of liver disease, irregular heartbeat, heart disease, blood clotting, bleeding disorders, asthma, anxiety, panic attacks, thyroid disorders, stomach ulcers, gout, or diabetes. Avoid if pregnant or breastfeeding.

• Selenium:Selenium is a trace mineral found in soil, water, and some foods. It is an essential element in several metabolic pathways.

• Antioxidant: Selenium is a component of glutathione peroxidase, an enzyme that has antioxidantactivity and demonstrates antioxidant properties in humans. Long-term clinical benefits remain controversial.

• Keshan disease: Keshan disease is a cardiomyopathy (heart disease) restricted to areas of China where people have an extremely low selenium status. Prophylactic administration of sodium selenite has been shown to significantly decrease the incidence of this disorder. Organic forms of selenium (such as selenized yeast or Se-yeast) may have better bioavailability than selenite and thus may be better preventive treatments for Keshan disease. Selenium is used to treat and prevent selenium deficiency (for example, in those with HIV or using feeding tubes).

• Prostate cancer prevention: Initial evidence has suggested that selenium supplementation may reduce the risk of prostate cancer in men with normal baseline PSA (prostate-specific antigen) levels and low selenium blood levels. It is not known if selenium is helpful in men with a history of prostate cancer. It appears that selenium may not be beneficial in those with elevated PSA levels or with normal or high selenium levels. It remains unclear whether men at risk (or all men) should have their serum selenium values measured. There is evidence that low selenium levels are associated with an increased risk of prostate cancer, and several mechanisms for the beneficial effects of selenium supplementation have been suggested.

• Hypersensitivity to selenium is unlikely. Avoid individuals with a known allergy or hypersensitivity to products containing selenium. Selenium deficiency may occur in areas where the soil content of selenium is low. Deficiency may affect thyroid function and cause conditions such as Keshan disease. Selenium deficiency is also commonly seen in patients on total parenteral nutrition (TPN) as their sole source of nutrition. Gastrointestinal disorders may decrease the absorption of selenium, resulting in depletion or deficiency.

• Thiamin (thiamine), vitamin B1: Thiamin (thiamine), also called vitamin B1, is a water-soluble vitamin.

• Acute alcohol withdrawal: Patients with chronic alcoholism or alcohol withdrawal are at risk of thiamin deficiency and its associated complications and should be administered thiamin.

• Total parenteral nutrition (TPN): Total parenteral nutrition is the process of feeding a patient without passing the nutrients through the gut. Thiamin should be added to TPN formulations for patients who are unable to receive thiamin through other sources (such as a multivitamin) for longer than seven days.

• Thiamin is generally considered safe and relatively nontoxic, even at high doses. Avoid if allergic or hypersensitive to thiamin. Thiamin appears safe if pregnant or breastfeeding when taken at the recommended dietary allowance of 1.4 milligrams daily.

• Vitamin A: Vitamin A is a fat-soluble vitamin that is needed for vision.

• Malaria (supportive agent): Limited research suggests that vitamin A may reduce fever, sickness, and parasite blood levels in patients with malaria (Plasmodium falciparum infection). However, there is a lack of evidence suggesting that vitamin A is equivalent or superior to well-established drug therapies used for the prevention or treatment of malaria. People who have malaria or live or travel in areas where malaria is prevalent should speak with their physicians about appropriate measures.

• Retinitis pigmentosa: The genetic disorder retinitis pigmentosa reduces night vision. Early symptoms include night blindness and progressive loss of vision. Based on recent findings, the palmitate form of vitamin A has been recommended in patients with retinitis pigmentosa.

• Avoid if allergic to vitamin A. intake levels. Use cautiously in those with liver disease or alcoholism. Smokers who consume alcohol and beta-carotene may have an increased risk of developing lung cancer or heart disease. Vitamin A appears safe in pregnant women if taken in recommended doses. Use cautiously if breastfeeding, because the benefits or dangers to nursing infants are not clearly established.

• Vitamin C (ascorbic acid): Vitamin C (ascorbic acid) is a vitamin that the body needs to form collagen in bones, cartilage, muscle, and blood vessels.

• Common cold prevention (extreme environments): Scientific studies generally suggest that vitamin C does not prevent the onset of cold symptoms. However, in a subset of studies in people living in extreme climates or under extraordinary conditions, including soldiers taking part in subarctic exercises, skiers, and marathon runners, vitamin C significantly reduced the risk of developing colds by approximately 50%. This area merits more study and may be of particular interest to elite athletes or military personnel.

• Iron absorption enhancement: Based on scientific research, vitamin C appears to improve absorption of iron taken by mouth. Vitamin C taken together with iron dietary supplements may aid in the absorption of iron.

• Urinary tract infection (during pregnancy): Vitamin C may decrease the risk of developing urinary tract infections during pregnancy. Further research is needed to confirm these findings.

• Vitamin C is generally considered safe in the amounts commonly found in foods. Vitamin C supplements are also generally considered safe in most individuals if taken in recommended doses. Avoid high doses of vitamin C with glucose-6-phosphate dehydrogenase (G6PD) deficiency, kidney disorders or stones, cirrhosis (scarring and poor function of the liver as a result of chronic liver disease), gout, or paroxysmal nocturnal hemoglobinuria (a bleeding disorder). Vitamin C intake from food is generally considered safe if pregnant or breastfeeding. It is not clear if vitamin C supplements in doses higher than dietary reference intake recommendations are safe for pregnant or breastfeeding women. Vitamin C is naturally found in breast milk.

• Vitamin D: Vitamin D is found in many foods, including fish, eggs, fortified milk, and cod liver oil. Vitamin D is made by human skin exposed to sunlight.

• Muscle weakness/pain: Vitamin D deficiency has been associated with muscle weakness and pain in both adults and children. Limited research has reported vitamin D deficiency in patients with low-back pain, and supplementation may reduce pain in many patients.

• Osteoporosis (general): Without sufficient vitamin D, inadequate calcium is absorbed and the resulting elevated parathyroid (PTH) secretion causes increased bone loss. This may weaken bones and increase the risk of fracture. Vitamin D supplementation has been shown to slow bone loss and reduce fracture, particularly when taken with calcium.

• Renal osteodystrophy: Renal osteodystrophy is a term that refers to all of the bone problems that occur in patients with chronic kidney disease. Oral calcifediol or ergocalciferol may help manage hypocalcemia (low blood calcium) and prevent renal osteodystrophy in people with chronic kidney disease undergoing dialysis.

• Avoid if allergic or hypersensitive to vitamin D or any of its components. Vitamin D is generally well tolerated in recommended doses. Doses higher than recommended may cause toxic effects. Individuals with hyperparathyroidism (overactive thyroid), kidney disease, sarcoidosis (nodule formation in the liver, lymph glands, lungs, and salivary glands), tuberculosis, or histoplasmosis (a fungal infection that affects the lungs) have a higher risk of experiencing toxic effects. Vitamin D is generally considered safe for pregnant women. It may be necessary to give infants vitamin D supplements along with breast milk.

• Zinc: Zinc is an essential mineral that is necessary for the functioning of more than 300 different enzymes. It plays a vital role in many biological processes.

• Acne vulgaris: Based on high-quality studies, topical or oral use of zinc seems to be a safe and effective treatment for acne. However, some studies have reported no or negative effects from zinc. Additionally, many studies used combination treatments.

• Attention-deficit hyperactivity disorder (ADHD): Early studies suggest a possible correlation between low serum free fatty acids and zinc serum levels in children with ADHD. Additional studies found that zinc supplements reduced hyperactive, impulsive, and impaired socialization symptoms, but did not reduce attention-deficiency symptoms. Zinc supplementation may be a more effective treatment for older children with higher body mass index (BMI) scores.

• Down syndrome: In several studies, zinc supplements seemed to counteract hypothyroidism and slightly reduce the number of infections in children with Down syndrome. However, zinc did not seem to improve depressed immune systems.

• Fungal infections (scalp): Human trials suggests that zinc pyrithione shampoo may help treat tinea versicolor fungal infections of the scalp. Additional research is needed.

• Herpes simplex virus: Low-quality studies have been conducted to assess the effects of zinc (topical or taken by mouth) on herpes type I or II. Several of these studies used combination treatments or permitted the continued use of other medications, so the exact role of zinc in those studies is unclear. However, the positive results obtained in most trials suggest that zinc may represent a safe and effective alternative treatment for herpes type I and II and should encourage further research into the topic using well-designed studies.

• High cholesterol: Zinc may improve blood cholesterol levels in hemodialysis patients. There is some evidence that zinc may improve cholesterol ratio of HDL ("good") cholesterol versus LDL ("bad") cholesterol.

• Immune function: Zinc appears to be an essential trace element for the immune system, but research on the effect of zinc supplementation on immune function is scant and mostly focuses on patients with specific diseases. Zinc gluconate appears to have beneficial effects on immune cells. There are relatively few studies that examine zinc levels and the effects of zinc supplementation on the health of the elderly population.

• Plaque/gingivitis: A few studies have reported significant reduction in plaque accumulation following treatment with zinc rinses and dentifrices. Preliminary research suggests that zinc citrate dentifrice may reduce the severity and occurrence of supragingival calculus formation.

• Wilson's disease: Wilson's disease is an inherited disorder of copper metabolism characterized by a failure of the liver to excrete copper. Early research suggests that zinc treatment may be effective in the management of Wilson's disease.

• Zinc is generally considered safe when taken at recommended dosages. Avoid zinc chloride since studies have not been done on its safety or effectiveness. Avoid with kidney disease. Use cautiously if pregnant or breastfeeding.

• Unclear or conflicting scientific evidence:

• Biotin: Biotin is a water-soluble vitamin that is needed for carbohydrate and protein metabolism.

• Brittle fingernails: Biotin has been suggested as a treatment for brittle fingernails, particularly in women. There is insufficient scientific evidence to form a clear conclusion.

• Cardiovascular disease risk (in diabetics): A combination of biotin and chromium may help lower cholesterol and decrease the risk of developing clogged arteries (atherosclerosis) in diabetics. However, other research of biotin alone found that biotin did not affect cholesterol, glucose, or insulin levels but did decrease the levels of triglycerides, or fats, in the blood. More research with biotin alone is needed.

• Diabetes mellitus (type 2): In early research, biotin has been reported to decrease insulin resistance and improve glucose tolerance, which are both properties that may be beneficial in patients with type 2 (adult-onset) diabetes. Other research suggests that a combination of biotin and chromium may help improve blood sugar control. However, there is not enough human evidence to form a clear conclusion in this area.

• Hepatitis (in alcoholics): Antioxidant therapy with biotin, vitamins A-E, selenium, zinc, manganese, copper, magnesium, folic acid, and Coenzyme Q10 did not improve survival rates in alcoholics with hepatitis. More research with biotin alone is needed.

• Pregnancy supplementation: Marginal biotin deficiency has been found to commonly occur during pregnancy. Biotin supplementation during pregnancy is not currently standard practice, and prenatal vitamins generally do not contain biotin. However, individual patients may be considered for biotin supplementation by healthcare practitioners on a case-by-case basis. Additional study is needed in this area.

• Total parenteral nutrition: Intravenous feeding solutions (TPN) should contain biotin in order to avoid biotin deficiency in patients for whom TPN is the sole source of nutrition. More study is needed in this area to make a firm conclusion.

• Avoid if hypersensitive to constituents of biotin supplements.

• Calcium: Calcium is the most abundant mineral in the human body. To treat calcium disorders, calcium is given in various chelated forms. Chelated calcium has been chemically bonded to another molecule. Calcium citrate is an example of such a preparation. Calcium may also be combined with other substances to form preparations such as calcium lactate, calcium gluconate, or calcium carbonate.

• Bone stress injury prevention: Calcium supplementation above the normal daily dietary intake did not reduce stress fractures in men. Thus, calcium supplementation may not be effective in preventing stress fractures. Further studies are needed to confirm or refute these initial findings.

• Colorectal cancer: Colorectal cancer is the most common gastrointestinal cancer and is one of the top causes of cancer deaths in the United States. Colorectal cancer results from a combination of genetic and environmental factors. The degree to which these two factors influence colon cancer risk in individuals varies. Most large prospective studies have found increased calcium intake to be only weakly associated with a decreased risk of colorectal cancer. Further studies are needed to verify these results. Treatment of colorectal cancer should only be done under the supervision of a qualified healthcare professional.

• Growth (mineral metabolism in very-low-birthweight infants): Growth of very-low-birthweight infants correlates with calcium intake and retention in the body. Commonly used human milk fortifiers may have inadequate levels of calcium for infants of very low birthweight. Bone mineralization is also lower in very-low-birthweight infants at their theoretical term than in infants born at term. Use of an infant formula containing higher levels of calcium has been suggested to improve bone mineralization in these infants.

• High blood pressure (pregnancy-induced): For the general population, meeting current recommendations for calcium intake during pregnancy may help prevent pregnancy-induced high blood pressure (PIH). Further research is required to determine whether women at high risk for PIH would benefit from calcium supplementation above the current recommendations. Treatment of PIH should only be done under supervision of a qualified healthcare professional.

• Hyperparathyroidism (secondary): Hemodialysis, used by patients experiencing kidney failure, is a laboratory procedure in which waste from the blood is removed by a dialysis machine. In patients treated with hemodialysis, calcium supplementation may reduce secondary hyperparathyroidism (high blood levels of parathyroid hormone due to another medical condition or treatment). Treatment of hyperparathyroidism should only be done under the supervision of a qualified healthcare professional.

• Lead toxicity (acute symptom management): A lead chelating treatment using calcium has been suggested to reduce blood levels of lead in cases of lead toxicity. Reduced symptoms have been observed in most, but not all, patient case reports and case histories. Adequate calcium intake appears to be protective against lead toxicity. Treatment of lead toxicity should only be done under the supervision of a qualified healthcare professional.

• Osteomalacia/rickets: Rickets and osteomalacia (bone softening) are commonly thought of as diseases due to vitamin D deficiency. However, calcium deficiency may also be another cause in sunny areas of the world where vitamin D deficiency would not be expected. Calcium gluconate is used as an adjuvant in the treatment of rickets and osteomalacia, as well as a single therapeutic agent in non-vitamin D deficient rickets. Research continues into to the importance of calcium alone in the treatment and prevention of rickets and osteomalacia. Treatment of rickets and osteomalacia should only be done under the supervision of a qualified healthcare professional.

• Osteoporosis prevention (steroid-induced): Calcium supplementation in patients taking long-term, high-dose inhaled steroids for asthma may reduce bone loss due to steroid intake. Treatment with the prescription drug pamidronate with calcium has been shown to be superior to calcium alone in the prevention of corticosteroid-induced osteoporosis. Inhaled steroids have been reported to disturb normal bone metabolism, and they are associated with a decrease in bone mineral density. Results suggest that long-term administration of high-dose inhaled steroid induces bone loss that is preventable with calcium supplementation with or without the prescription drug etidronate. Long-term studies involving more patients are needed to confirm these preliminary findings.

• Prostate cancer (increased risk): The lack of agreement among these studies suggests complex interactions among risk factors for prostate cancer. Until the relationship between calcium and prostate cancer is clarified, it is reasonable for men to consume amounts of calcium recommended by the Food and Nutrition Board of the Institute of Medicine. Treatment of prostate cancer should only be under the supervision of a qualified healthcare professional.

• Weight loss: Diets high in calcium have been associated with a reduced incidence of being overweight or obese in several studies. Although more research is needed to understand the relationships between calcium intake and body fat, these findings emphasize the importance of maintaining an adequate calcium intake while attempting to diet or lose weight.

• Avoid if allergic to calcium or lactose. High doses (more than 1,000 milligrams in men and women aged 19-50 years, and more than 1,200 milligrams in individuals older than age 50) taken by mouth may cause kidney stones. Avoid with high levels of calcium in the blood or urine, high levels of parathyroid hormone, bone tumors, digitalis toxicity, ventricular fibrillation (uncoordinated contraction of ventricular cardiac muscle in the heart), kidney stones, kidney disease, kidney failure, high serum phosphate levels, or sarcoidosis (nodule formation in the liver, lymph glands, lungs, and salivary glands). Calcium supplements made from dolomite (sedimentary rock and mineral composed of calcium magnesium carbonate), oyster shells, or bone meal may contain unacceptable levels of lead. Use cautiously in those with low levels of stomach acid (achlorhydria) or irregular heartbeat. Calcium appears to be safe in pregnant or breastfeeding women when used at recommended doses.

• Chromium Chromium is an essential mineral required by humans in relatively small amounts. Foods and beverages containing chromium include broccoli, grape juice, whole-wheat breads, potatoes, garlic, basil, beef, orange juice, turkey, red wine, apple, banana, and green beans.

• Bipolar disorder: There is insufficient available evidence to recommend chromium for bipolar disorder.

• Bone loss (postmenopausal women): There is a lack of evidence for or against the use of chromium for the treatment of bone resorption, or bone loss, in postmenopausal women.

• Cardiovascular disease: An association has been made between high chromium levels in the blood and a lower risk of coronary artery disease (clogged arteries in the heart). Chromium should be used cautiously, however, due to possible increases in blood pressure. Better studies are needed to provide more definitive answers.

• Cognitive function: Early research suggests that chromium picolinate may help improve cognitive function in the elderly. Further study is needed in this area.

• Depression: Early studies show that chromium picolinate may improve symptoms of depression in people with a form of depression known as atypical depression. Further research is needed before a conclusion can be made.

• Diabetes mellitus: Chromium has been studied for its potential to treat blood sugar abnormalities in people with types 1 and 2 diabetes, as well as at-risk populations. Some studies suggest that taking chromium by mouth may lower blood sugar levels, whereas other studies show no effects. Some research reports that chromium may improve symptoms of hypoglycemia (low blood sugar). Better studies are needed to provide more definitive answers.

• High cholesterol: Studies show conflicting results in the use of chromium to treat high cholesterol. A few studies show that chromium may lower cholesterol, but other studies show no effect. Many natural medicine experts and textbooks do not recommend chromium for treating high cholesterol over more proven therapies.

• Immunosuppression: Chromium, in combination with copper, may have potential suppressive effects on immune function. Further research is needed to confirm these results.

• Parkinson's disease: Chromium has been studied for its protective benefits in Parkinson's disease and is included in antioxidant multivitamins. However, there is lack of scientific evidence in humans in this area. Additional study is needed.

• Schizophrenia: Early study shows a lack of effect of supplemental chromium on mental state and body weight in people with schizophrenia. Additional study is needed.

• Trivalent chromium appears to be safe, because side effects are rare or uncommon. However, hexavalent chromium may be poisonous (toxic). Avoid if allergic to chromium, chromate, or leather. Use cautiously with diabetes, liver problems, weakened immune systems (such as HIV/AIDS patients or organ transplant recipients), depression, Parkinson's disease, heart disease, and stroke. Use cautiously in patients who are taking medications for these conditions. Use cautiously if driving or operating machinery. Use cautiously if pregnant or breastfeeding.

• Copper: Copper is a mineral occurring naturally in many foods, including vegetables, legumes, nuts, grains, fruits, shellfish, avocado, beef, and animal organs.

• Age-related macular degeneration: Sufficient scientific evidence to determine if copper plays a role in age-related macular degeneration is lacking.

• Alzheimer's disease prevention: Conflicting study results have reported that copper intake may either increase or decrease the risk of developing Alzheimer's disease. Additional research is needed before a conclusion can be made.

• Arthritis: The use of copper bracelets in arthritis treatment has a long history of traditional use, with many anecdotal reports of effectiveness. There are research reports suggesting that copper salicylate may reduce arthritis symptoms more effectively than either copper or aspirin alone. Further study is needed before a firm conclusion can be made.

• Cancer: Preliminary research reports indicate that lowering copper levels may theoretically arrest cancer progression by inhibiting blood vessel growth (angiogenesis). Copper intake has not been identified as a risk factor for the development or progression of cancer.

• Cardiovascular disease prevention/atherosclerosis: The effects of copper intake or blood copper levels on cholesterol, atherosclerosis, or coronary artery disease remain unclear. Results of human studies are mixed. Further research is needed in this area.

• Childhood growth promotion: Severe copper deficiency may retard growth. Adequate intake of micronutrients including copper and other vitamins may promote growth as measured by increases in length/height.

• Dental conditions (protecting enamel and plaque prevention): Laboratory studies have shown that copper may help protect tooth enamel (the outer layer of the teeth). However, early human research suggests that copper may not be effective.

• Immune system function: Copper is involved in immune cell development and immune function in the body. Severe copper deficiency appears to have adverse effects on immune function, although the exact mechanism is unclear.

• Malnutrition (marasmus): Copper deficiency may occur with marasmus, and supplementation with copper may play a role in the nutritional treatment of infants with this condition. Infants with marasmus should be managed by a qualified healthcare professional.

• Menkes kinky-hair disease: Menkes kinky-hair disease is a rare disorder of copper transport and absorption. Copper supplementation may be helpful in this disease, although further research is necessary before a clear conclusion can be made.

• Metabolic disorders (trimethylaminuria): Trimethylaminuria (TMAU) is a metabolic disorder characterized by the inability to oxidize and convert dietary-derived trimethylamine (TMA) to trimethylamine N-oxide (TMAO). Preliminary evidence suggests that the use of copper chlorophyllin results in a reduced urinary-free TMA concentration and normalization of TMAO. Further research is required in this field before a strong conclusion can be made.

• Osteoporosis/osteopenia: Osteopenia and other bone development abnormalities related to copper deficiency may occur in copper-deficient low-birthweight infants and young children. Copper supplementation may be helpful in the treatment and prevention of osteoporosis, but results of initial studies in humans are conflicting. The effects of copper deficiency or copper supplementation on bone metabolism and age-related osteoporosis require further research before clear conclusions can be drawn.

• Schizophrenia: Some studies of schizophrenic patients have reported high blood copper levels with low urinary copper (suggesting that copper is being retained) and low blood zinc levels. In some of these cases, zinc was observed to be helpful as an antianxiety agent. The role of copper supplementation is not clear.

• Sideroblastic anemia: Copper deficiency is one of the causes of sideroblastic anemia. The possibility of copper deficiency should be considered when evaluating this condition, particularly when the anemia is unresponsive to iron therapy alone. Sideroblastic anemia appears to be caused by defective iron mobilization due to decreased ceruloplasmin activity.

• Skin rejuvenation: Copper has been used to reduce wrinkles and improve skin appearance following laser skin resurfacing. Currently, there is not enough scientific evidence to make conclusions in this area.

• Systemic lupus erythematosus (SLE): A preliminary study suggests that copper offers no benefit to individuals with SLE. Further research is required before conclusions can be made.

• Avoid if allergic to copper. Avoid use of copper supplements when recovering from diarrhea, because excess copper may worsen symptoms. Avoid with hypercupremia (excess copper in the blood). Avoid with genetic disorders affecting copper metabolism (e.g., Wilson's disease, Indian childhood cirrhosis, or idiopathic copper toxicosis). Avoid in those with HIV or AIDS. Use caution when using tap water that contains more than 6 milligrams of copper per liter to prepare food or drinks. Use cautiously in those with anemia, joint pain, or muscle pain, or those at risk for selenium deficiency. Use cautiously if taking birth control pills.

• Folate (folic acid): Folate occurs naturally in food, and folic acid is the man-made form of this vitamin.

• Alzheimer's disease: Preliminary evidence indicates that low folate concentrations may be related to Alzheimer's disease. Well-designed clinical trials of folate supplementation are needed before a conclusion can be drawn.

• Arsenic poisoning (arsenic-induced illnesses): Folate may lower blood arsenic concentrations and thereby contribute to the prevention of arsenic-induced illnesses. Additional research is needed in this area.

• Cancer: Preliminary evidence surrounding folate use seems promising for decreasing the risk of breast, cervical, pancreatic, and gastrointestinal cancer. However, currently there is insufficient evidence available to determine if folate supplementation is effective for any type of cancer prevention or treatment. A qualified healthcare provider should be consulted in this regard.

• Chronic fatigue syndrome: Some patients with chronic fatigue syndrome (CFS) also have decreased folic acid levels. Daily injections of a combination of folic acid, bovine liver extract, and vitamin B12 for three weeks lacked benefit for CFS in early study.

• Cognitive function: Combined B vitamin supplementation (including folate) did not delay cognitive decline among women with cardiovascular disease or risk factors for the disease. The possible cognitive benefits of supplementation among women with a low dietary intake of B vitamins warrant further study.

• Coronary artery disease (prevention of nitrate tolerance): Folic acid may prevent nitroglycerin-induced nitrate tolerance and cross tolerance to endothelial nitric oxide, which plays a role in blood pressure control. These conditions need to be treated by a qualified healthcare provider.

• Depression: Folate deficiency has been found among people with depression and has been linked to poor response to antidepressant treatment. Folic acid supplements have been used for enhancing treatment response to antidepressants. Limited clinical research suggests that folic acid is not effective as a replacement for conventional antidepressant therapy. Depression should be treated by a qualified healthcare provider.

• Folate deficiency in alcoholics: Folate deficiency has been observed in alcoholics. Alcohol interferes with the absorption of folate and increases excretion of folate by the kidney. Many alcohol abusers have poor-quality diets that do not provide the recommended intake of folate. Increasing folate intake through diet, or folic acid intake through fortified foods or supplements, may be beneficial to the health of alcoholics.

• Hearing loss (age-associated hearing decline): Folic acid supplementation slowed the decline in hearing of speech frequencies associated with aging in a population from a country without folic acid fortification of food. The effect requires confirmation, especially in populations from countries with folic acid fortification programs.

• High blood pressure associated with pregnancy: In women with high blood pressure during pregnancy, a combination therapy containing folate made it possible to maintain pregnancy until delivery. This was beneficial for both the mother and child. More well-designed studies are needed to examine the role of folate monotherapy in this condition.

• High blood sugar/glucose intolerance: In individuals with high blood sugar, folic acid in combination with enalapril, a drug used to treat high blood pressure, resulted in a greater reduction in blood glucose levels compared to enalapril alone. More trials are needed before a conclusion can be made.

• Phenytoin-induced gingival hyperplasia: Early evidence suggests that applying folic acid to the gums may inhibit gingival hyperplasia (overgrowth of gum tissue) secondary to phenytoin therapy. Phenytoin is an anticonvulsant drug used to treat epilepsy. However, more research is needed in this area.

• Pregnancy-related gingivitis: Based on preliminary data, applying folic acid to the gums may improve gingivitis in pregnant women. Well-designed clinical trials are needed to confirm these results.

• Stroke: Study results are mixed for the use of folate in stroke patients. Further research is needed in this area before a strong conclusion can be made.

• Vascular disease/hyperhomocysteinemia: Elevated homocysteine levels may be a marker of vascular disease. Preliminary data suggest that folic acid lowers homocysteine levels and may reduce the risk of vascular disease (cardiac, peripheral, or cerebral). Large randomized controlled trials are needed before a firm conclusion can be drawn.

• Vitiligo: Based on preliminary data, folic acid and vitamin B12 may improve the symptoms of vitiligo, a skin condition in which loss of pigment occurs, resulting in white patches. Further research is needed to confirm these results.

• Avoid if allergic to folate or any of the product ingredients. It is recommended that pregnant women consume 600 micrograms daily in order to reduce the risk of birth defects. Folate is likely safe if breastfeeding if consumed at the recommended dietary allowance (RDA) of 500 micrograms daily.

• Iodine: Iodine is an element that the human body needs to make thyroid hormones.

• Bladder irrigation: Povidone-iodine bladder irrigation has been suggested prior to catheter removal, or prior to prostatectomy (prostate gland removal) surgery, to reduce the risk of infection. There is limited research in this area.

• Bleeding: Early research suggests that povidone-iodine may control bleeding better than saline. Additional research is needed before a strong conclusion can be made.

• Bowel irrigation: Povidone-iodine irrigation before large bowel resection has been suggested as a sterilization technique.

• Cancer: The potential role of nonradioactive iodine in cancer care remains unknown. Antioxidant and antitumor effects have been proposed, based on laboratory research. In contrast, some scientists have asserted that tumors may uptake more iodine than normal tissues. It has been suggested that high rates of gastric (stomach) cancer or low rates of breast cancer in coastal Japan may be due to high iodine intake, although this has not been demonstrated scientifically. Povidone-iodine solutions have been used as a part of alternative cancer regimens, such as the Hoxsey formula. Preliminary study has also indicated povidone-iodine solution as a potential rectal washout for rectal cancer. Overall, no clear conclusion can be drawn based on the currently available evidence.

• Cognitive function: Iodine is required for the production of thyroid hormones, which are necessary for normal brain development and cognition. Early study suggested that iodized oil taken by mouth significantly improved performance on cognitive tests in 10-12 year-old school children. Further study is needed to confirm these results.

• Corpus vitreous degeneration: Topical administration of iodine eye drops may reduce corpus vitreous degeneration in the eye. Further study is needed to confirm these results.

• Goiter treatment: Iodine deficiency may cause goiter (hypertrophy of the thyroid gland). Other causes of goiter should be considered in patients with this condition, such as autoimmune thyroiditis, excess iodine, other hormonal disorders, radiation exposure, infectious causes, or inborn errors of metabolism. Although goiter due to low iodine intake is rare in developed countries, it may occur in regions with naturally low soil iodine levels. Initial management of goiter should involve a medical evaluation to identify the underlying cause and assessment of levels of thyroid hormones in the body. Treatment usually involves the administration of thyroid hormone, most commonly levothyroxine sodium (Synthroid®, Levoxyl®, Levothroid®). Iodine plays a role in goiter prevention, but not in acute management of this condition. Iodine deficiency should be corrected with supplementation.

• Lymphedema (filarial): Foot care with Betadine® may help in the management of lymphoedema that is the result of infection with parasitic worms.

• Molluscum contagiosum: Povidone-iodine has been suggested as a topical treatment for molluscum, a viral infection of the skin. There is limited research in this area.

• Oral intubation: Gargling with povidone-iodine before having a tube (such as a feeding tube) inserted through the mouth reduces the transport of bacteria into the trachea.

• Pelvic infection: In in vitro fertilization (IVF), vaginal douching, or rinsing, with aqueous povidone-iodine followed by normal flushing with saline immediately before collecting eggs seems effective in preventing the pelvic infection without affecting the outcome of IVF treatment.

• Periodontitis/gingivitis: Povidone-iodine mouthwash has been suggested to reduce levels of bacteria in the mouth in those with periodontitis (gum disease) or who have had oral surgery. Evidence in this area is not conclusive.

• Pneumonia: Based on one prospective randomized study, regular application of povidone-iodine in the mouth and throat may decrease the prevalence of ventilator-associated pneumonia in patients with severe head trauma. Evidence in this area is not conclusive.

• Post-Caesarean endometritis: Preoperative vaginal scrub with povidone-iodine decreases the incidence of endometritis (inflammation of the uterine lining, the endometrium) after a Caesarean section. This intervention does not seem to decrease the overall risk of postoperative fever or wound infection.

• Renal pelvic instillation sclerotherapy (RPIS): Povidone-iodine 0.2% has been shown to be as effective for RPIS as 1% silver nitrate.

• Septicemia (serious bacterial infections in the blood): Rinsing with povidone-iodine may help reduce the incidence and severity of bacterial infections of the blood.

• Wound healing: It is not clear if healing of wounds or skin ulcers is improved with the application of iodine solutions to the affected area. Iodine solutions may assist with sterilization as a part of a larger approach to the healing process.

• Supplements should be taken under the supervision of a healthcare provider. There have been reports of severe and even fatal reactions to iodine. Avoid iodine-based products if allergic to iodine. Do not use for more than 14 days. Lugol solution and saturated solution of potassium iodide (SSKI, PIMA) should be avoided in patients with pulmonary edema, bronchitis, known tuberculosis, or hyperkalemia (above normal potassium blood levels), because of potential side effects from excess iodine or potassium. Use cautiously when applying to the skin, because iodine may irritate or burn tissues. Use sodium iodide cautiously in those with kidney failure or gastrointestinal obstruction (blockage in the stomach and intestine). Iodine is safe in recommended doses for pregnant or breastfeeding women. Avoid povidone-iodine (a widely used antiseptic preparation of polyvinylpyrrolidone and iodine) for perianal (around the anus) preparation during delivery. Avoid povidone-iodine for preventing infection after delivery.

• Iron: Iron is an essential mineral.

• Attention-deficit hyperactivity disorder (ADHD): Based on preliminary data, taking iron by mouth may improve symptoms of attention-deficit hyperactivity disorder (ADHD). More study is necessary before a conclusion can be drawn.

• Fatigue in women with low ferritin levels: Ferrous sulfate may improve fatigue primarily in women with borderline or low serum ferritin concentrations. Further research is needed to confirm these results.

• Improving cognitive performance related to iron deficiency: Taking iron by mouth seems to improve cognitive function related to iron deficiency in iron-deficient children and adolescents. Further research is needed to confirm the potential benefit of iron in this indication. Iron supplements are not recommended for improving cognitive performance in non-iron-deficient people.

• Lead toxicity: Iron deficiency may increase the risk of lead poisoning in children. However, the use of iron supplementation in lead poisoning should be reserved for those individuals who are truly iron deficient or for those individuals with continuing lead exposure, such as continued residence in lead-exposed housing.

• Preventing anemia associated with preterm/low-birthweight infants: Further study of prenatal iron supplementation is needed before a firm conclusion can be made regarding the effects of anemia on preterm/low-birthweight infants.

• Preventing iron deficiency in exercising women: Preliminary studies suggest that iron supplementation may reverse mild anemia after exercise, improve energy, and enhance performance. However, other research results are conflicting. Further research is needed in this area before firm conclusions can be made.

• Prevention of iron deficiency after blood donation: The results of early study indicate that elemental iron may adequately compensate for iron loss in males and females who donate whole blood up to four (for females) or six (for males) times per year.

• Prevention of iron deficiency anemia due to gastrointestinal bleeding: Intravenous high-dose iron sucrose therapy in patients with iron deficiency anemia due to gastrointestinal blood loss appears to be safe, and therefore is a therapeutic option that may save time and improve patient compliance. More study is needed in this area.

• Treatment of predialysis anemia: Adequate iron supplementation may be beneficial as an adjunct therapy with erythropoietin in the treatment of predialysis anemia. Predialysis anemia should be treated by a qualified healthcare provider. More study is needed in this area.

• Allergic reactions to iron are unlikely. Avoid if allergic to products containing iron. Avoid excessive intake. Avoid iron supplements with blood disorders that require frequent blood transfusions. Use iron supplement cautiously with a history of kidney disease, intestinal disease, heart disease, peptic ulcer disease, enteritis (inflammation of the small intestine), colitis (inflammation of the colon, or large intestine), pancreatitis (inflammation of the pancreas), hepatitis (inflammation of the liver), or alcoholism. Use cautiously if older than 55 years old, as use may increase the risk of heart disease. Pregnant or breastfeeding women should consult their healthcare professionals before beginning iron supplementation.

• Magnesium: Magnesium is a mineral nutrient. Good sources of dietary magnesium are green vegetables (such as spinach), whole grains, nuts, legumes, and halibut.

• Acute myocardial infarction (heart attack): Magnesium injected into the veins has been reported to reduce irregular heartbeat (arrhythmia), which commonly occurs during a heart attack. It is unclear whether magnesium therapy injected into the vein reduces number of deaths caused by heart attacks. Magnesium is an alternative therapy for patients who are not able to take traditional therapies for the treatment of a heart attack.

• Cardiac arrest (loss of heart function): Cardiac arrest is a life-threatening event in which the heart stops contracting properly. Because of an apparent benefit of magnesium for heart attack, magnesium has been used together with other agents for CPR (cardiopulmonary resuscitation). However, it is unclear whether magnesium is the ideal treatment choice for CPR, due to conflicting scientific studies. Additional high-quality clinical study is needed in this area.

• Chronic obstructive pulmonary disease (COPD): Chronic obstructive pulmonary disease (COPD) is a progressive lung disease in which the airways become narrowed. The greatest risk factor for COPD is smoking. Acute attacks of COPD are commonly seen and difficult to treat. The administration of magnesium sulfate into the vein after beta-agonist drugs (drugs that help with breathing) was found to be safe and modestly effective in the treatment of acute flare-ups of COPD. This combination was more effective than beta-agonist therapy alone. More high-quality clinical study is necessary to draw a conclusion.

• Coronary artery disease (heart disease): Experimental evidence has suggested that magnesium may play a beneficial role in regulating blood clot formation. Clinical study suggested that taking magnesium by mouth may inhibit the formation of blood clots in stable patients with heart disease (coronary artery disease). Additional research is needed in this area.

• Fibromyalgia: Fibromyalgia is a disorder that causes chronic widespread pain and a painful response to gentle touch. Other features include marked fatigue, sleep disturbance, and joint stiffness. Limited research found that Super Malic® (containing malic acid and magnesium) may be beneficial for this condition. Additional research is needed to confirm these results.

• High blood pressure: It is unclear whether oral magnesium supplementation is able to lower blood pressure in patients with mild-to-moderate high blood pressure or prevent the onset of high blood pressure. Higher dosages of magnesium are associated with a decrease in blood pressure to very low blood pressure levels. Several studies have reported a small but insignificant decrease in blood pressure with magnesium. Further research is needed for the use of magnesium in the treatment of high blood pressure.

• Leg cramps (during pregnancy): Leg cramps are a common problem during pregnancy, and pregnant women often have low blood levels of magnesium. Therefore, it has been suggested that raising magnesium levels may decrease leg cramps during pregnancy. Magnesium taken by mouth has been reported to reduce pregnancy-related leg cramps. Additional research is needed in this area.

• Migraine headache: Migraine headaches may be extremely painful and are often accompanied by nausea. More women experience migraine headaches than men. Furthermore, migraine headaches in women may be related to the menstrual cycle. Magnesium has been evaluated for use in migraines. Human studies have found that magnesium sulfate may reduce the intensity of migraine headaches. Low magnesium levels may increase menstrual-related migraines in susceptible women. Additional research is needed to confirm these results.

• Mitral valve prolapse (heart valve disease): Mitral valve prolapse (MVP) syndrome is a common disorder characterized by a variety of complaints that impact the quality of life. Low magnesium levels and an excess of the catecholamine and adrenaline have been suggested as contributing factors in causing MVP. Many patients with heavily symptomatic mitral valve prolapse have low magnesium levels in the blood. Magnesium supplementation has been reported to improve most mitral valve prolapse. Additional study is needed to reach a conclusion.

• Muscle spasms: Magnesium may help prevent involuntary muscle twitching caused by the drug succinylcholine (a neuromuscular blocker). Involuntary muscle twitching is an adverse effect of patients undergoing general anesthesia. Additional high-quality study is needed to confirm these results.

• Heart attack prevention (myocardial infarction prevention): Magnesium has been used in the treatment of a heart attack. Therefore, magnesium therapy by mouth as been considered as preventive therapy in patients surviving acute heart attacks. Available human study did not show benefit of oral magnesium therapy for prevention in these individuals. The research also suggested that the risk of heart problems might have been increased. Additional research is needed in this area.

• Pregnancy nutritional supplement:Many women have low magnesium levels in the body. Magnesium supplementation has been given during pregnancy in order to reduce pregnancy complications. Currently, there is not enough evidence to support magnesium supplementation during pregnancy as a means to improve the health of the mother or fetus. Additional research is needed in this area.

• Premenstrual syndrome (PMS):Premenstrual syndrome includes many physical, psychological, and emotional symptoms related to the menstrual cycle. Symptoms usually appear two weeks before the onset of menstrual cycle and in some cases significantly impact a woman's daily routine during that period. Oral magnesium has been reported to benefit mood changes associated with premenstrual syndrome (PMS). Additional research is needed in this area.

• Avoid in patients with known allergy to magnesium or other products found in magnesium supplements. Magnesium allergy is reported to be extremely rare. Magnesium may cause stomach irritation, nausea, vomiting, diarrhea, decreased skeletal muscle tone, and decreased estrogen levels. High blood levels of magnesium (hypermagnesemia) may cause thirst; drowsiness; low blood pressure; delirium; coma; heart, muscle, and respiratory disorders; and death. Toxic levels of magnesium may cause depression of the central nervous system. Magnesium may increase the risk of bleeding, and caution is advised in patients with bleeding disorders or those who are taking drugs, such as warfarin (Coumadin®), that may increase the risk of bleeding. Dosing adjustments may be necessary. Avoid in patients with kidney disorders and atrioventricular heart block (when the electric signal from the heart's upper to lower chambers is not being sent correctly). Avoid using magnesium as a laxative in patients with stomach disorders. Patients taking antidiabetic agents, blood pressure-lowering agents, or antibiotics (such as fluoroquinolones and cephalosporins) should use magnesium cautiously. Side effects appear to be uncommon with therapeutic doses of magnesium in infants or women who are pregnant or breastfeeding. According to the National Institute of Health's Lactation and Toxicology Database (LactMed), magnesium sulfate and magnesium hydroxide are acceptable to use during breastfeeding.

• Niacin: Niacin (Vitamin B3) is a B-complex vitamin found in many foods such as liver, poultry, fish, nuts, and dried beans.

• Age-related macular degeneration (AMD): Niacin may benefit the choroidal blood vessels, which underlie the region of the retina called the macula. Age-related macular degeneration (AMD) may result from disrupted blood flow in the choroidal vessels. Studies suggest that niacin may be used to treat AMD, but more well-designed studies are needed.

• Alzheimer's disease/cognitive decline: Dementia may be caused by severe niacin insufficiency, but it is unclear whether variation in intake of niacin in the usual diet is linked to neurodegenerative decline or Alzheimer's disease. Further research is needed before a conclusion can be drawn.

• Diabetes (type 1/type 2): Niacinamide may prevent diabetes or delay the need for insulin. More research is needed to determine if niacinamide delays or prevents the onset of insulin dependence in individuals with type 1 diabetes. Niacin has been used to treat dyslipidemia (abnormal amounts of cholesterol or fats in the blood) associated with type 2 diabetes. However, this treatment has been controversial, because it may worsen blood sugar control. Patients should seek medical advice before starting niacin.

• Headaches: There is not enough information about the treatment or prevention of headaches with niacin. More research is needed.

• High blood phosphorus level (hyperphosphatemia): Niacinamide may reduce the high serum phosphate levels in hyperphosphatemia. However, more research is needed before niacinamide can be used to treat hyperphosphatemia.

• Osteoarthritis (niacinamide): Preliminary human studies suggest that niacinamide may be useful in the treatment of osteoarthritis. Further research is needed before a conclusion can be made.

• Skin conditions: Niacinamide has been used in skin care products, including moisturizers, antiaging products, and rosacea treatments. The benefits of niacinamide in skin care needs to be further studied before conclusions can be made.

• Avoid niacin (vitamin B3) if allergic to niacin or niacinamide. Avoid with a history of liver disease, irregular heartbeat, heart disease, blood clotting, bleeding disorders, asthma, anxiety, panic attacks, thyroid disorders, stomach ulcers, gout, or diabetes. Avoid if pregnant or breastfeeding.

• Pantothenic acid (vitamin B5): Pantothenic acid (vitamin B5) is found in many foods, including, meats, liver, kidney, fish, shellfish, chicken, vegetables, legumes, yeast, eggs, and milk.

• Athletic performance: There is currently insufficient scientific evidence in this area in order to form a clear conclusion.

• Attention-deficit hyperactivity disorder (ADHD): There is currently insufficient scientific evidence in this area in order to form a clear conclusion.

• Burns: Vitamin supplementation is often recommended in individuals who have sustained severe burns, due to loss of nutrients and increased metabolic needs. It is unclear if vitamin B5 has specific beneficial effects in burn healing beyond its usual functions in the body.

• High cholesterol: Pantothenic acid itself has not been shown to have any cholesterol-lowering effects. However, a chemical derivative of pantothenic acid called pantethine has been studied for this purpose, with compelling preliminary evidence in humans.

• Osteoarthritis: There is currently insufficient scientific evidence in this area in order to form a clear conclusion.

• Rheumatoid arthritis: It has been reported that pantothenic acid levels are lower in the blood of patients with rheumatoid arthritis compared to healthy individuals. However, it is not clear if this is a cause, effect, or a beneficial adaptive reaction. There is currently insufficient scientific evidence in this area in order to form a clear conclusion.

• Wound healing: In animal research, pantothenic acid taken by mouth or applied directly to the skin has been associated with accelerated skin wound healing. However, early human study results conflict. Additional evidence is necessary before a clear conclusion can be reached regarding this use of pantothenic acid or dexpanthenol.

• Avoid if allergic to pantothenic acid or dexpanthenol, which is converted to pantothenic acid in the body. Avoid with gastrointestinal blockage. Pantothenic acid is generally considered safe in pregnant and breastfeeding women when taken at recommended doses.

• Riboflavin: Riboflavin (vitamin B2) is a vitamin that is needed for normal cell function, growth, and energy production.

• Anemia: Some research suggests that riboflavin may play an adjunct role in the treatment of iron deficiency anemia and sickle cell anemia. Levels of riboflavin may be low in these conditions. Correction of riboflavin deficiency in individuals who are both riboflavin deficient and iron deficient appears to improve response to iron therapy.

• Anorexia/bulimia: Levels of important nutrients are often low in individuals with the eating disorders anorexia or bulimia, with up to 33% of patients deficient in vitamins B2 (riboflavin) and B6 (pyridoxine). Dietary changes alone, without additional supplements, may often bring vitamin B levels back to normal. However, extra B2 and B6 may be required. Nutritional and medical guidance for such patients should be under the direction of a qualified healthcare professional.

• Cataracts: It has been suggested that low riboflavin levels may be a risk factor for developing cataracts (clouding of the lens of the eye that affects vision) or that riboflavin supplementation may be beneficial for prevention. Additional evidence is needed before a clear conclusion can be drawn.

• Cognitive function: Adequate nutrient supplementation with riboflavin may be required for the maintenance of adequate cognitive function. However, more research is needed.

• Depression: Treatment with B-vitamins, including riboflavin, has been reported to improve depression scores in patients taking tricyclic antidepressants. This may be related to tricyclic-caused depletion of riboflavin levels.

• Esophageal cancer (prevention and treatment): Riboflavin supplementation has been studied in the prevention and treatment of esophageal cancer, mostly in China, with mixed results. A clear conclusion cannot be drawn at this time.

• Ethylmalonic encephalopathy: Although the exact pathogenesis of this inherited disorder that affects several body systems is unknown, some research suggests that riboflavin may lead to slight improvements in motor function, cognitive behavior, and diarrhea.

• Malaria: It remains unclear how riboflavin supplementation may affect malarial infections.

• Migraine headache prevention: Several studies suggest that high-dose riboflavin may help prevent migraine headaches. However, more well-designed studies are needed before conclusions can be made.

• Pre-eclampsia: Limited study has reported an association between low riboflavin levels and an increased risk of pre-eclampsia (high blood pressure in pregnancy). However, it is not clear if low riboflavin levels are a cause or consequence of this condition, or if additional supplementation is warranted in pregnant women at risk of pre-eclampsia or eclampsia (beyond the routine use of prenatal vitamins).

• Avoid if allergic to riboflavin. Because the amount of riboflavin a human can absorb is limited, riboflavin is generally considered safe. Riboflavin is generally regarded as being safe during pregnancy and breastfeeding when taken at the recommended dietary allowance (RDA) of 1.4 milligrams daily.

• Selenium:Selenium is a trace mineral found in soil, water, and some foods. It is an essential element in several metabolic pathways.

• Asthma: Preliminary research reports that selenium supplementation may help improve asthma symptoms. Further research is needed to confirm these results.

• Blood disorders: Selenium supplementation may offer benefits in patients with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and chronic hemolysis. Selenium supplementation may also affect platelet function and blood clotting.

• Bronchitis: Because selenium is proposed to have a role in immune function, selenium supplementation has been studied in patients with various infections. Some evidence suggests that selenium may promote recovery from bronchitis and pneumonia caused by respiratory syncytial virus (RSV). Though selenium may correct selenium deficiency in patients with bronchitis, more studies are needed to show its effectiveness in treating respiratory infections.

• Cancer prevention: Several studies suggest that low levels of selenium may be a risk factor for developing cancer, particularly gastrointestinal, gynecological, lung, colorectal, and esophageal cancer. Studies have shown significantly reduced risk of some (but not all) cancers in subjects taking selenium supplements. Selenium supplementation may reduce cancer incidence in men more than women. Ongoing trials are examining the precise role of selenium in reducing cancer risk.

• Cancer treatment: Several studies suggest that low levels of selenium (measured in the blood or in tissues such as toenail clippings) may be a risk factor for developing cancer, particularly prostate, gastrointestinal, gynecological, and colorectal cancer. Population studies suggest that people with cancer are more likely to have low selenium levels than healthy matched individuals, but in most cases it is not clear if the low selenium levels are a cause or merely a consequence of disease. It remains unclear if selenium is beneficial in the treatment of any type of cancer.

• Cardiomyopathy: Low selenium levels have been associated with the development of cardiomyopathy, a weakening of the heart muscle, and selenium supplementation is likely of benefit in such cases (for example in Keshan disease and Chagas disease). However, most cases of cardiomyopathy are not due to low selenium levels, and therefore selenium may not be helpful. It has been suggested that low selenium levels may be a risk for coronary heart disease, although this remains unclear.

• Cardiovascular disease(prevention): Studies on the effects of selenium intake and supplementation on cardiovascular disease have yielded inconsistent findings. Better-designed trials are needed to reach a firm conclusion.

• Central nervous system disorders: Studies have consistently shown that antioxidants have no clinical benefits in motor neuron diseases such as amyotrophic lateral sclerosis (ALS). Although the research thus far does not discourage selenium supplementation in patients, more research is needed to determine if selenium may be a beneficial treatment for central nervous system disorders.

• Chemotherapy side effects: Study results of selenium supplementation during chemotherapy are mixed. General concern has been raised that antioxidants may interfere with radiation therapy or some chemotherapy agents, which themselves may depend on oxidative damage to tumor cells for anticancer activity. Therefore, patients undergoing cancer treatment should speak with their oncologist and pharmacist before taking selenium supplements.

• Critical illness: Selenium is known to play important roles in human health. Though some studies have produced promising results, many showed no evidence that selenium may improve health or decrease mortality in critically ill patients. Research is ongoing.

• Cystic fibrosis: Preliminary research of selenium supplementation in cystic fibrosis patients has yielded indeterminate results. Further research is needed in this area before a conclusion can be drawn.

• Dandruff: Studies have reported that selenium-containing shampoos may help improve dandruff, and selenium is included in some commercially available products.

• Dialysis: The benefits of selenium supplementation in dialysis patients remain unclear. Some methods of dialysis may lower plasma selenium levels.

• Eye disorders: Although selenium appears to be involved in cataract development and uveitis (eye inflammation), it is not known whether selenium supplements may affect the risk of developing these disorders. Research in this area is warranted.

• Fatigue: Evidence of benefit is inconclusive in this area.

• High blood pressure: Some studies have reported that low serum selenium levels may be related to increased blood pressure. More research is needed in this area.

• HIV/AIDS: Selenium supplementation has been studied in HIV/AIDS patients, and some reports associate low selenium levels with complications such as cardiomyopathy. It remains unclear if selenium supplementation is beneficial in patients with HIV, particularly during antiretroviral therapy.

• Infection prevention: Preliminary research reports that selenium may be beneficial in the prevention of several types of infection, including recurrence of erysipelas (bacterial skin infection associated with lymphedema), sepsis, or Mycoplasma pneumonia. Selenium may help prevent infection by stimulating immune function. Further research is needed to confirm these results before a clear conclusion can be made.

• Infertility: Selenium supplementation has been studied for male infertility and sperm movement, with mixed results. Evidence is lacking regarding the potential effects on female infertility.

• Intracranial pressure symptoms: Preliminary research shows a decrease of symptoms of elevated intracranial pressure (headaches, nausea, vomiting, vertigo, unsteady gait, speech disorders, and seizures). More research is needed before a conclusion can be made.

• Liver disease: Selenium supplementation has been studied in various liver disorders, including hepatitis, cirrhosis, and liver cancer, with mixed results.

• Longevity/antiaging: Because antioxidant supplements are thought to slow aging and prevent disease, selenium supplementation may increase longevity. However, results from clinical trials are mixed, and it is still unclear whether selenium supplementation may affect mortality in healthy individuals.

• Low birthweight: Selenium supplementation has been studied in low-birthweight infants. Additional evidence is warranted in this area before a clear conclusion can be drawn.

• Malabsorption: Low selenium status has been demonstrated in several syndromes where nutrients are not taken up normally in the digestive tract. Low selenium status has also been observed in some digestive and gastrointestinal allergic conditions. There is some evidence that children with food allergies have a higher risk of selenium deficiency. There is no clear benefit of selenium supplementation as a therapy for malabsorptive syndromes, although vitamin supplementation in general may be warranted.

• Pancreatitis: There is inconclusive evidence regarding the use of selenium in pancreatitis.

• Physical endurance: The antioxidant effects of selenium have been suggested to improve physical endurance. However, the available evidence suggests that selenium supplementation does not affect physical performance or endurance training.

• Postoperative recovery: There is some evidence that selenium may aid postoperative recovery and reduce edema (swelling) after surgery. Patients with severe inflammation, resulting from surgeries or extensive burns, may benefit from supportive selenium therapy. More studies are needed to determine whether selenium is a suitable addition to postoperative therapy and care.

• Pre-eclampsia: Preliminary study in women with pregnancy-induced high blood pressure has reported reduced edema (swelling), without significant impact on birth outcomes. No clear conclusion can be drawn in the absence of additional well-designed research.

• Quality of life: Studies of selenium supplementation for mood elevation and quality of life have yielded mixed results. Further research is needed before a firm conclusion may be reached.

• Radiation side effects: Selenium supplementation has been used in combination therapy to treat radiation side effects. Additional research is necessary before a clear conclusion can be drawn.

• Rheumatoid arthritis: Selenium supplementation has been studied in rheumatoid arthritis patients with mixed results. Additional research is necessary before a clear conclusion can be drawn.

• Seizures: It is unclear whether serum selenium levels are related to seizures in patients with epilepsy or brain tumors. More research needs to examine whether selenium supplementation may affect the frequency or severity of seizures.

• Sepsis (severe bacterial infection in the blood): Study results of selenium supplementation in septic patients are mixed.

• Skin disorders: Taking selenium by mouth has been studied for its effects on psoriasis and lesions induced by arsenic or the human papilloma virus (HPV). Selenium has also been used to treat eczema and to increase the rate of burn wound healing. Although some results appear promising, the overall results are mixed. Additional study is needed in this area.

• Sunburn prevention: Protection from light was initially observed in preliminary research using selenium supplementation and other antioxidants, although there is some evidence of ineffectiveness in preventing light-induced erythema (skin redness).

• Thyroid conditions: Thyroid function is thought to depend on selenium, and thyroid problems are common in patients with selenium deficiency. Selenium has been suggested to improve goiter, as well as inflammatory activity in chronic autoimmune thyroiditis or Graves' disease. Further research is needed.

• Trauma: Because selenium levels and thyroid hormones are disrupted in trauma patients, selenium supplementation has been suggested as a treatment for critically injured patients. Currently, there is not enough evidence to recommend the use of selenium therapy in severe injuries.

• Yeast infection: Commercially available 1% selenium sulfide shampoo has been reported as equivalent to sporicidal therapy in the adjunctive treatment of tinea capitis and tinea versicolor infections, although further high-quality evidence is warranted.

• Hypersensitivity to selenium is unlikely. Avoid individuals with a known allergy or hypersensitivity to products containing selenium. Selenium deficiency may occur in areas where the soil content of selenium is low. Deficiency may affect thyroid function and cause conditions such as Keshan disease. Selenium deficiency is also commonly seen in patients on total parenteral nutrition (TPN) as their sole source of nutrition. Gastrointestinal disorders may decrease the absorption of selenium, resulting in depletion or deficiency.

• Thiamin (thiamine), vitamin B1: Thiamin (thiamine), also called vitamin B1, is a water-soluble vitamin.

• Alzheimer's disease: Because thiamin deficiency may result in a form of dementia (Wernicke-Korsakoff syndrome), its relationship to Alzheimer's disease and other forms of dementia has been investigated. Whether thiamin supplementation is of benefit in Alzheimer's disease remains controversial. Further evidence is necessary before a firm conclusion can be reached.

• Atherosclerosis (prevention in patients with acute hyperglycemia, impaired glucose tolerance (IGT), and diabetes mellitus): Patients with diabetes are at risk of developing atherosclerosis. This happens when cholesterol and other substances build up and clog the arteries. Thiamin has been studied as a way to help widen arteries that are too narrow. Regular intake of thiamin may help slow the progression of atherosclerosis. However, additional research is needed.

• Athletic performance: There is inconclusive scientific evidence in this area.

• Cancer: Thiamin deficiency has been observed in some cancer patients, possibly due to increased metabolic needs. It is not clear if lowered levels of thiamin in such patients may actually be beneficial. Currently, it remains unclear if thiamin supplementation plays a role in the management of any particular type of cancer.

• Cataract prevention: Preliminary evidence suggests that high dietary thiamin intake may be associated with a decreased risk of cataracts. Further evidence is necessary before a firm conclusion can be reached.

• Coma/hypothermia of unknown origin: The administration of thiamin is often recommended in patients with coma or hypothermia (low body temperature) of unknown origin, due to the possible diagnosis of Wernicke's encephalopathy.

• Crohn's disease: Decreased serum thiamin levels have been reported in patients with Crohn's disease. It is not clear if routine thiamin supplementation is beneficial in such patients generally.

• DIDMOAD (Wolfram) syndrome: DIDMOAD (Wolfram) syndrome is a rare inherited disease that results in diabetes mellitus, optic atrophy (a condition affecting the optic nerve), diabetes insipidus (a condition in which the kidneys are unable conserve water), sensorineural deafness (hearing loss that is due to damage to the inner ear, the auditory nerve, or the brain), and occasionally megaloblastic anemia. The defect is believed to cause a decrease in the enzyme that converts thiamin to its active form. Management, including thiamin supplementation, should be under strict medical supervision.

• Heart failure (cardiomyopathy): Chronic severe thiamin deficiency may cause heart failure (wet beriberi), a condition that merits thiamin supplementation. It is not clear that thiamin supplementation is beneficial in patients with heart failure due to other causes. However, it is reasonable for patients with heart failure to take a daily multivitamin containing thiamin because some of these individuals may be thiamin deficient. Diuretics may lower thiamin levels. Since diuretics are commonly administered to patients with heart failure, patients taking diuretics are at an increased risk of thiamin deficiency. This area remains controversial, and further evidence is necessary before a firm conclusion can be reached.

• Leg cramps (during pregnancy): Vitamin B supplements have been used to treat leg cramps during pregnancy. However, additional studies are needed to determine if it is effective.

• Pyruvate dehydrogenase deficiency: There is preliminary evidence of clinical improvements in children with this neurodegenerative disorder following thiamin administration. Further evidence is necessary before a firm conclusion can be reached.

• Subclinical thiamin deficiency in the elderly: While typically asymptomatic, the elderly have been found to have lower thiamin concentrations than younger people. There is limited evidence that thiamin supplementation may be beneficial in individuals with persistently low thiamin blood levels. Further study is necessary before a firm conclusion can be formed in this area.

• Thiamin is generally considered safe and relatively nontoxic, even at high doses. Avoid if allergic or hypersensitive to thiamin. Thiamin appears safe if pregnant or breastfeeding when taken at the recommended dietary allowance of 1.4 milligrams daily.

• Vitamin A: Vitamin A is a fat-soluble vitamin that is needed for vision.

• Antioxidant: The benefits for humans of the potential antioxidant activity of vitamin A are unclear.

• Breast cancer: Research results are unclear as to whether vitamin A is beneficial in the treatment or prevention of breast cancer. Patients receiving chemotherapy or radiation therapy for cancer should speak with their doctors before taking antioxidants, such as vitamin A, during treatment, due to possible interfering effects of vitamin A.

• Cataract prevention: Vitamin A has been suggested to prevent cataract formation. Carotenoids such as beta-carotene, lutein, and zeaxanthin may decrease the risk of severe cataracts. There is insufficient evidence to form a clear conclusion at this time.

• Diarrhea: Vitamin A may reduce the severity and duration of diarrheal episodes in malnourished children, but not in well-nourished children. Because diarrhea is a major cause of sickness and death in developing countries, vitamin A supplementation may be beneficial in undernourished children with diarrhea.

• HIV Infection: The role of vitamin A in the prevention, spread, or treatment of HIV is controversial and not well established. Based on the available scientific research, clear conclusions are lacking.

• Immune function: Vitamin A deficiency may compromise immunity. Clear evidence is lacking on whether or not additional vitamin A supplementation is beneficial for immune function in patients who are not vitamin A deficient.

• Infant mortality (death): The limited research in this area has produced conflicting results. Some evidence suggests possible decreases in infant death with vitamin A supplementation, while other research reports no benefits. Based on the available scientific research, conclusions are unclear.

• Iron deficiency anemia: Vitamin A supplementation in combination with iron may have beneficial effects in patients with iron deficiency anemia, including children and pregnant women. It is unclear if benefits exist for individuals who are not vitamin A deficient. This area remains controversial, and further evidence is necessary before a clear conclusion may be drawn.

• Pancreatic cancer: Vitamin A supplementation has not been shown to improve response to gemcitabine, a drug used to treat pancreatic cancer. It is unclear whether vitamin A provides any benefits to patients with pancreatic cancer. More research is needed in this area.

• Parasite infection (Ascaris reinfection): After deworming, children receiving vitamin A supplements may be at lower risk of Ascaris parasite reinfection. Children with stunted growth may benefit less from vitamin A supplementation.

• Photorefractive keratectomy: Photorefractive keratectomy is a type of laser eye surgery used to correct nearsightedness. High-dose vitamin A supplementation in addition to vitamin E supplementation has been suggested to improve ocular healing after surgery and to improve visual acuity. Additional evidence is necessary before a definitive conclusion may be reached.

• Pneumonia (children): Early research suggests that a moderate dose of vitamin A supplementation may not affect the duration of uncomplicated pneumonia in underweight or normal-weight children five years old or younger. However, a beneficial effect was seen in children with high baseline serum retinol concentrations.

• Pregnancy-related complications: Maternal vitamin A deficiency is common in developing countries. Beta-carotene, a carotenoid converted to vitamin A by the human body, may reduce pregnancy-related complications and death in such individuals. However, excess intake of vitamin A has been reported to increase the risks of some birth defects. Vitamin A supplementation above the recommended dietary allowance (RDA) is therefore not recommended in pregnancy.

• Skin aging (improving aging skin appearance): Some studies suggest that topical vitamin A may improve the appearance and integrity of aged skin.

• Skin cancer prevention: It is unclear if vitamin A or beta-carotene, taken by mouth or used on the skin with sunscreen, is beneficial in the prevention or treatment of skin cancers or wrinkles.

• Stomach cancer (prevention): Vitamin supplementation has been proposed to reduce the rate of stomach cancer. However, there is some evidence suggesting that vitamin A does not reduce the rates of stomach cancer or precancerous stomach lesions. More research is needed to examine whether vitamin A has any effects on stomach cancer.

• Tumors (polyp prevention): Alpha-carotene and vitamin A may protect against recurrence of polyps and adenoma in nonsmokers and nondrinkers. Further research is needed before a clear conclusion may be drawn.

• Viral infection (norovirus (NoV) infection): Further research is needed in this area.

• Weight loss: Daily vitamin A with calcium has been suggested for weight loss. In early research, young women lost an average of two pounds after two years of supplementation. Further study is needed before conclusions can be drawn.

• Wound healing: In preliminary study, retinol palmitate, a form of vitamin A, significantly reduced rectal symptoms of radiation proctopathy. Radiation proctopathy is a complication that sometimes occurs after treatment of pelvic malignancies with radiation therapy. The effect of retinol palmitate may be due to wound-healing effects. Further research is needed to confirm these results.

• Avoid if allergic to vitamin A. intake levels. Use cautiously in those with liver disease or alcoholism. Smokers who consume alcohol and beta-carotene may have an increased risk of developing lung cancer or heart disease. Vitamin A appears safe in pregnant women if taken in recommended doses. Use cautiously if breastfeeding, because the benefits or dangers to nursing infants are not clearly established.

• Vitamin B6: Vitamin B6 (also called pyridoxine) is commonly found in cereal grains, legumes, vegetables (e.g., carrots, spinach, peas, or potatoes), milk, cheese, eggs, fish, liver, meat, and flour.

• Akathisia (movement disorder): Some prescription drugs called neuroleptics, which are used in certain psychiatric conditions, may cause movement disorders as an unwanted side effect. Vitamin B6 has been studied for the treatment of acute neuroleptic-induced akathisia (NIA) in schizophrenic and schizoaffective disorder patients. Preliminary results indicate that high doses of vitamin B6 may be useful additions to the available treatments for NIA, perhaps due to its combined effects on various systems of neurotransmitters, chemicals that carry signal from nerve cells to other cells. Further research is needed to confirm these results.

• Angioplasty: There are conflicting findings about the potential benefit or harm of taking folic acid plus vitamin B6 and vitamin B12 following angioplasty, the mechanical widening of a narrowed or obstructed blood vessel. Further research is needed before a conclusion can be made.

• Asthma: Preliminary research suggests that children with severe asthma might have inadequate pyridoxine status. Theophylline, a prescription drug used to help manage asthma, seems to lower pyridoxine levels. Studies of pyridoxine supplementation in asthma patients taking theophylline have yielded conflicting results. Further research is needed before a conclusion can be drawn.

• Attention-deficit hyperactivity disorder (ADHD): Some research suggests that pyridoxine supplementation alone or in combination with high doses of other B vitamins might help ADHD. Other studies show no benefit. Further research is needed before a conclusion can be drawn.

• Birth outcomes: Studies of birth outcomes with vitamin B6 supplementation during pregnancy have yielded mixed results. Further well-designed clinical trials are needed.

• Cancer prevention: Data suggest that vitamin B6 may help lower the risk of colon cancer. However, supplementation with a combination of folic acid, vitamin B6, and vitamin B12 did not decrease the risk of breast cancer. There is evidence that male smokers with higher serum levels of pyridoxine may have a lower risk of lung cancer. Well-designed clinical trials of pyridoxine supplementation are needed.

• Cardiovascular disease/hyperhomocysteinemia: High homocysteine levels in the blood (hyperhomocysteinemia) are a risk factor for cardiovascular disease, blood clotting abnormalities, atherosclerosis, myocardial infarction (heart attack), and ischemic stroke. Taking pyridoxine supplements alone or in combination with folic acid has been shown to be effective for lowering homocysteine levels. However, it is not clear if lowering homocysteine levels results in reduced cardiovascular morbidity and mortality. Decreased pyridoxine concentrations are also associated with increased plasma levels of C-reactive protein (CRP), an indicator of inflammation that has been linked to increased illness due to heart disease. In a large, long-term study, a combination pill containing folic acid, vitamin B6, and vitamin B12 did not reduce the risk of cardiovascular disease in high-risk women. Investigation of more patients undergoing treatment with vitamin B6 is needed as study results conflict.

• Carpal tunnel syndrome: Preliminary data suggest that large doses of vitamin B6 may be helpful for carpal tunnel syndrome. Well-designed clinical trials are needed before firm conclusions can be drawn.

• Depression: Preliminary evidence suggests that because pyridoxine increases levels of the neurotransmitters serotonin and GABA in the blood, it may benefit people in with depression. Well-designed clinical trials are needed to confirm potential benefit.

• Hyperkinetic cerebral dysfunction syndrome: There is preliminary evidence that pyridoxine supplementation might benefit hyperkinetic (hyperactive) children who have low levels of blood serotonin. Further research is needed to confirm these results.

• Immune system function: Vitamin B6 is important for immune system function in older individuals. One study found that the amount of vitamin B6 required to reverse immune system impairments in elderly people was more than the current recommended dietary allowance (RDA). Well-designed clinical trials on vitamin B6 supplementation for this indication are needed before a conclusion can be made.

• Kidney stones (nephrolithiasis): Pyridoxine alone, or taken with magnesium, may decrease urinary oxalate levels, which may contribute to a certain type of kidney stones. Higher pyridoxine intake has been associated with decreased risk of kidney stone formation in women but not in men with no history of stone formation. Benefit has not been proven in other types of kidney stones, such as those associated with high urinary calcium, phosphorus, and creatinine. Further data are needed before a firm conclusion can be drawn.

• Lactation suppression: Studies of pyridoxine used to suppress lactation, or secretion of milk from the mammary glands, have yielded mixed results. Well-designed clinical trials are needed before a firm conclusion can be drawn.

• Pregnancy-induced nausea and vomiting: Studies of the use of pyridoxine alone or in combination with other antinausea treatments in pregnant women have yielded conflicting results. Further research is needed before a strong conclusion can be made.

• Premenstrual syndrome (PMS): There is some evidence that taking pyridoxine orally may improve symptoms of PMS such as breast pain or tenderness and PMS-related depression or anxiety in some patients. Further research is needed before a conclusion can be made.

• Preventing vitamin B6 deficiency associated with taking birth control pills: The need for vitamin B6 supplementation in women taking birth control pills has not been proven, although some studies show decreased pyridoxine levels in these women. Supplementation of B6 should be approached cautiously since the long-term effect of such therapy is uncertain.

• Tardive dyskinesia (involuntary movements): Pyridoxine has some antioxidant effects, which theoretically may benefit patients with tardive dyskinesia. Results from a small high-quality trial suggest a benefit of vitamin B6 on symptoms of tardive dyskinesia. Further research is needed before a conclusion can be made.

• Some individuals are particularly sensitive to vitamin B6 and may experience side effects at lower doses. Avoid excessive dosing. Vitamin B6 is likely safe when taken by mouth in doses that do not exceed the recommended dietary allowance (RDA).

• Vitamin B12: Vitamin B12 is a water-soluble vitamin and is commonly found in many foods like fish, shellfish, meats, and dairy products. Vitamin B12 helps maintain healthy nerve cells and red blood cells.

• Alzheimer's disease: Some patients diagnosed with Alzheimer's disease have been found to have abnormally low vitamin B12 levels in their blood. However, vitamin B12 deficiency itself often causes disorientation and confusion and thus mimics some of the prominent symptoms of Alzheimer's disease. Well-designed clinical trials are needed before a strong conclusion can be made.

• Angioplasty: Some evidence suggests that folic acid plus vitamin B12 and pyridoxine daily may decrease the rate of restenosis, or recurrence of narrowing, in patients treated with balloon angioplasty. But this combination does not seem to be as effective for reducing restenosis in patients after coronary stenting (placement of a supporting tube into a blood vessel). Due to the lack of evidence of benefit and potential for harm, this combination of vitamins should not be recommended for patients receiving coronary stents.

• Breast cancer: Researchers at Johns Hopkins University have reported that women with breast cancer tend to have lower vitamin B12 levels in their blood than women without breast cancer. In a subsequent review of these findings, it was hypothesized that vitamin B12 deficiency may lead to breast cancer, because it could result in less folate being available to ensure proper DNA replication and repair. Higher dietary folate intake is associated with a reduced risk of breast cancer. The risk may be further reduced in women who also consume high amounts of dietary vitamin B12 in combination with dietary pyridoxine (vitamin B6) and methionine. However, there is lack of evidence that dietary vitamin B12 alone reduces the risk of breast cancer.

• Cardiovascular disease/hyperhomocysteinemia: Hyperhomocysteinemia (high homocysteine levels in the blood) is a risk factor for coronary, cerebral, and peripheral atherosclerosis, recurrent thromboembolism, deep vein thrombosis, heart attack, and ischemic stroke. Elevated homocysteine levels may be a marker instead of a cause of vascular disease. However, it is not clear if lowering homocysteine levels results in reduced cardiovascular morbidity and mortality. Folic acid, pyridoxine (vitamin B6), and vitamin B12 supplementation may reduce total homocysteine levels. However, this reduction does not seem to help with secondary prevention of death or cardiovascular events such as stroke or heart attack in people with prior stroke. More evidence is needed to fully explain the association of total homocysteine levels with vascular risk and the potential use of vitamin supplementation.

• Fatigue: There is some evidence that intramuscular injections of vitamin B12 given twice per week might improve the general well-being and quality of life of patients experiencing tiredness or fatigue. However, well-designed clinical trials are needed before a conclusion can be made.

• High cholesterol: Some evidence suggests that vitamin B12 in combination with fish oil might be superior to fish oil alone when used daily to reduce total serum cholesterol and triglycerides. Well-designed clinical trials of vitamin B12 supplementation alone are needed before a conclusion can be drawn.

• Imerslund-Grasbeck disease: Administering vitamin B12 intramuscularly seems to be effective for treating familial selective vitamin B12 malabsorption (Imerslund-Grasbeck disease). Further research is needed to confirm these results.

• Shaky-leg syndrome: Preliminary clinical reports suggest that cyanocobalamin may help relieve tremor associated with shaky-leg syndrome. Further research is needed to confirm these results.

• Sickle cell disease: Early study suggests that a practical daily combination may include folic acid, vitamin B12, and vitamin B6. Further research is needed to confirm these results.

• Avoid vitamin B12 supplements if allergic to cobalamin, cobalt, or any other product ingredients. Avoid with coronary stents or Leber's disease (a hereditary condition marked by acute loss of vision). Use cautiously if undergoing angioplasty (mechanical widening of a narrowed or obstructed blood vessel). Vitamin B12 is generally considered safe when taken in amounts that are not higher than the recommended dietary allowance (RDA).

• Vitamin C (ascorbic acid): Vitamin C (ascorbic acid) is a vitamin that the body needs to form collagen in bones, cartilage, muscle, and blood vessels.

• Asthma: It has been suggested that low levels of vitamin C (or other antioxidants) may increase the risk of developing asthma. The use of vitamin C for the treatment of asthma, particularly exercise-induced asthma, has been studied since the 1980s. However, the evidence in this area remains inconclusive. More research is needed before a clear conclusion can be drawn.

• Bleeding stomach ulcers caused by aspirin: Early evidence suggests that vitamin C may help aspirin-induced stomach damage. More research is needed.

• Cancer prevention: Dietary intake of fruits and vegetables high in vitamin C has been associated with a reduced risk of various types of cancer in population studies (particularly cancers of the mouth, esophagus, stomach, colon, or lung). However, it is not clear that a benefit comes specifically from the vitamin C in these foods, and vitamin C supplements have not been found to be associated with this protective effect. Experts have recommended increasing dietary consumption of fruits and vegetables high in vitamin C, such as asparagus; berries; broccoli; cabbage; melon (cantaloupe; honeydew; watermelon); cauliflower; citrus fruits (lemons; oranges); fortified breads, grains, and cereal; kale; kiwi; potatoes; spinach; and tomatoes.

• Cancer treatment: Vitamin C has a long history of use in cancer therapy in combination with other treatments. More research is needed to determine if this use is effective.

• Complex regional pain syndrome: Clinical study suggests that vitamin C may prevent complex regional pain syndrome among elderly female patients with wrist fractures. Additional studies suggest that vitamin C may help to reduce pain associated with this syndrome.

• Exercise recovery: Vitamin C may prevent endurance exercise-induced lipid damage and muscle damage in healthy people. More research is needed before a conclusion can be made.

• Helicobacter pyloriinfection: Adding vitamin C to triple therapy with omeprazole, amoxicillin, and clarithromycin for Helicobacter pylori gastric ulcer treatment may allow a lower dose of clarithromycin to be used. Further research is needed to confirm these results.

• Ischemic heart disease: Due to its antioxidant properties, vitamin C has been used in patients with ischemic heart disease, which is the result of insufficient blood and oxygen flow to the heart. Early data suggest that vitamin C may have a benefit on blood flow in the heart, but more research is needed to confirm these findings.

• Metabolic abnormalities (alkaptonuria): Alkaptonuria is a disorder characterized by the absence of the enzyme homogentisic acid oxidase, which causes homogentisic acid to collect in the blood and urine. Limited research reports that daily high-dose vitamin C may provide relief of symptoms and slow progression of complications of this disorder. More study is merited in this area.

• Plaque/calculus on teeth: In early studies, reduced amounts of calculus, visible plaque, and bleeding gum sites were observed after the use of vitamin C chewing gum. Further research is needed to confirm these results.

• Pneumonia (prevention): Vitamin C may play a role in the prevention of pneumonia. However, further research is needed to confirm these results.

• Pregnancy: There is not enough evidence to conclude if vitamin C supplementation alone or combined with other supplements is beneficial during pregnancy. Preterm (premature) birth may increase with vitamin C supplementation. Some study results show that daily supplementation may effectively lessen the incidence of premature rupture of chorioamniotic membranes (PROM). A gynecologist and pharmacist should be consulted before taking any herbs or supplements during pregnancy.

• Prostate cancer: Vitamin C has been used in patients with prostate cancer, but the current evidence is mixed.

• Skin damage caused by the sun (UVA-induced): Vitamin C and vitamin E applied to the skin may not prevent UVA-induced skin damage (sunburn). Further research is needed to confirm these findings.

• Skin pigmentation disorders (perifollicular pigmentation): Limited evidence suggests a role for vitamin C in perifollicular pigmentation, which comprises increased color pigment near the hair follicle.

• Stroke prevention: There are variable results of studies that have measured the association of vitamin C intake and risk of stroke. Some studies have reported no benefits, while others have reported that daily low-dose vitamin C may reduce the risk of death from stroke. More research is merited in this area. Individuals at risk of having a stroke should speak with their healthcare providers about the role of vitamin C supplements in stroke prevention.

• Vaginitis: Preliminary human study suggests that vitamin C vaginal tablets given once a day may help patients with nonspecific vaginal inflammation. Further research is needed to confirm these findings.

• Vitamin C is generally considered safe in the amounts commonly found in foods. Vitamin C supplements are also generally considered safe in most individuals if taken in recommended doses. Avoid high doses of vitamin C with glucose-6-phosphate dehydrogenase (G6PD) deficiency, kidney disorders or stones, cirrhosis (scarring and poor function of the liver as a result of chronic liver disease), gout, or paroxysmal nocturnal hemoglobinuria (a bleeding disorder). Vitamin C intake from food is generally considered safe if pregnant or breastfeeding. It is not clear if vitamin C supplements in doses higher than dietary reference intake recommendations are safe for pregnant or breastfeeding women. Vitamin C is naturally found in breast milk.

• Vitamin D: Vitamin D is found in many foods, including fish, eggs, fortified milk, and cod liver oil. Vitamin D is made by human skin exposed to sunlight.

• Anticonvulsant-induced osteomalacia: Supplementation with vitamin D2 has been reported to reduce seizure frequency in initial research. Further study is needed to confirm these results.

• Breast cancer prevention: High-dose vitamin D supplementation may be associated with a slightly reduced risk of developing breast cancer. Additional study in this area is warranted.

• Cancer prevention: Limited research suggests that synthetic vitamin D analogs may play a role in the treatment of human cancers. However, it remains unclear if vitamin D deficiency raises cancer risk, or if an increased intake of vitamin D is protective against some cancers. Until additional trials are conducted, conclusions are lacking on the use of regular vitamin D supplementation to prevent cancer.

• Colorectal cancer: Some data suggest that supplemental vitamin D may prevent the development of colorectal cancer. More research is needed in this area.

• Corticosteroid-induced osteoporosis: Some evidence implies that steroids may impair vitamin D metabolism, further contributing to the loss of bone and development of osteoporosis associated with steroid medications. There is limited evidence that vitamin D may be beneficial to bone strength in patients taking long-term steroids.

• Diabetes (type1/type 2):Type 1 diabetes: It has been reported that infants given calcitriol during the first year of life are less likely to develop type 1 diabetes than infants fed lesser amounts of vitamin D. Other related studies have suggested using cod liver oil as a source of vitamin D to reduce the incidence of type 1 diabetes. There is currently insufficient evidence to form a clear conclusion in this area. Type 2 diabetes: In recent studies, adults given vitamin D supplementation were shown to improve insulin sensitivity. Further research is needed to confirm these results.

• Fall prevention: Multiple trials have found conflicting results for the effects of vitamin D in the prevention of falls. More studies are needed.

• Hepatic osteodystrophy: Metabolic bone disease is common among patients with chronic liver disease, and osteoporosis accounts for the majority of cases. Varying degrees of calcium malabsorption may occur in patients with chronic liver disease due to malnutrition and vitamin D deficiency. Vitamin D that is injected or taken by mouth may play a role in the management of this condition.

• High blood pressure (hypertension): Low levels of vitamin D may play a role in the development of high blood pressure. It has been noted that blood pressure is often elevated under the following conditions: during the winter season, at a further distance from the equator, and in individuals with dark skin pigmentation (all of which are associated with lower production of vitamin D by the skin in response to sunlight). However, the evidence is not clear, and a comparison with more proven methods to reduce blood pressure has not been conducted. Patients with elevated blood pressure should be managed by a qualified healthcare professional.

• Hypertriglyceridemia: There is insufficient evidence in this area.

• Immunomodulation: Preliminary human evidence suggests that vitamin D and its analogs, such as alfacalcidol, may act as immunomodulatory agents. More studies are needed to confirm these results.

• Mortality reduction: Intake of vitamin D may be associated with a reduction in total deaths. Additional evidence is needed to confirm this association.

• Multiple sclerosis (MS): Scientists have detected MS rates to be lower in areas with greater sunlight and higher consumption of vitamin D-rich fish. Preliminary research suggests that long-term vitamin D supplementation decreases the risk of MS; however, additional research is necessary before a firm conclusion can be reached.

• Myelodysplastic syndrome: There is insufficient evidence in this area.

• Osteogenesis imperfecta (OI): OI is a genetic disease that consists of unusually fragile bones that break easily, often under loads that normal bones bear daily, due to a malfunction in the body's production of collagen. Proper calcium and vitamin D intake is essential to maintaining strong bones. Additional research is needed in this area.

• Osteoporosis (cystic fibrosis patients): Osteoporosis is common in patients with cystic fibrosis (due to fat malabsorption, which leads to a deficiency of fat-soluble vitamins such as vitamin D). Taking calcitriol by mouth appears to increase the absorption of calcium and decrease parathyroid concentrations.

• Proximal myopathy: There is insufficient evidence in this area.

• Rickets (hypophosphatemic vitamin D-resistant): There are insufficient data to support a role of vitamin D in this condition.

• Seasonal affective disorder (SAD): Seasonal affective disorder (SAD) is a form of depression that occurs during the winter months, possibly due to reduced exposure to sunlight. In one study, vitamin D was found to be better than light therapy in the treatment of SAD. Further studies are necessary to confirm these findings.

• Senile warts: In early study, senile warts (a skin condition that generally appears in those over 50 years of age) have been treated with topical vitamin D3.

• Skin pigmentation disorders (pigmented lesions): Application of vitamin D3 ointment on the skin, in combination with intense pulsed-radio frequency, may be beneficial in the treatment of pigmented lesions associated with neurofibromatosis 1 (NF1).

• Tooth retention: Oral bone and tooth loss are correlated with bone loss at sites other than the mouth. Research suggests that intake levels of calcium and vitamin D aimed at preventing osteoporosis may have a beneficial effect on tooth retention.

• Vitamin D deficiency (infants and nursing mothers): High-quality clinical trial evidence suggests that high doses of supplemental vitamin D provided to breastfeeding mothers may improve the vitamin D status of both mother and child. More research is needed to confirm these findings.

• Weight gain (postmenopausal): Vitamin D supplementation (in combination with calcium) may have an effect on postmenopausal weight gain. Evidence suggests this may be particularly true in women consuming inadequate calcium, and this warrants further study.

• Avoid if allergic or hypersensitive to vitamin D or any of its components. Vitamin D is generally well tolerated in recommended doses. Doses higher than recommended may cause toxic effects. Individuals with hyperparathyroidism (overactive thyroid), kidney disease, sarcoidosis (nodule formation in the liver, lymph glands, lungs, and salivary glands), tuberculosis, or histoplasmosis (a fungal infection that affects the lungs) have a higher risk of experiencing toxic effects. Vitamin D is generally considered safe for pregnant women. It may be necessary to give infants vitamin D supplements along with breast milk.

• Vitamin E: Vitamin E exists in eight different forms: alpha-, beta-, gamma-, and delta-tocopherol; and alpha-, beta-, gamma-, and delta-tocotrienol. Alpha-tocopherol is the most active form in humans.

• Allergic rhinitis: Although thought to aid in reducing the nasal symptoms of allergies, vitamin E intake may not be effective. Current evidence is limited, however, and more studies are needed before a firm conclusion can be drawn.

• Altitude sickness: Vitamin E may offer some benefits in exposure to high altitude. Antioxidant supplementation (vitamin E with beta-carotene, vitamin C, selenium, and zinc) may improve some parameters of athletic performance at high altitudes. However, antioxidants may not reduce inflammation after exercise at high altitudes. More research is needed before conclusions can be drawn.

• Amyotrophic lateral sclerosis (ALS): There is unclear evidence of vitamin E for treatment of ALS. More studies are needed before a strong conclusion can be made.

• Anemia: Studies of vitamin E supplementation for anemia have yielded mixed results. Further research is needed before a firm conclusion can be made.

• Angina (chest pain): Vitamin E has been suggested and evaluated in patients with angina, although possible benefits remain unclear. Further evidence is necessary before a clear conclusion can be drawn. Patients with known or suspected angina should be evaluated by a physician.

• Antioxidant: Vitamin E possesses antioxidant activity, but it is not clear if there is any benefit of this property in humans. The American Heart Association has recommended obtaining antioxidants such as vitamin E by eating a well-balanced diet high in fruits, vegetables, and whole grains, rather than from supplements, until further scientific evidence is available.

• Atherosclerosis (hardening of arteries): Vitamin E has been proposed to have a role in preventing or reversing atherosclerosis by inhibiting oxidation of low-density lipoprotein ("bad") cholesterol. Several population studies have suggested that a high dietary intake of vitamin E and high blood concentrations of alpha-tocopherol are associated with lower rates of heart disease. However, while the Cambridge Heart Antioxidant Study supported this hypothesis, the more recent prospective Heart Outcomes Prevention Evaluation (HOPE) study did not. This area remains controversial.

• Bladder cancer: There is preliminary evidence of possible benefits of long-term vitamin E supplementation to reduce the risk of mortality in bladder cancer patients, although additional research is necessary before a clear conclusion can be reached.

• Breast cancer: Vitamin E has been suggested as a possible therapy for the prevention or treatment of breast cancer. Published studies have included measurement of vitamin E levels, laboratory experiments, and population studies. Evidence remains inconclusive, and no clear conclusion can be drawn at this time.

• Breast cancer-related hot flashes: A study of oral vitamin E reported a very small reduction in hot flash frequency (approximately one less hot flash per day), but no preference among patients for vitamin E over placebo.

• Cancer treatment: There is a lack of reliable scientific evidence that vitamin E is effective as a treatment for any specific type of cancer. Caution is merited in people undergoing treatment with chemotherapy or radiation, because it has been proposed that the use of high-dose antioxidants may actually reduce the anticancer effects of these therapies. This remains an area of controversy, and studies have produced variable results. High doses of vitamin E may also cause harm in cancer patients. Patients interested in using high-dose antioxidants such as vitamin E during chemotherapy or radiation should discuss this decision with their medical oncologist or radiation oncologist.

• Cardiovascular disease in dialysis patients: It has been suggested that hemodialysis patients may be under increased oxidative stress and therefore may benefit from the chronic use of antioxidants (particularly for the reduction of risk of heart disease). There is some research on the use of high-dose chronic vitamin E in dialysis patients for heart disease prevention, although benefits or risks remain unclear in this population. Recent concern has been raised that regular use of high-dose vitamin E supplements may actually increase the risk of death (from "all causes") by a small amount, although this remains an area of controversy and active investigation. Additional research is necessary in this area before a firm conclusion can be reached.

• Cataract prevention: There is conflicting evidence regarding the use of vitamin E to prevent cataracts. Although some studies across populations have suggested some protective effects (which may take up to 10 years to yield benefits), other studies in humans have reported a lack of benefits when used either alone or in combination with other antioxidants. Additional research is necessary before a clear conclusion can be reached.

• Chemotherapy nerve damage (neurotoxicity): Like other antioxidants, vitamin E has been suggested as a therapy to prevent complications due to chemotherapy, such as nerve damage (neuropathy). There is some evidence of benefits, for example, when it is used with chemotherapeutic drug cisplatin. However, caution is merited, because it is not known if the use of high-dose antioxidants during chemotherapy may actually reduce the anticancer effects of some chemotherapy agents or radiation therapy. This remains an area of controversy, and patients interested in using antioxidants during chemotherapy should discuss this decision with their oncologists.

• Colon cancer prevention: There is not sufficient scientific evidence to determine if vitamin E prevents colon cancer. In patients with previous colon cancer, a combination of vitamins A, C, and E has been reported to reduce the risk of developing a new colon cancer. Preventive benefits have also been suggested in those with no prior colon cancer when vitamin E is used in a multivitamin but not when used alone. Recent results of the Women's Health Study report no overall reduction in cancer risk with daily use of vitamin E, although this study was not large enough to look at colon cancer specifically. Additional research is necessary in this area before a firm conclusion can be reached.

• Dementia/Alzheimer's disease: Vitamin E has been proposed and evaluated for the prevention or slowing of dementia (including Alzheimer's type), based on antioxidant properties and findings of low vitamin E levels in some individuals with dementia. There is some evidence that all-rac-alpha-tocopherol is similar in efficacy to selegiline (Eldepryl®) and superior to placebo for slowing cognitive function decline in patients with moderately severe Alzheimer's disease, but no additive effect was observed when used in combination with selegiline. Retrospective data suggest that long-term combination therapy with donepezil (Aricept®) may help slow cognitive decline in patients with Alzheimer's disease. Overall, the evidence remains inconclusive in his area. Other research suggests that vitamin E from dietary sources or supplements does not affect the risk of developing Alzheimer's disease or vascular dementia.

• Diabetes mellitus: Vitamin E has been proposed for the prevention of types 1 or 2 diabetes; for the improvement of abnormal sugar control in diabetes; for prevention of platelet dysfunction and atherosclerosis in diabetes; for the correction of vitamin E deficiency in diabetic patients; and for the prevention of diabetic complications of the eye (retinopathy), kidneys (nephropathy), and nervous system (neuropathy). It is not clear that vitamin E is beneficial in any of these areas, and further evidence is necessary before a clear conclusion can be drawn.

• Dysmenorrhea (painful menstruation): There is preliminary evidence of possible benefits of vitamin E supplementation to reduce chronic menstrual pain, although additional research is necessary in this area before a firm conclusion can be reached.

• Glucose-6-phosphate dehydrogenase (G6PD) deficiency: Vitamin E supplementation has been studied for the inherited disorder G6PD deficiency with conflicting evidence. Additional research is necessary before a clear conclusion can be drawn.

• Glomerulosclerosis (kidney disease): It has been suggested that proteinuria (protein in the urine) may be reduced with the use of vitamin E in patients with a kidney disease called focal segmental glomerulosclerosis. However, further research is necessary before a clear conclusion can be drawn.

• Healing after photorefractive keratectomy (laser eye surgery): High-dose vitamin E plus vitamin A (taken by mouth) may improve healing of the cornea and improve visual acuity (sharpness) following laser surgery for vision correction. Animal research suggests that topical vitamin E on the eye may be helpful. Additional research is necessary before this use of vitamin E can be concluded as being safe or effective.

• Hepatitis (hepatitis C): In patients with hepatitis C on antiviral therapy, vitamin E has been proposed to prevent inflammation. More studies are needed to examine the effects of vitamin E in chronic hepatitis.

• High cholesterol: The effects of vitamin E on cholesterol levels and atherosclerosis have been studied in numerous laboratory, population, and clinical trials. It remains unclear if there are clinically meaningful benefits, and it is not known what the effects of vitamin E are compared to (or in combination with) other agents that have been clearly demonstrated as beneficial for lowering lipids. Further research is warranted before a clear conclusion can be drawn.

• Immune system function: Studies of the effects of vitamin E supplementation on immune system function have yielded mixed results. Further research is needed before a clear conclusion can be drawn.

• Intermittent claudication: Multiple studies have evaluated the use of vitamin E in patients with peripheral vascular disease to improve exercise tolerance and intermittent claudication (pain in the legs with walking due to cholesterol buildup in blood vessels). Although some results have been promising, most studies have been small and poorly designed. It remains unclear if vitamin E is beneficial in this condition.

• Macular degeneration (eye disease): Like other antioxidants, vitamin E has been suggested to prevent, slow the progression of, or improve macular degeneration. The scientific evidence in this area is not conclusive, although there is some suggestion that vitamin E may not be beneficial alone. When combined with beta-carotene and vitamin C, vitamin E may not be significantly beneficial. Additional research is necessary before a clear conclusion can be drawn.

• Parkinson's disease: The scientific evidence is inconclusive in this area.

• Premenstrual syndrome (PMS): The scientific evidence is inconclusive in this area.

• Prostate cancer prevention: The role of vitamin E supplementation for the prevention of prostate cancer is controversial. There are numerous laboratory studies that support possible anticancer properties. However, the results of population research and human research have been mixed, with some studies reporting benefits and others finding no effects.

• Respiratory infection prevention: Daily supplementation with vitamin E taken by mouth does not appear to affect the incidence, duration, or severity of pneumonia in elderly nursing home residents. This treatment also does not appear to alter patterns of antibiotic use, although there may be a protective effect against colds (upper respiratory tract infections). Additional research is warranted.

• Seizure disorder: Vitamin E has been evaluated as an addition to other drugs used to prevent seizures, particularly in epilepsy that is not responding well to other treatments. More evidence is needed to make a firm conclusion. The management of seizure disorder should be under medical supervision.

• Steatohepatitis (inflamed liver): There is some evidence suggesting possible benefits in the management of steatohepatitis in children, although further evidence is necessary before a clear conclusion can be drawn.

• Stomach cancer (prevention): Vitamin supplementation has been proposed to reduce the rate of stomach cancer. However, there is some evidence suggesting that vitamin E does not reduce the rates of stomach cancer or precancerous stomach lesions. More research is needed to examine whether vitamin E has any effects on this form of cancer.

• Supplementation in preterm and very-low-birthweight infants: Premature infants are at risk of vitamin E deficiency, particularly when they are born with very low birthweight. There are numerous studies of vitamin E given to premature infants to try to prevent potentially serious complications such as intraventricular hemorrhage (bleeding into the brain), retinopathy (eye damage), or death. The quality of published research is variable and is not clearly conclusive. Premature infants should be under strict medical supervision, and decisions regarding vitamin supplementation should be made in consultation with a neonatologist.

• Tardive dyskinesia (involuntary movements): Vitamin E has been studied in the management of tardive dyskinesia and has been reported to significantly improve abnormal involuntary movements, although the results of existing studies are not conclusive enough to form a clear conclusion. Vitamin E may be more effective in higher doses and in people who have had tardive dyskinesia for fewer than five years.

• Uveitis (inflammation of the eye): Four-month supplementation with vitamin E taken by mouth had no apparent effect on uveitis-associated macular edema (swelling) or visual acuity (sharpness of vision) in limited study. Additional research is necessary before a clear conclusion can be drawn.

• Venous thromboembolism (VTE): Data suggest that supplementation with vitamin E may reduce the risk of VTE in women, and those with a prior history or genetic predisposition may particularly benefit. VTE includes both deep vein thrombosis and pulmonary embolism. Deep vein thrombosis occurs when a blood clot forms in an intact vein. Pulmonary embolism occurs when a blood clot detaches from its site of origin, travels through the bloodstream, and lodges in the lung's arteries.

• Avoid if allergic or hypersensitive to vitamin E. When taken for short periods of time, vitamin E supplementation is generally considered safe when consumed in recommended dosages.

• Vitamin K: Vitamin K is found in green leafy vegetables (such as spinach), broccoli, asparagus, watercress, cabbage, cauliflower, green peas, beans, olives, canola, soybeans, meat, cereals, and dairy products.

• Bleeding disorders (prevention of bleeding or thrombotic (clotting) events in anticoagulant therapy): Agents that block vitamin K, such as warfarin and phenprocoumon, are often used in anticoagulant (anticlotting) therapy. Because dietary intake of vitamin K may affect anticoagulant function, inconsistent levels of vitamin K in the diet may make it difficult to control anticoagulant stability. Some studies suggest that daily, low-dose vitamin K supplementation may help stabilize anticoagulant therapy.

• Osteoporosis prevention: Vitamin K appears to prevent bone loss, and adequate dietary intake is likely necessary to prevent excess bone loss. Elderly or institutionalized patients may be at particular risk, and adequate intake of vitamin K-rich foods should be maintained. Unless patients have demonstrated vitamin K deficiency, there is no evidence that additional vitamin K supplementation is helpful. Some studies show that vitamin K supplements may increase bone mineral density and bone strength, while others show that vitamin K has no effect on bone turnover. However, vitamin K may play a role in the prevention and treatment of glucocorticoid-induced bone loss. Furthermore, vitamin D and calcium supplementation may enhance the beneficial effects of vitamin K. Further research is needed to confirm these results.

• Avoid if allergic to vitamin K. Injection into the muscle or vein should only be done by a healthcare professional. Many serious side effects have occurred after injection. Menadiol (type of vitamin K that is not available in the United States) should be avoided with glucose-6-phosphate dehydrogenase deficiency. Avoid if pregnant or if taking anticoagulants. The American Academy of Pediatrics recommends giving a single vitamin K1 injection into the muscle for all newborns to prevent vitamin K deficiency bleeding (VKDB). However, large amounts of vitamin K may cause serious side effects or death. Vitamin K is generally considered safe for breastfeeding mothers.

• Zinc: Zinc is an essential mineral that is necessary for the functioning of more than 300 different enzymes. It plays a vital role in many biological processes.

• Alopecia (hair loss): A few studies that examined the efficacy of zinc in treating alopecia have reported conflicting results. Additional information is needed before a conclusion can be made.

• Anorexia nervosa: More research is needed to determine if zinc helps treat anorexia nervosa.

• Bad breath: Chewing gum containing zinc or rinsing out the mouth with a solution containing zinc seemed to reduce bad breath in early studies, but more research is warranted.

• Beta-thalassemia (hereditary disorder): Limited evidence suggests that zinc may help increase height in children with beta-thalassemia. More research is warranted.

• Blood disorders (aceruloplasminemia): Data from case reports suggest a potential role for zinc supplementation in aceruloplasminemia, a neurodegenerative disease caused by a gene mutation.

• Boils: In early study, patients with recurrent boils (furunculosis) treated with zinc found that their furuncles did not reappear. Well-designed clinical trials are needed to confirm this potential benefit.

• Burns: Study results of zinc sulfate supplements given to burn victims to increase healing rate have yielded mixed results. Further research is needed before a conclusion can be made.

• Chronic prostatitis (CP): Early studies suggest that zinc supplements taken with antibiotics may be more effective than antibiotics alone in reducing pain, urinary symptoms, quality of life, and maximum urethra closure pressure for patients with chronic prostatitis. Further research is needed to confirm these results.

• Closed head injuries: Early poorly designed studies suggest that zinc supplementation may enhance neurological recovery in patients with closed head injuries. Further research is needed to confirm these results.

• Cognitive deficits (children): Early studies indicate that daily supplementation with zinc may be of limited usefulness for improving cognition in lead-exposed schoolchildren. Further study may be warranted in this area.

• Common cold: There are conflicting results regarding the effect of zinc formulations in treating duration and severity of common cold symptoms.

• Crohn's disease: Early studies of zinc supplements in patients with Crohn's disease have found positive results. Well-designed clinical trials are needed to confirm these results.

• Dandruff: Shampoo containing 1% zinc pyrithione has been shown to reduce dandruff in some people.

• Diabetes (type 1 and type 2): Diabetic patients typically have significantly lower serum zinc levels compared with healthy controls. In early high-quality studies, zinc supplementation for type 2 diabetics may have beneficial effects in elevating serum zinc level and in improving glycemic control that is shown by decreasing HbA1c concentration. Further study is needed before a conclusion can be made.

• Diabetic neuropathy (nerve damage): Oral zinc supplementation may improve glycemic control and severity of peripheral neuropathy. Further research is needed.

• Diaper rash: Zinc may reduce the incidence of diaper rash and have a preventive effect.

• Eczema: There are conflicting data regarding the correlation of zinc serum levels and eczema.

• Exercise performance: Zinc may improve exercise performance in athletes with low serum zinc or zinc deficiencies. Additional evidence is needed.

• Gilbert's syndrome: Gilbert's syndrome is a common, often inherited disorder that affects processing by the liver of the greenish-brown pigments in bile (called bilirubin). Zinc sulfate supplementation seemed to decrease serum unconjugated bilirubin levels in a small study. Well-designed clinical trials are needed to confirm these results.

• Growth (stunted infants): Evidence suggests that supplementation with zinc plus iron (but not with zinc alone) may improve linear growth (length) of stunted infants with low hemoglobin.

• Hepatic encephalopathy: Hepatic encephalopathy is abnormal brain function caused by passage of toxic substances from the liver to the blood. Early high-quality trials of zinc for this indication have yielded conflicting results.

• Hepatitis C viral infection (chronic): Early studies have shown that zinc in combination with interferon or interferon and ribavirin for hepatitis C viral infection patients did not show significant benefits, except for lower incidence of gastrointestinal side effects in one study. Further study may be warranted in this area. Recent high-quality evidence suggests that supplementation with polaprezinc in patients undergoing treatment with pegylated interferon alpha-2b and ribavirin may decrease damage to the liver cells.

• HIV/AIDS: Patients with HIV/AIDS, especially those with low zinc levels, may benefit from zinc supplementation. Some low-quality studies cite reduction in infections, enhanced weight gain, and immune system function, including increased CD4 and CD8 cells. However, other low-quality studies conflict with these findings. Further research is needed before a conclusion can be drawn.

• Hypothyroidism: Case report data suggest zinc supplementation may improve thyroid hormone levels (particularly T3) among women with hypothyroidism.

• Incision wounds: Although zinc is frequently thought to have beneficial effects on incision wound healing, few studies have investigated this use. Further research is needed before a firm conclusion can be made.

• Infertility: Many studies have reported beneficial results of zinc supplements on infertility, as expressed in improved sperm quality and number, although this effect may depend on the cause of infertility. A minor increase in abnormal spermatozoa in subfertile males taking zinc was noted in one study. Additional information is needed before a firm conclusion can be drawn.

• Kidney function: Early studies show potential improvement in uremic patients taking zinc supplements. Further research is needed to confirm these results.

• Kwashiorkor (malnutrition from inadequate protein intake): Short-term zinc supplementation may increase weight gain and decrease infections, swelling, diarrhea, anorexia, and skin ulcers in children with extreme malnourishment.

• Leg ulcers: There are conflicting findings regarding the potential benefit of zinc for healing leg ulcers.

• Leprosy: A few studies have examined the efficacy of zinc treatment in leprosy. Studies of zinc taken by mouth have reported positive results, while one study of topical zinc reported negative results. Further research is needed before a conclusion can be drawn.

• Liver cirrhosis: People with alcoholic liver cirrhosis may be deficient in zinc. Preliminary studies suggest that zinc may benefit these patients. Further evidence is needed to confirm these findings.

• Lower respiratory infections in children: Early evidence suggests that supplementation with zinc may reduce the incidence and severity of lower respiratory infections. More research is needed.

• Macular degeneration: It is unclear if zinc helps prevent age-related macular degeneration. Research results are conflicting.

• Malaria: Results are contradictory for the effect of zinc on malaria symptoms.

• Menstrual cramps: Case report data suggest a possible role for zinc supplementation in menstrual cramps. Additional study is needed to confirm these findings.

• Mortality: Evidence from high-quality studies found no association between zinc supplementation and mortality among children. Additional study is needed in this area.

• Muscle cramps (cirrhosis): The results of one case series suggest that zinc supplementation may improve muscle cramps in patients with cirrhosis. Further research is needed to confirm these results.

• Parasites: More research is needed to determine if zinc helps treat or prevent parasitic infections.

• Poisoning (arsenic): Results from one study show that a combination of spirulina extract plus zinc may be useful for the treatment of chronic arsenic poisoning with melanosis and keratosis. More research is needed to confirm the effects of zinc alone.

• Pregnancy: According to multiple reviews, there is no evidence to suggest that zinc supplementation offers benefits during pregnancy, although there is a possible reduction in labor complications and preterm deliveries. However, results from individual studies suggest a possible benefit of zinc supplementation on blood pressure during pregnancy. Further research is needed before a conclusion can be drawn.

• Psoriasis: There are only a few studies that examine the efficacy of zinc treatment on symptoms of psoriasis, including psoriasis-induced arthritis-like symptoms. One trial noted a reduction in pain and joint swelling. Other studies do not support a role for zinc in alleviating the symptoms of psoriasis. Further, well-designed clinical trials are required to clarify these results.

• Radiation-induced mucositis: Further research is needed to determine if zinc improves mucositis in patients receiving radiation therapy.

• Respiratory disease (respiratory papillomatosis): Evidence from case reports suggests a possible role for zinc supplementation as adjuvant therapy in JORRP. This area warrants further investigation.

• Rheumatoid arthritis: More research is needed to determine if zinc helps improve rheumatoid arthritis.

• Skin damage caused by incontinence: Early evidence suggests that topical zinc oxide oil may help manage perianal and buttock skin damage in incontinent patients. Further research is needed to confirm these results.

• Stomatitis: Zinc sulfate has been studied for the treatment of recurrent aphthous stomatitis (RAS; mouth ulcer). Study results conflict and no clear conclusion can be drawn at this time.

• Taste perception (hemodialysis, cancer): Results from studies investigating the potential role of zinc in treating taste and smell disorders are contradictory.

• Tinnitus: Studies on the efficacy of zinc in treating tinnitus have yielded contradictory results based on subjective findings. Further research is necessary before a conclusion can be drawn.

• Trichomoniasis: Little research is available on the efficacy of zinc for the treatment of trichomoniasis, a sexually transmitted disease (STD).

• Viral warts: Studies have found conflicting results of the effect of zinc on viral warts. Well-conducted studies are needed to clarify these early results.

• Zinc is generally considered safe when taken at recommended dosages. Avoid zinc chloride, since studies have not been done on its safety or effectiveness. Avoid with kidney disease. Use cautiously if pregnant or breastfeeding.

• Fair negative scientific evidence:

• Calcium: Calcium is the most abundant mineral in the human body. To treat calcium disorders, calcium is given in various chelated forms. Chelated calcium has been chemically bonded to another molecule. Calcium citrate is an example of such a preparation. Calcium may also be combined with other substances to form preparations such as calcium lactate, calcium gluconate, or calcium carbonate.

• Vaginal disorders (atrophy, wasting, or thinning of the vaginal tissue): Stopping treatment with topical hormone replacement therapy and switching to treatment with calcium plus vitamin D worsened vaginal atrophy in human research. Increases in painful or difficult intercourse and urinary leaks were reported. Menopausal complaints of hot flashes and night sweats were also worse than before calcium plus vitamin D therapy.

• Avoid if allergic to calcium or lactose. High doses (more than 1,000 milligrams in men and women aged 19-50 years, and more than 1,200 milligrams in individuals older than age 50) taken by mouth may cause kidney stones. Avoid with high levels of calcium in the blood or urine, high levels of parathyroid hormone, bone tumors, digitalis toxicity, ventricular fibrillation (uncoordinated contraction of ventricular cardiac muscle in the heart), kidney stones, kidney disease, kidney failure, high serum phosphate levels, or sarcoidosis (nodule formation in the liver, lymph glands, lungs, and salivary glands). Calcium supplements made from dolomite (sedimentary rock and mineral composed of calcium magnesium carbonate), oyster shells, or bone meal may contain unacceptable levels of lead. Use cautiously in those with low levels of stomach acid (achlorhydria) or irregular heartbeat. Calcium appears to be safe in pregnant or breastfeeding women when used at recommended doses.

• Copper: Copper is a mineral occurring naturally in many foods, including vegetables, legumes, nuts, grains, fruits, shellfish, avocado, beef, and animal organs.

• Neural tube defect prevention: The risk of neural tube birth defects is decreased in women who take folic acid and multivitamins during the periconception period (the time before, including, and immediately after conception). Supplementation with trace elements alone, such as copper, does not appear to prevent these defects.

• Avoid if allergic to copper. Avoid use of copper supplements when recovering from diarrhea, because excess copper may worsen symptoms. Avoid with hypercupremia (excess copper in the blood). Avoid with genetic disorders affecting copper metabolism (e.g., Wilson's disease, Indian childhood cirrhosis, or idiopathic copper toxicosis). Avoid in those with HIV/AIDS. Use caution when using tap water that contains more than 6 milligrams of copper per liter to prepare food or drinks. Use cautiously in those with anemia, joint pain, muscle pain, or those at risk for selenium deficiency. Use cautiously if taking birth control pills.

• Folate (folic acid):Folate occurs naturally in food, and folic acid is the man-made form of this vitamin.

• Down syndrome: One study does not show a protective effect of folic acid on heart anomalies among infants with Down syndrome.

• Lometrexol toxicity: Folic acid supplementation does not seem to reduce toxicity from the cancer drug lometrexol.

• Avoid if allergic to folate or any of the product ingredients. It is recommended that pregnant women consume 600 micrograms daily in order to reduce the risk of birth defects. Folate is likely safe if breastfeeding if consumed at the recommended dietary allowance (RDA) of 500 micrograms daily.

• Iodine:Iodine is an element that the human body needs to make thyroid hormones.

• Kidney problems (kidney cysts): Iodine has been suggested as a possible treatment for kidney cysts, or small, fluid-filled sacs in the kidneys. Early research suggests that povidone-iodine injections after kidney cysts are drained are not effective.

• Visual outcomes in corneal ulceration: Povidone-iodine does not seem to improve visual outcomes in corneal ulceration.

• Supplements should be taken under the supervision of a healthcare provider. There have been reports of severe and even fatal reactions to iodine. Avoid iodine-based products if allergic to iodine. Do not use for more than 14 days. Lugol solution and saturated solution of potassium iodide (SSKI, PIMA) should be avoided in patients with pulmonary edema, bronchitis, known tuberculosis, or hyperkalemia (above normal potassium blood levels), because of potential side effects from excess iodine or potassium. Use cautiously when applying to the skin, because iodine may irritate or burn tissues. Use sodium iodide cautiously in those with kidney failure or gastrointestinal obstruction (blockage in the stomach and intestine). Iodine is safe in recommended doses for pregnant or breastfeeding women. Avoid povidone-iodine (a widely used antiseptic preparation of polyvinylpyrrolidone and iodine) for perianal (around the anus) preparation during delivery. Avoid povidone-iodine for preventing infection after delivery.

• Iron:Iron is an essential mineral.

• Therapy for anemia after orthopedic surgery: Early study reports that iron taken after elective hip or knee replacement surgery does not result in higher hemoglobin (the oxygen-carrying protein in red blood cells) levels after surgery or a faster rate of increase in hemoglobin than placebo.

• Allergic reactions to iron are unlikely. Avoid if allergic to products containing iron. Avoid excessive intake. Avoid iron supplements with blood disorders that require frequent blood transfusions. Use iron supplement cautiously with a history of kidney disease, intestinal disease, heart disease, peptic ulcer disease, enteritis (inflammation of the small intestine), colitis (inflammation of the colon, or large intestine), pancreatitis (inflammation of the pancreas), hepatitis (inflammation of the liver), or alcoholism. Use cautiously if older than 55 years old, as use may increase risk of heart disease. Pregnant or breastfeeding women should consult their healthcare professionals before beginning iron supplementation.

• Magnesium: Magnesium is a mineral nutrient. Good sources of dietary magnesium are green vegetables (such as spinach), whole grains, nuts, legumes, and halibut.

• Athletic performance: Magnesium is involved in several reactions in the body. Therefore, low magnesium levels may affect exercise performance. Some experts suspect that magnesium levels may not be adequate in many people, especially athletes. Many female athletes do not get enough magnesium from the diet, and magnesium is also lost in the urine with exercise. To date, there is not enough evidence that taking magnesium can improve athletic performance. However, it may reduce the stress response to exercise.

• Brain protection (neuroprotection) for premature infants: Premature delivery may result in many adverse effects, including blindness, deafness, cerebral palsy, and other major disabilities in infants. A review did not show a clear benefit of magnesium sulfate therapy for protecting the brain of the preterm fetus. However, the review found a significant trend that prenatal magnesium therapy may improve motor function in early childhood for infants born prematurely.

• Traumatic brain injury: There is not enough evidence to support the use of magnesium salts in patients with acute traumatic brain injuries. Magnesium has also been studied for brain hemorrhage in combination with other agents. However, the results are unclear.

• Avoid in patients with known allergy to magnesium or other products found in magnesium supplements. Magnesium allergy is reported to be extremely rare. Magnesium may cause stomach irritation, nausea, vomiting, diarrhea, decreased skeletal muscle tone, and decreased estrogen levels. High blood levels of magnesium (hypermagnesemia) may cause thirst; drowsiness; low blood pressure; delirium; coma; heart, muscle, and respiratory disorders; and death. Toxic levels of magnesium may cause depression of the central nervous system. Magnesium may increase the risk of bleeding, and caution is advised in patients with bleeding disorders or those who are taking drugs, such as warfarin (Coumadin®), that may increase the risk of bleeding. Dosing adjustments may be necessary. Avoid in patients with kidney disorders and atrioventricular heart block (when the electric signal from the heart's upper to lower chambers is not being sent correctly). Avoid using magnesium as a laxative in patients with stomach disorders. Patients taking antidiabetic agents, blood pressure-lowering agents, or antibiotics (such as fluoroquinolones and cephalosporins) should use magnesium cautiously. Side effects appear to be uncommon with therapeutic doses of magnesium in infants or women who are pregnant or breastfeeding. According to the National Institute of Health's Lactation and Toxicology Database (LactMed), magnesium sulfate and magnesium hydroxide are acceptable to use during breastfeeding.

• Niacin:Niacin (Vitamin B3) is a B-complex vitamin found in many foods such as liver, poultry, fish, nuts, and dried beans.

• Type 1 diabetes mellitus prevention (niacinamide): Niacinamide (not niacin) does not appear to delay the development of diabetes mellitus (type 1). Evidence is mixed and more study is needed in this area.

• Avoid niacin (vitamin B3) if allergic to niacin or niacinamide. Avoid with a history of liver disease, irregular heartbeat, heart disease, blood clotting, bleeding disorders, asthma, anxiety, panic attacks, thyroid disorders, stomach ulcers, gout, or diabetes. Avoid if pregnant or breastfeeding.

• Pantothenic acid (vitamin B5): Pantothenic acid (vitamin B5) is found in many foods, including, meats, liver, kidney, fish, shellfish, chicken, vegetables, legumes, yeast, eggs, and milk.

• Radiation skin irritation: Based on one study, topical (skin) application of dexpanthenol to areas of irradiated skin does not appear to reduce redness, shedding of the outer skin layers, itching, or pain following radiation treatment.

• Avoid if allergic to pantothenic acid or dexpanthenol, which is converted to pantothenic acid in the body. Avoid with gastrointestinal blockage. Pantothenic acid is generally considered safe in pregnant and breastfeeding women when taken at recommended doses.

• Selenium:Selenium is a trace mineral found in soil, water, and some foods. It is an essential element in several metabolic pathways.

• Arthritis (osteoarthritis, rheumatoid arthritis): Selenium-ACE, a formulation containing selenium and vitamins A, C, and E, has been promoted for the treatment of arthritis. Research has failed to demonstrate significant benefits, with a possible excess of side effects compared to placebo.

• Diabetes (prevention): Some studies have suggested that selenium supplementation may help prevent type 2 diabetes by improving glucose metabolism. However, results from the Nutritional Prevention of Cancer (NPC) trial showed increased rates of type 2 diabetes in subjects taking selenium supplements. Although diabetes was not the primary focus of this study, these results indicate a potential risk of selenium supplementation that needs further examination.

• Kashin-Beck osteoarthropathy: Kashin-Beck disease is an osteoarthropathy (disease of the bones and joints) endemic in selenium- and iodine-deficient areas. Preliminary evidence suggests that selenium supplementation does not significantly improve this disease.

• Muscle and joint disorders: Selenium and vitamin supplementation has been studied in patients with Duchenne muscular dystrophy (DMD), myotonic dystrophy, and exercise-induced muscle injury. However, selenium does not appear to improve muscle strength or motor performance in patients with myotonic dystrophy. Despite promising early evidence, selenium supplementation does not appear to affect muscle strength or disease progression in muscular dystrophy.

• Skin cancer (nonmelanoma) prevention: Results from the Nutritional Prevention of Cancer (NPC) trial, conducted among 1,312 Americans over a 13-year period, suggested that selenium supplementation given to individuals at high risk of nonmelanoma skin cancer is ineffective at preventing basal cell carcinoma and actually increases the risk of squamous cell carcinoma and total nonmelanoma skin cancer. Therefore, selenium supplementation should be avoided in individuals at risk or with a history of nonmelanoma skin cancer.

• Hypersensitivity to selenium is unlikely. Avoid individuals with a known allergy or hypersensitivity to products containing selenium. Selenium deficiency may occur in areas where the soil content of selenium is low. Deficiency may affect thyroid function and cause conditions such as Keshan disease. Selenium deficiency is also commonly seen in patients on total parenteral nutrition (TPN) as their sole source of nutrition. Gastrointestinal disorders may decrease the absorption of selenium, resulting in depletion or deficiency.

• Thiamin (thiamine), vitamin B1: Thiamin (thiamine), also called vitamin B1, is a water-soluble vitamin.

• Fractures (hip): Preliminary evidence suggests that supplemental thiamin may not be beneficial for hip fractures.

• Thiamin is generally considered safe and relatively nontoxic, even at high doses. Avoid if allergic or hypersensitive to thiamin. Thiamin appears safe if pregnant or breastfeeding when taken at the recommended dietary allowance of 1.4 milligrams daily.

• Vitamin A: Vitamin A is a fat-soluble vitamin that is needed for vision.

• Chemotherapy adverse effects: Vitamin A supplementation appears to lack effect on chemotherapy-related side effects, including nausea, vomiting, diarrhea, and mouth sores.

• Lung cancer: Vitamin A has been studied as a possible treatment for lung cancer without evidence of benefits. Available evidence suggests that high-dose Vitamin A and beta-carotene may actually increase the risk of adverse effects, especially among alcohol users and smokers.

• Avoid if allergic to vitamin A. intake levels. Use cautiously in those with liver disease or alcoholism. Smokers who consume alcohol and beta-carotene may have an increased risk of developing lung cancer or heart disease. Vitamin A appears safe in pregnant women if taken in recommended doses. Use cautiously if breastfeeding, because the benefits or dangers to nursing infants are not clearly established.

• Vitamin B6: Vitamin B6 (also called pyridoxine) is commonly found in cereal grains, legumes, vegetables (e.g., carrots, spinach, peas, or potatoes), milk, cheese, eggs, fish, liver, meat, and flour.

• Autism: Studies of B6 supplementation alone or in combination with magnesium have not been shown to definitively benefit autism. Autism should be treated by a qualified healthcare provider.

• Stroke reoccurrence: Pyridoxine alone or in combination with B12 and folic acid orally does not seem to be useful for preventing stroke recurrence.

• Some individuals are particularly sensitive to vitamin B6 and may experience side effects at lower doses. Avoid excessive dosing. Vitamin B6 is likely safe when taken by mouth in doses that do not exceed the recommended dietary allowance (RDA).

• Vitamin B12: Vitamin B12 is a water-soluble vitamin and is commonly found in many foods like fish, shellfish, meats, and dairy products. Vitamin B12 helps maintain healthy nerve cells and red blood cells.

• Circadian rhythm sleep disorders: Taking vitamin B12 orally, in methylcobalamin form, does not seem to be effective for treating delayed sleep phase syndrome. Supplemental methylcobalamin, with or without bright light therapy, does not seem to help people with primary circadian rhythm sleep disorders.

• Leber's disease: Vitamin B12 is contraindicated in early Leber's disease, which is a hereditary optic nerve disorder.

• Lung cancer: Preliminary evidence suggests that there may not be a relationship between vitamin B12 status and lung cancer.

• Stroke: In people with a history of stroke, neither high-dose vitamin B12 combinations containing pyridoxine, vitamin B12, and folic acid nor low-dose combinations containing pyridoxine, vitamin B12, and folic acid seem to affect risk of recurring stroke.

• Avoid vitamin B12 supplements if allergic to cobalamin, cobalt, or any other product ingredients. Avoid with coronary stents or Leber's disease (a hereditary condition marked by acute loss of vision). Use cautiously if undergoing angioplasty (mechanical widening of a narrowed or obstructed blood vessel). Vitamin B12 is generally considered safe when taken in amounts that are not higher than the recommended dietary allowance (RDA).

• Vitamin C (ascorbic acid): Vitamin C (ascorbic acid) is a vitamin that is needed to form collagen in bones, cartilage, muscle, and blood vessels.

• Cataracts (prevention/progression): Although early population research suggested a reduction in cataract formation among individuals taking vitamin C for at least 10 years, subsequent research found no reduction in the seven-year risk of age-related cataract formation or progression with the use of daily vitamin C.

• Common cold prevention (general): More than 30 clinical trials that included more than 10,000 participants have examined the effects of taking daily vitamin C on cold prevention. Overall, no significant reduction in the risk of developing colds has been observed. In people who developed colds while taking vitamin C, no difference in severity of symptoms has been seen overall, although a very small significant reduction in the duration of colds has been reported (approximately 10% in adults and 15% in children). Laboratory experiments in which volunteers were infected with respiratory viruses while taking vitamin C have yielded conflicting results, but overall they reported small or no significant differences in symptom severity following infection. Notably, a subset of studies in people living in extreme circumstances, including soldiers taking part in subarctic exercises, skiers, and marathon runners, have reported a significant reduction in the risk of developing a cold of approximately 50%. This area merits additional study and may be of particular interest to elite athletes or military personnel.

• Common cold treatment: Numerous studies have examined the effects of starting vitamin C after the onset of cold symptoms. Overall, no significant benefits have been observed. Initial evidence from one study reports possible benefits with high doses of vitamin C taken at the onset of symptoms, but without additional evidence this remains indeterminate. At this time, the scientific evidence does not support this use of vitamin C.

• Heart disease prevention: Vitamin C does not appear to lower cholesterol levels or reduce the risk of heart attacks. Effects on cholesterol plaques in heart arteries (atherosclerosis) remain unclear, and some studies suggest possible beneficial vasodilation (artery opening) properties. Based on the current scientific evidence, vitamin C is generally not recommended for this use. People at risk of heart attacks should speak with their healthcare provider to consider preventive measures such as aspirin.

• Nutritional support (premature infants): In human study, no significant benefits or harmful effects were associated with vitamin C supplementation throughout the first 28 days of life.

• Vitamin C is generally considered safe in the amounts commonly found in foods. Vitamin C supplements are also generally considered safe in most individuals if taken in recommended doses. Avoid high doses of vitamin C with glucose-6-phosphate dehydrogenase (G6PD) deficiency, kidney disorders or stones, cirrhosis (scarring and poor function of the liver as a result of chronic liver disease), gout, or paroxysmal nocturnal hemoglobinuria (a bleeding disorder). Vitamin C intake from food is generally considered safe if pregnant or breastfeeding. It is not clear if vitamin C supplements in doses higher than dietary reference intake recommendations are safe for pregnant or breastfeeding women. Vitamin C is naturally found in breast milk.

• Vitamin D:Vitamin D is found in many foods, including fish, eggs, fortified milk, and cod liver oil. Vitamin D is made by human skin exposed to sunlight.

• Muscle strength: Cholecalciferol taken by mouth does not appear to increase muscle strength or improve physical performance in healthy older men who are not vitamin D deficient.

• Prostate cancer: There is preliminary evidence based on laboratory and human studies that high-dose vitamin D may be beneficial in the treatment of prostate cancer. However, the induction of hypercalcemia at the doses required to inhibit cancer proliferation have slowed its use in clinical trials. This treatment, including the development of noncalcemic analogs, remains under active investigation. Clear evidence of benefit is not yet available.

• Avoid if allergic or hypersensitive to vitamin D or any of its components. Vitamin D is generally well tolerated in recommended doses. Doses higher than recommended may cause toxic effects. Individuals with hyperparathyroidism (overactive thyroid), kidney disease, sarcoidosis (nodule formation in the liver, lymph glands, lungs, and salivary glands), tuberculosis, or histoplasmosis (a fungal infection that affects the lungs) have a higher risk of experiencing toxic effects. Vitamin D is generally considered safe for pregnant women. It may be necessary to give infants vitamin D supplements along with breast milk.

• Vitamin E:Vitamin E exists in eight different forms: alpha-, beta-, gamma-, and delta-tocopherol; and alpha-, beta-, gamma-, and delta-tocotrienol. Alpha-tocopherol is the most active form in humans.

• Asthma: There is preliminary evidence that vitamin E does not provide benefits in individuals with asthma.

• Cancer prevention (general): Recent evidence from a well-conducted randomized controlled trial (the Women's Health Study) reports no reduction in the development of cancer with the use of natural-source vitamin E taken daily. Previously, there have been laboratory, population, and other human trials examining whether vitamin E is beneficial in preventing various types of cancer, including prostate, colon, or stomach cancer. Results of these prior studies have been variable. At this time, based on the best available scientific evidence and recent concerns about the safety of vitamin E supplementation, conclusions about vitamin E for cancer prevention cannot be made.

• Heart disease prevention: Numerous studies of vitamin E oral supplementation have suggested no benefits in the prevention of cardiovascular disease, and there is recent evidence to suggest that regular use of high-dose vitamin E increases the risk of death (from "all causes") by a small amount. These conclusions have been criticized by some experts. Recently, the Women's Health Study reported a reduction in cardiovascular deaths in women taking vitamin E daily (with 10-year follow-up), but no change in the total death rate or number of heart attacks or strokes. Based on the balance of available scientific evidence and in light of recent safety concerns, chronic use of vitamin E cannot be recommended for this purpose, and high-dose vitamin E should be avoided.

• Osteoarthritis: Vitamin E does not appear to reduce symptoms or prevent cartilage loss in knee osteoarthritis. There is a lack of evidence supporting the use of vitamin E in the management of osteoarthritis.

• Peyronie's disease: One study did not show significant improvement in pain, curvature, or plaque size in patients with Peyronie's disease (PD; a condition marked by scarring and deformity of the penis during erection) treated with vitamin E, propionyl-L-carnitine, or vitamin E plus propionyl-L-carnitine compared with those treated with placebo.

• Retinitis pigmentosa: Vitamin E taken by mouth does not appear to slow loss of vision in people with retinitis pigmentosa and may be associated with more rapid loss of sharpness of vision, although the validity of this finding has been questioned. Until further evidence is available, vitamin E may not be advisable in this condition. Therapy decisions should be under medical supervision.

• Rheumatoid arthritis: Vitamin E, taken by mouth, does not appear to reduce the risk of developing rheumatoid arthritis in women.

• Scar prevention: Application of vitamin E directly to the skin does not appear to reduce surgical wound scarring. Because of a risk of contact dermatitis, or skin reaction, some authors have recommended against the use of this therapy.

• Stroke: Recent evidence from the Women's Health Study suggests that daily vitamin E supplementation does not reduce the risk of stroke. Prior evidence was indeterminate for stroke prevention or stroke recovery. At this time, based on the best available scientific evidence and recent safety concerns, conclusions cannot be made.

• Avoid if allergic or hypersensitive to vitamin E. When taken for short periods of time, vitamin E supplementation is generally considered safe when consumed in recommended dosages.

• Vitamin K:Vitamin K is found in green leafy vegetables (such as spinach), broccoli, asparagus, watercress, cabbage, cauliflower, green peas, beans, olives, canola, soybeans, meat, cereals, and dairy products.

• Hepatocellular carcinoma (recurrent hepatocellular carcinoma prevention): Infection with the hepatitis C virus (HCV) may lead to hepatocellular carcinoma (HCC), a form of liver cancer. So far, the results from clinical studies are unclear and do not indicate any beneficial effects of vitamin K in preventing HCC recurrence.

• Avoid if allergic to vitamin K. Injection into the muscle or vein should only be done by a healthcare professional. Many serious side effects have occurred after injection. Menadiol (type of vitamin K that is not available in the United States) should be avoided with glucose-6-phosphate dehydrogenase deficiency. Avoid if pregnant or if taking anticoagulants. The American Academy of Pediatrics recommends giving a single vitamin K1 injection into the muscle for all newborns to prevent vitamin K deficiency bleeding (VKDB). However, large amounts of vitamin K may cause serious side effects or death. Vitamin K is generally considered safe for breastfeeding mothers.

• Zinc: Zinc is an essential mineral that is necessary for the functioning of more than 300 different enzymes. It plays a vital role in many biological processes.

• Celiac disease: In limited study, oral zinc supplements did not seem to improve the clinical condition of patients with unresponsive celiac syndrome.

• Chronic inflammatory rheumatic disease: Early studies found that zinc supplementation did not seem to benefit patients with chronic inflammatory rheumatic disease.

• Continuous ambulatory peritoneal dialysis (CAPD): Zinc supplementation did not improve the nutritional status in patients on CAPD, based on well-designed research.

• Cystic fibrosis: Zinc supplementation does not seem to affect clinical status, growth velocity, or lung function in children with cystic fibrosis.

• Inflammatory bowel disease: Early studies have found that zinc supplementation does not seem to improve inflammatory bowel disease.

• Pneumonia (children): Studies have found that zinc supplementation does not seem to lessen the duration of abnormally fast breathing, hypoxia (inadequate oxygen), chest indrawing, inability to feed, lethargy, severe illness, or hospitalization in children.

• Zinc is generally considered safe when taken at recommended dosages. Avoid zinc chloride, since studies have not been done on its safety or effectiveness. Avoid with kidney disease. Use cautiously if pregnant or breastfeeding.

• Strong negative scientific evidence:

• Chromium Chromium is an essential mineral required by humans in relatively small amounts. Foods and beverages containing chromium include broccoli, grape juice, whole-wheat breads, potatoes, garlic, basil, beef, orange juice, turkey, red wine, apple, banana, and green beans.

• Obesity/weight loss: Chromium has been studied for its ability to treat obesity, but overall, results have not shown any benefit. Although chromium may help improve lean body mass (by reducing fat and increasing muscle), it does not appear to effect general weight loss.

• Trivalent chromium appears to be safe, because side effects are rare or uncommon. However, hexavalent chromium may be poisonous (toxic). Avoid if allergic to chromium, chromate, or leather. Use cautiously with diabetes, liver problems, weakened immune systems (such as HIV/AIDS patients or organ transplant recipients), depression, Parkinson's disease, heart disease, and stroke. Use cautiously in patients who are taking medications for these conditions. Use cautiously if driving or operating machinery. Use cautiously if pregnant or breastfeeding.

• Folate (folic acid): Folate occurs naturally in food, and folic acid is the man-made form of this vitamin.

• Fragile X syndrome: Folic acid supplementation has been shown not to improve symptoms of fragile X syndrome.

• Avoid if allergic to folate or any of the product ingredients. It is recommended that pregnant women consume 600 micrograms daily in order to reduce the risk of birth defects. Folate is likely safe if breastfeeding if consumed at the recommended dietary allowance (RDA) of 500 micrograms daily.

• Magnesium: Magnesium is a mineral nutrient. Good sources of dietary magnesium are green vegetables (such as spinach), whole grains, nuts, legumes, and halibut.

• Preterm labor contractions: Magnesium has been used for prevention of preterm labor contractions (tocolysis). Available studies have not demonstrated that magnesium is effective for this use. Additionally, it is possible that the use of magnesium for contractions may cause fetal death.

• Avoid in patients with known allergy to magnesium or other products found in magnesium supplements. Magnesium allergy is reported to be extremely rare. Magnesium may cause stomach irritation, nausea, vomiting, diarrhea, decreased skeletal muscle tone, and decreased estrogen levels. High blood levels of magnesium (hypermagnesemia) may cause thirst; drowsiness; low blood pressure; delirium; coma; heart, muscle, and respiratory disorders; and death. Toxic levels of magnesium may cause depression of the central nervous system. Magnesium may increase the risk of bleeding, and caution is advised in patients with bleeding disorders or those who are taking drugs, such as warfarin (Coumadin®), that may increase the risk of bleeding. Dosing adjustments may be necessary. Avoid in patients with kidney disorders and atrioventricular heart block (when the electric signal from the heart's upper to lower chambers is not being sent correctly). Avoid using magnesium as a laxative in patients with stomach disorders. Patients taking antidiabetic agents, blood pressure-lowering agents, or antibiotics (such as fluoroquinolones and cephalosporins) should use magnesium cautiously. Side effects appear to be uncommon with therapeutic doses of magnesium in infants or women who are pregnant or breastfeeding. According to the National Institute of Health's Lactation and Toxicology Database (LactMed), magnesium sulfate and magnesium hydroxide are acceptable to use during breastfeeding.

Safety

• General: Individuals should consult qualified healthcare professionals before making decisions about multivitamin use. The recommended daily amounts of vitamins vary depending on several factors, including a person's age, gender, overall health, sun exposure, and eating habits.

• It is also important that patients tell their healthcare providers if they are taking any multivitamins or dietary supplements, because they may interact with other therapies.

• Side effects: Experts disagree whether multivitamins are necessary if a person is healthy and eats a well-balanced diet. The human body has a limited capacity to use vitamins in its metabolic activities. When vitamins are consumed in excess of the body's normal needs, they may have drug-like effects and may also interfere with the effectiveness of standard medical treatments.

• High doses of fat-soluble vitamins may be especially dangerous because the body stores for future use extra fat-soluble vitamins that are not immediately needed. As a result, these vitamins (vitamins A, D, E, and K) may build up to toxic levels in the body if they are consumed in excessive amounts.

• High doses of vitamin B6 (pyridoxine) are also considered unsafe, because they may cause serious side effects, including nerve damage in the arms and legs.

• High doses of iron may lead to iron toxicity. Most excess iron accumulates in the body instead of being excreted. In children, death may result from consumption of a dose of as little as 200 milligrams. In cases of suspected iron overdose, immediate medical attention is essential. Symptoms of iron toxicity include diarrhea, black stools, nausea, vomiting of blood, liver damage, a metallic taste in the mouth, fluid buildup in the lungs, dehydration, low blood pressure, shock, weak but rapid pulse, shock, chills, coma, convulsions, dizziness, drowsiness, headache, fever, skin flushing, loss of skin color, and bluish-looking lips and fingernails. These symptoms may disappear after several hours but may come back the following day or a few days later.

• Interactions: Some vitamins may interact with other medications. For instance, vitamin K may interfere with blood-thinning drugs (e.g., warfarin) and increase the risk of blood clotting.

• Interference with medical tests: Taking excessive doses of vitamin supplements may cause problems with some medical tests. For example, excessive doses of vitamin C supplements may interfere with a blood glucose test by changing blood glucose levels. Because blood glucose levels are commonly used to diagnose diabetes, patients should tell their healthcare providers if they are taking any multivitamins or dietary supplements.

Author Information

• This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

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