Despite all the marketing hype, they don’t prevent disease and can do harm.
Several studies in recent years — including two new clinical trials and one large review, conducted by the U.S. Preventive Services Task Force, of 27 past clinical trials — have concluded that there’s no evidence to justify taking daily multivitamin and mineral supplements. That’s because the large majority of Americans who take supplements aren’t deficient in vitamins or minerals without them.
"Study after study comes back negative — yet people continue to take supplements, now at record rates," said Edgar Miller, MD, one of five authors of an editorial in the Annals of Internal Medicine, “Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements,” and a professor of medicine and epidemiology at Johns Hopkins University in Baltimore.
People clearly feel that they’re taking better care of themselves if they swallow a pill, but they’re wasting their money, the authors argued, and could even be hurting their health: beta-carotene, vitamin E, and possibly high doses of vitamin A supplements may increase death rates, the researchers said.
Meanwhile, the supplement industry keeps growing. A 2013 Gallup poll reported that half of Americans aged 50 to 64 say they take vitamins or minerals, as do 68 percent of seniors. The most popular supplement is a multi-vitamin. Americans have been taking steadily more of one kind of supplement or another since the late 1980s, the Centers for Disease Control and Prevention reports.
But a growing body of science shows these supplements aren’t helping them. In one study, researchers followed 6,000 male doctors ages 65 and older to see the effect of taking a daily multivitamin over 12 years. The multivitamin was intended to prevent mental decline, but it did no better than placebo.
Focusing on 1,700 people who had already had a heart attack, yet another study examined whether high doses of multivitamins and minerals could prevent another heart attack, a stroke, or death. The supplements hadn’t made a difference five years later.
The large review mentioned earlier analyzed clinical trials that in total included 450,000 older adults, looking for evidence that either multivitamins or other vitamins taken individually or in pairs affected mortality or cancer or heart disease. There wasn’t any.
Customers might be surprised to learn that they’re not even getting what the label promises. When the testing company LabDoor analyzed 75 best-selling multivitamin supplements in the United States, measuring levels of key vitamins (A, B-3, B-6, C, D, and folic acid), and minerals (calcium, iron, magnesium, manganese, phosphorus, potassium, sodium, and zinc), it found that the supplements missed their vitamin label claims by an average of 22.6 percent and missed their mineral label claims by an average of 29.2 percent
Does it matter? Well, let’s say you spend $8 on 60 multivitamins, which comes to 13 cents per pill, and take one a day. Over the year you’ll have spent almost $50 — to give yourself an illusion of better health. For the same price, you could buy a very basic set of weights. Building muscle strength would very likely be good for your well-being, though your workout will take longer than swallowing a pill. With $50, you could get a sports bra with change left over — or be part of the way towards a new pair of high-end sneakers. Maybe you’d prefer a meditation tape. You get the idea. Just about everyone could benefit from more exercise and vegetables and de-stressing. Multivitamins, we don’t need.
September 29, 2015
Christopher Nystuen, MD, MBA