Calcium supplements may be harming your heart, not preventing osteoporosis.
While calcium is necessary for strong bones, healthy teeth, and preventing osteoporosis, calcium supplements may be too much of a good thing.
Research conducted at Johns Hopkins University found that taking calcium supplements may cause vascular damage and increase your risk of developing heart disease.
Researchers studied the calcium intake of 2,742 men and women between the ages of 45 and 82. A 120-part questionnaire about participants’ dietary habits was used to rank their calcium from food sources such as dairy products and leafy greens, as well as their use of calcium supplements. They were also scored on whether they had any coronary artery calcification, a condition strongly associated with the development of heart disease. At the beginning of the study, none of the participants had been diagnosed with cardiovascular disease.
After 10 years, participants were again assessed for their calcium intake and their levels of coronary artery calcification to determine whether there was any noticeable link between calcium levels and a risk of coronary artery calcification, which would indicate an increased likelihood of cardiovascular disease.
To analyze their data, researchers split the study’s subjects into five groups based on their calcium intake. The 20 percent of participants with the highest calcium intake consumed over 1,400 milligrams per day, while the 20 percent with the lowest calcium intake consumed fewer than 400 milligrams per day. The data was then adjusted for factors that could influence participants’ risk of developing heart disease, such as age, sex, smoking, exercise, education, and weight.
Researchers initially found that high levels of calcium were a good thing. The group with the highest total calcium intake was 27 percent less likely to develop cardiovascular disease, as indicated by their coronary artery calcification test, than the group with the lowest calcium intake. Consuming a lot of calcium, the results seemed to indicate, lowered a person’s risk of heart disease.
However, when the data was adjusted to compare participants who only consumed calcium from food versus the 46 percent of participants who took supplements, a different result emerged.
Participants who took calcium supplements were 22 percent more likely to have elevated scores of coronary artery calcification, indicating that they were at greater risk for developing heart disease than those who only consumed dietary calcium.
The study’s authors noted that this result could be due to how the human body processes calcium. Dietary calcium is broken down and used to build bones, teeth, and other parts of your body. Calcium from supplements, however, is rarely incorporated into bones and other cells. It remains unused in your body, leading to higher levels of calcification, including coronary artery calcification.
These finding affect a large portion of the adult population. According to the Centers for Disease Control and Prevention, about 370,000 men and women die from coronary heart disease every year, and all forms of heart disease account for one in every four deaths in the United States. And about 43 percent of adults in the United States take calcium supplements, including more than 50 percent of women over age 60, often to decrease their risk of osteoporosis.
“Because of the widespread awareness and treatment of osteoporosis with calcium supplements among older adults,” the study concludes, “this population would appear to be at greater risk of developing the adverse consequences of positive calcium balance, including vascular calcification.”
But, though the study’s authors cautioned against use of calcium supplements, they encouraged a high intake of dietary calcium in adults. “Our findings,” they wrote, “should reassure individuals who are following dietary calcium recommendations by eating highcalcium foods that consuming calcium from diet alone at these levels or higher is not associated with incident coronary artery calcification.”
January 25, 2017
Janet O’Dell, RN