Calcium Supplements Linked to Heart Attack Risk

Study suggests supplements, but not dietary calcium, raise heart attack risk.

ByABC News
May 23, 2012, 11:42 AM

May 24, 2012— -- Taking calcium supplements to build stronger bones may be bad for the heart, according to a new study that suggests getting similar doses from calcium-rich foods is a safer alternative.

The study, which followed nearly 24,000 German men and women between the ages of 35 and 64, found those who regularly took calcium supplements were 86 percent more likely to have a heart attack than those who did not. Study subjects who relied completely on supplements for their daily calcium intake were 139 percent more likely to have a heart attack.

"Calcium supplements, which might raise [heart attack] risk, should be taken with caution," the authors wrote in their report, published Wednesday in the journal Heart.

Calcium is critical for strong bones and teeth. But the new study suggests supplements, many of which are sold as tasty gummy candies and chocolates, are no replacement for healthy foods.

"Calcium supplements have been widely embraced by doctors and the public on the grounds that they are a natural and therefore safe way of preventing osteoporotic fractures," Ian Reid and Mark Bolland of the University of Auckland in New Zealand wrote in an editorial accompanying the study. "It is now becoming clear that taking this micronutrient in one or two daily [doses] is not natural, in that it does not reproduce the same metabolic effects as calcium in food."

Adult men and women should consume between 1,000 and 1,200 milligrams of calcium daily, according to the National Institutes of Health. For most Americans, that's a cup of yogurt, a glass of milk and a slice of cheese. For nondairy dieters, a bowl of enriched cereal, a glass of fortified orange juice, half a cup of tofu and a slice of salmon will do the trick.

But some people, such as post-menopausal women, struggle to get enough calcium from food alone and turn to supplements for a boost. More than 60 percent of women over 60 take calcium supplements, up from 28 percent two decades ago according to a 2011 report from the U.S. Centers for Disease Control and Prevention's National Center for Health Statistics.

"We should return to seeing calcium as an important component of a balanced diet, and not as a low cost panacea to the universal problem of postmenopausal bone loss," wrote Reid and Bolland, who in 2011 linked calcium supplements to an increased risk of heart attack in post-menopausal women.

Supplements have been the topic of growing scrutiny, with a 2011 study linking the nutrient-packed pills to an increased risk of early death in older women.

"The assumption should not be that they can't hurt and might help," Dr. Harlan Krumholz, associate professor of medicine at Yale University School of Medicine told ABC News. "We should all want strong evidence of benefit and assurance of safety before making choices to take supplements."