PhotoMany seniors take calcium supplements hoping to help their bones withstand the wear and tear of aging. But a new, large-scale study finds that men may be paying a high price for any benefits they derive from the supplements.

The study found that a high intake of supplemental calcium appears to be associated with an increased risk of cardiovascular disease (CVD) death in men but not in women. The study looked at more than 388,000 participants between the ages of 50 and 71 years, according to a report published Online First by JAMA Internal Medicine, a JAMA Network publication.

Calcium supplements are known to be beneficial in preventing and treating osteoporosis -- a disorder much more common in women than men -- but the researchers noted that other than that, the health effect of calcium supplements remains largely unknown and has become “increasingly contentious.”

The researchers -- Qian Xiao, Ph.D., of the National Cancer Institute, Bethesda, Md., and colleagues -- studied 388,229 men and women ages 50 to 71 years from the National Institutes of Health-AARP Diet and Health Study in six states and two metropolitan areas from 1995 through 1996. 

“In this large, prospective study we found that supplemental but not dietary calcium intake was associated with an increased CVD mortality in men but not in women,” the authors conclude.

“Whether there is a sex difference in the cardiovascular effect of calcium supplement warrants further investigation. Given the extensive use of calcium supplement in the population, it is of great importance to assess the effect of supplemental calcium use beyond bone health,” the authors said.

During an average 12 years of follow-up, 7,904 CVD deaths in men and 3,874 CVD deaths in women were identified and supplements containing calcium were used by 51 percent of men and 70 percent of women. Compared with non-supplement users, men with an intake of supplemental calcium of more than 1,000 mg/day had an increased risk of total CVD death, more specifically with heart disease, but not significantly with cerebrovascular disease death.

For women, supplemental calcium intake was not associated with CVD death, heart disease death or cerebrovascular disease death. Dietary calcium intake also was not associated with CVD death in men or women.

Alternatives for consumers

While the jury is still out on the relative safety of calcium supplements, scientists stressed that consuming calcium-rich foods -- rather than pills -- is a safer way to get bone-building calcium.

“[A] safe alternative to calcium supplements is to consume calcium-rich foods, such as low-fat dairy foods, beans and green leafy vegetables, which contain not only calcium but also a cocktail of essential minerals and vitamins,” said Susanna C. Larsson, Ph.D., of the Karolinska Institutet, Stockholm, Sweden, in a commentary that accompanied the study.

“These non-dairy food sources of calcium have the added health benefits and have recently been reported to improve glycemic control in persons with diabetes. The paradigm ‘the more the better’ is invalid for calcium supplementation.”

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