NMA: Nonprescription Medicines Academy

More Evidence of Link Between Calcium Supplements and Myocardial Infarction Risk

August 1st, 2012

Calcium supplements might increase myocardial infarction (MI) risk and should be taken with caution, according to the results of a prospective examination of the associations of dietary calcium intake and calcium supplementation with MI and stroke risk and overall cardiovascular disease (CVD) mortality.

The analysis included data from 23,980 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The participants—all members of the Heidelberg (Germany) cohort—were 35 to 64 years of age and free of major CVD events at recruitment. Information about dietary intake of calcium came from a self-administered food frequency questionnaire; energy-adjusted calcium intakes were categorized into quartiles using sex-specific cut-off points. Information about use of calcium supplements came from a baseline interview and follow-up questionnaire surveys.

A total of 354 MI cases, 260 stroke cases, and 267 CVD deaths were documented in the study population after an average follow-up time of 11 years. Compared with participants in the lowest quartile of total dietary calcium intake, participants in the third quartile had a significantly reduced risk of MI (HR, 0.69; 95% CI, 0.50–0.94); none of the other comparisons were statistically significant. In addition, no statistically significant associations were found for either stroke risk or overall CVD mortality. In comparison with participants who did not use any supplements, users of calcium supplements had a significantly increased MI risk (HR, 1.86; 95% CI, 1.17–2.96), which was more pronounced for participants who used only calcium supplements without any other vitamins or minerals (HR, 2.39; 95% CI, 1.12–5.12).

To the best of the authors’ knowledge, this is the first observational study to report a possible adverse effect of calcium supplements on MI risk. Two previous reports of a possible adverse effect were associated with meta-analyses.

Heart. 2012;98:920-5.