It’s well established that everyone needs calcium to promote and support strong bones and teeth, and we are often reminded that calcium supplements are a way to get a sufficient amount of this important mineral. New research, however, suggests calcium supplements can increase the risk of heart attack, and that calcium in the diet may not provide cardiovascular protection as has been suggested in previous studies.
Over the past few years, research into the risks and benefits of calcium have revealed that beyond bone health, dietary calcium and calcium supplements can have a positive role in lowering the risk of high blood pressure, obesity, and type 2 diabetes. On the downside, however, research has uncovered an increased risk of prostate cancer associated with calcium, especially the use of calcium supplements.
Now there’s another warning regarding the use of calcium supplements, and this one is based on the findings of nearly 24,000 individuals who participated in one arm of the European Prospective Investigation into Cancer and Nutrition (EPIC) study. All the subjects shared information about their diet and use of supplements for one year, and their health was then tracked for an average of 11 years.
Based on the number of heart attacks, strokes, and deaths that occurred during the follow-up period and the dietary and supplement information, the investigators reported that individuals whose diets and supplement use included a moderate amount (820 mg daily) of calcium had a 31% lower risk of having a heart attack when compared with subjects who were in the bottom 25% of calcium intake.
However, participants who took calcium supplements regularly were 86% more likely to experience a heart attack than individuals who did not take any supplements at all. The risk of heart attack was even higher among individuals whose only supplement use was calcium: they were more than twofold as likely to have a heart attack as participants who didn’t take any supplements at all.
The take-home message from this study, according to the authors, is that “increasing calcium intake from diet might not confer significant cardiovascular benefits, while calcium supplements, which might raise [heart attack] risk, should be taken with caution.”
Bolland MJ et al. Calcium supplements with or without vitamin D and risk of cardiovascular events: reanalysis of the Women’s Health Initiative limited access dataset and meta-analysis. BMJ, 2011; 342 (apr19 1): d2040