Effects of calcium supplementation on the risk of myocardial infarction.

A paper in the BMJ July 29 2010 gathers in a meta-analysis the results of 15 clinical trials concerning   the consequences of calcium supplementation on the risk of cardiovascular events; the population tested was about 90% women over 60 years. Overall the risk of myocardial infarction appeared 1,3 times higher in people taking a calcium supplementation of 500 mg daily or more, compared to those which did not take any, but the increase in stroke and total mortality was not statistically significant.

However, these results concern only calcium supplementation without vitamin D, which restricts its generalization because usually a combined supplementation of calcium + vitamin D is used.

These results, modest increase in the myocardial infarction risk and a tendency to an increase in overall mortality, are an incitement for moderating calcium prescription or better to reduce its dosage. But there are many discordant data, see this analysis, this one, and this other for example.