Effect of calcium supplements on risk of myocardial infarction and cardiovascular events
Osteoporosis is a major cause of morbidity and mortality in older people. Calcium supplements marginally reduce the risk of fracture, and most guidelines recommend adequate calcium intake as an integral part of the prevention or treatment of osteoporosis. Consequently, calcium supplements are commonly used by people over the age of. Observational studies suggest that high calcium intake might protect against vascular disease, and the findings are consistent with those of interventional studies of calcium supplements that show improvement in some vascular risk factors. In contrast, calcium supplements accelerate vascular calcification and increase mortality in patients with renal failure, in both dialysis and predialysis populations. Furthermore, a five year randomized controlled trial of calcium supplements in healthy older women, in which cardiovascular events were prespecified as secondary end points, recently reported possible increases in rates of myocardial infarction and cardiovascular events in women allocated to calcium. We carried out a meta-analysis of cardiovascular events in randomised trials of calcium supplements.
In this report we will be discussing the effect of calcium supplements on risk of myocardial infarction and cardiovascular events, 15 studies were included. Overall, 190 potentially relevant reports of studies were identified from the initial searches, but only the 15 studies were eligible for analysis. Thirteen studies compared calcium supplements with placebo, one study had a 2×2 factorial design allowing comparison of calcium with placebo and calcium plus vitamin D with vitamin D,28 and one study compared calcium plus alendronate with alendronate.