The study, published in the British Medical Journal (doi: 10.1136/bmj.c3691), indicates that calcium supplements may cause more cardiovascular events (such as heart attacks and stroke) than the number of fractures they prevent.
The meta-analysis was led by Professor Ian Reid at the University of Auckland and included fifteen randomized trials on calcium supplements conducted in the last twenty years, with the aim to investigate the links between calcium supplementation and cardiovascular events.
In light of the “public interest and media reports […] Health Canada has reviewed this study, its strengths and limitations, and determined that it does not demonstrate a conclusive association between calcium supplementation and cardiovascular risks. We will continue to evaluate new data as they emerge and will take appropriate action as necessary, including informing Canadians,” said the regulator.
Calcium supplements are commonly taken by older people as a measure to reduce the effects of osteoporosis. The widely used supplements have been shown to marginally reduce the risk of fracture for osteoporosis sufferers and improve bone density, but very little research has been compiled on the risks of calcium supplementation.