Studies suggesting calcium supplements may increase heart disease risk

The following papers include a number of randomized trials in which calcium supplements increased the risk of cardiovascular disease events, including heart attacks:

Bolland MJ, Grey A, Avenell A, Gamble GD, Reid IR. 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 Apr 19;342:d2040.

Bolland MJ ,Barber PA ,Doughty RN ,Mason B ,Horne A ,Ames R ,et al. Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial. BMJ 2008;336:262

Li S, Na L, Li Y, Gong L, Yuan F, Niu Y, Zhao Y, Sun C. Long-term calciumĀ supplementation may have adverse effects on serum cholesterol and carotid intima-media thickness in postmenopausal women: a double-blind, randomized, placebo-controlled trial. Am J Clin Nutr. 2013 Nov;98(5):1353-9.

Bolland M.J., Avenell A., Baron J.A. et al. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ 2010; 341:c3691.