Can calcium supplements cause serious adverse effects in healthy people?

Abstract

Calcium supplements with or without vitamin D increase the risk of myocardial infarction (MI), with numbers needed to harm (NNH) over 5 years of 69 to 240 (strength of recommendation [SOR]: B, meta-analyses of randomized controlled trials [RCTs] that evaluated a predominantly older female population and were limited by study designs). Calcium supplements with or without vitamin D may increase the risk of stroke, with an NNH over 5 years of 283 (SOR: B, meta-analyses of RCTs). Calcium supplementation, but not a diet rich in calcium, also increases the risk of renal calculi, with an NNH over 7 years of 272 (SOR: B, RCT and a cohort study, which also evaluated a predominantly older female population).