A mendelian randomization study concluded that a genetic predisposition to higher serum calcium levels was associated with increased risk of coronary artery disease (CAD) and myocardial infarction (MI). The study included 60 801 CAD cases (approximately 70% with MI) and 123 504 noncases, with baseline data collected from 1948 and populations derived from across the globe. Six single-nucleotide polymorphisms (SNPs) related to serum calcium levels and without pleiotropic associations with potential confounders were estimated to explain about 0.8% of the variation in serum calcium levels. In the inverse-variance weighted meta-analysis (combining the estimates of the 6 SNPs), the odds ratios per 0.5-mg/dL increase (about 1 SD) in genetically predicted serum calcium levels were 1.25 for CAD and 1.24 for MI. The findings are consistent with observational studies and evidence from randomized clinical trials indicates that calcium supplementation may increase the risk of MI. Source: http://jamanetwork.com/
