Nutraceutical: Calcium
 
Indication: Cardiovascular events
 
Source:BMJ April 19, 2011;342:d2040. doi: 10.1136/bmj.d2040.
 
Research: Researchers set out to investigate the effects of personal calcium supplement use on cardiovascular risk in the Women’s Health Initiative Calcium/Vitamin D Supplementation Study (WHI CaD Study), using the WHI dataset, and to update the recent meta-analysis of calcium supplements and cardiovascular risk. The purpose was the reanalysis of the WHI CaD dataset and incorporation in the meta-analysis with eight other studies. The data source in the WHI CaD Study included a 7-year, randomized, placebo-controlled trial of calcium and vitamin D (1 gram calcium and 400 IU vitamin D daily) in 36,282 community dwelling postmenopausal women. Main outcome measures included incidence of four cardiovascular events and their combinations (myocardial infarction, coronary revascularization, death from coronary heart disease, and stroke) assessed with patient-level data and trial-level data.
 
Results: In the WHI CaD Study there was an interaction between personal use of calcium supplements and allocated calcium and vitamin D for cardiovascular events. In meta-analyses of three placebo-controlled trials, calcium and vitamin D increased the risk of myocardial infarction, stroke and the composite of myocardial infarction or stroke. In meta-analyses of placebo-controlled trials of calcium or calcium and vitamin D, complete trial-level data were available for 28,072 participants from eight trials of calcium supplements and the WHI CaD participants not taking personal calcium supplements. In total, 1384 individuals had an incident myocardial infarction or stroke. Calcium or calcium and vitamin D increased the risk of myocardial infarction and the composite of myocardial infarction or stroke. These findings led researchers to conclude that supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction, a finding obscured in the WHI CaD Study by the widespread use of personal calcium supplements. As a result, they believe a reassessment of the role of calcium supplements in osteoporosis management is warranted.