Importance Calcium intake has been promoted because of its proposed benefit on bone health, particularly among the older population. However, concerns have been raised about the potential adverse effect of high calcium intake on cardiovascular health.
Objective To investigate whether intake of dietary and supplemental calcium is associated with mortality from total cardiovascular disease (CVD), heart disease, and cerebrovascular diseases.
Results During a mean of 12 years of follow-up, 7904 and 3874 CVD deaths in men and women, respectively, were identified. Supplements containing calcium were used by 51% of men and 70% of women. In men, supplemental calcium intake was associated with an elevated risk of CVD death (RR>1000 vs 0 mg/d, 1.20; 95% CI, 1.05-1.36), more specifically with heart disease death (RR, 1.19; 95% CI, 1.03-1.37) but not significantly with cerebrovascular disease death (RR, 1.14; 95% CI, 0.81-1.61). In women, supplemental calcium intake was not associated with CVD death (RR, 1.06; 95% CI, 0.96-1.18), heart disease death (1.05; 0.93-1.18), or cerebrovascular disease death (1.08; 0.87-1.33). Dietary calcium intake was unrelated to CVD death in either men or women.
Conclusions and Relevance Our findings suggest that high intake of supplemental calcium is associated with an excess risk of CVD death in men but not in women. Additional studies are needed to investigate the effect of supplemental calcium use beyond bone health.