PURPOSE: The current literature on the effects of calcium supplementation on cardiovascular health is reviewed. SUMMARY: A comprehensive literature search identified reports on 13 observational studies and 9 clinical trials pertaining to calcium supplement use and the risk of adverse outcomes such as cardiovascular disease (CVD), myocardial infarction (MI), and stroke; cardiovascular events were not primary endpoints of any of the reviewed studies, most of which focused on the effects of calcium use on bone health. Several large cohort studies by researchers in Australia, France, Germany, Sweden, the United Kingdom, and elsewhere have found no significant associations between moderate calcium supplementation and adverse cardiovascular outcomes in otherwise healthy individuals; in some studies, calcium use appeared to confer preventive benefits. However, evidence from other studies suggests that increased calcium supplementation may be associated with an increased risk of MI, as well as a possible link between elevated serum calcium levels and carotid artery plaque buildup. In general, the studies of calcium use and cardiovascular health published to date have had important limitations (e.g., small samples, homogeneous study populations, reliance on self-reported data, lack of or inadequate controlling for established CVD risk factors), and the findings should be interpreted with caution. CONCLUSION: The results of studies on the influence of calcium supplements on the cardiovascular system have been varied. Overall, the benefits of calcium supplementation, including the positive effects on bone health, appear to outweigh the theoretical risk of increased cardiovascular events.