Vitamin D, Calcium Supplements, and Implications for Cardiovascular Health

Vitamin D and calcium supplements are commonly used, often together, to optimize bone health. Multiple observational studies have linked low serum 25-hydroxyvitamin D concentrations with increased cardiovascular risk. However, subsequent randomized controlled trials (RCTs) failed to demonstrate cardiovascular benefit with vitamin D supplementation. Although vitamin D supplements do not appear to be harmful for cardiovascular health, the lack of benefit in RCTs should discourage their use for this purpose, favoring optimizing vitamin D status through healthy lifestyles such as specific foods and modest sunlight exposure. Furthermore, some (but not all) observational and RCT studies of calcium supplementation have suggested potential for cardiovascular harm. Therefore, calcium supplementation should be used cautiously, striving for recommended intake of calcium predominantly from food sources. In this review, the authors examine the currently available evidence investigating whether vitamin D and calcium supplements are helpful, harmful, or neutral for cardiovascular health.