RT Journal A1 Larsson SC T1 Are calcium supplements harmful to cardiovascular disease?: Comment on “ dietary and supplemental calcium intake and cardiovascular diseases mortality: the national institutes of health–aarp diet and health study” JF JAMA Internal Medicine JO JAMA Internal Medicine YR 2013 FD April 22 VO 173 IS 8 SP 647 OP 648 DO 10.1001/jamainternmed.2013.3769 UL http://dx.doi.org/10.1001/jamainternmed.2013.3769 AB Calcium is the most abundant mineral in the body and is crucial for the maintenance of strong bones and teeth. Furthermore, calcium is required for the body's basic functions, such as nerve transmission, blood clotting, blood pressure, muscle contraction, enzyme activation, and hormone regulation. Although when most people think of calcium they think of dairy sources, nondairy foods, such as spinach, kale, soybeans, and white beans, also contain calcium. Calcium is available as dietary supplements and is often taken in combination with vitamin D to improve calcium absorption. Many women are encouraged to take calcium supplements. Approximately 43% of the US population uses dietary supplements that contain calcium.1 Given the extensive use of calcium supplements, any beneficial or harmful effect of supplemental calcium on health is of great clinical and public health importance.