Deeper Dive: Do I have to choose between osteoporosis and heart disease?

Approximately 54 million Americans have osteoporosis, a debilitating disease that causes a loss of bone density and mass and increases the risk of fracture. Guidelines from several organizations, including the U.S. National Osteoporosis Foundation^[1], recommend dietary calcium intake of at least 700 milligrams per day for the prevention and treatment of osteoporosis for adults 50 years and older. The U.K. National Osteoporosis Guideline Group advocates the use of supplements to promote optimal bone health for people who do not eat the recommended intake of calcium through dietary sources.

However, there may be a downside to higher calcium intake. In the early 2010s, evidence emerged that calcium supplementation may cause an increased risk of cardiovascular disease^[2] (CVD), a group of disorders of the heart and blood vessels that includes coronary heart disease (CHD, a disease of blood vessels supplying the heart muscle) and cerebrovascular disease (a disease of the blood vessels supplying the brain).

However, later studies found that calcium supplementation did not increase^[3] the risk of CHD. Based on the results of a 2016 meta-analysis and systematic review^[4] showing no significant difference in risk of CVD events or mortality between calcium supplementation (with or without vitamin D) and placebo groups, the National Osteoporosis Foundation and the American Society for Preventive Cardiology^[5] issued a clinical guideline that there is moderate quality evidence that calcium intake, with or without vitamin D, from food or supplements does not increase the risk of CVD in healthy adults.

Given the conflicting findings from studies on this subject, the authors of the study under review aimed to investigate the associations between calcium supplementation and the risk of CVD through a comprehensive meta-analysis of placebo-controlled double-blind RCTs and subgroup analyses that addressed the controversial findings from previous studies. They also evaluated the differences in findings and study characteristics of previous systematic reviews and meta-analyses versus the current study.

Professional health organizations stress the importance of an adequate amount of calcium for the prevention and treatment of osteoporosis, and supplementation has been recommended if dietary intake is insufficient. There is conflicting evidence regarding the risk of CVD associated with calcium supplementation. The purpose of this study was to evaluate the association between calcium supplementation and the risk of CVD.