Calcium supplements are widely taken by women for bone health and some studies have suggested that calcium supplements bring with them an increased risk of cardiovascular disease.

A new study
examined supplemental calcium use and incident cardiovascular disease in a prospective cohort study of 74,245 women in the Nurses' Health Study. The women did not have cardiovascular disease or cancer at the start of the study. They were followed for 24 years to document risk of developing heart attack and stroke.

Calcium supplement intake was assessed every four years and the results, according to researchers at Brigham and Women's Hospital, were that calcium supplement intake did not increase risk of cardiovascular disease in women. Instead, women who take them were actually healthier, though obviously that could be to a healthier lifestyle in numerous ways. 

"Our study has several distinct strengths compared to prior studies including the large number of participants, long-term follow-up, large number of cardiovascular events that were confirmed by medical record review, detailed information about diet and other cardiovascular disease risk factors, and repeated assessment of calcium supplement use over the 24-year follow up period," said Julie Paik, MD, MPH, BWH Channing Division of Network Medicine, Department of Medicine, lead study author.

The researchers found that at the start of the study, women who took calcium supplements had higher levels of physical activity, smoked less, and had lower trans fat intake compared to women who did not take calcium supplements. During the 24 years of follow-up, there were 2,709 heart attacks and 1,856 strokes.

"Based on our findings, additional prospective cohort studies examining potential cardiovascular disease risk associated with calcium supplement use are needed," said Paik. "Future randomized trials of calcium supplementation, if conducted, should be designed to optimize assessment of cardiovascular events."