I have previously shared with you that studies have shown a link between calcium supplementation and an increased risk of heart attacks  (myocardial infarction)  and cardiovascular disease in  women and men. The use of calcium supplements to prevent declines in bone mineral density and fractures is widespread in the United States, and thus reports of elevated cardiovascular disease risk in users of calcium supplements are a major public health concern. Any increase in the risk of developing heart disease in CVD risk with calcium supplement use would be of particular concern in individuals with type 2 diabetes (T2D) because of increased risks of CVD and fractures observed in this population. However, a new study,study examining the association between calcium intake and subclinical  heart disease in diabetics not only failed to find an adverse effect for calcium on any measure of calcified plaque, but also uncovered a modest decrease in all-cause mortality over a 9.4 year average period in women who supplemented with the mineral.

The study, described online on August 6, 2014 in the American Journal of Clinical Nutrition involved 720 participants in the Diabetes Heart Study recruited between 1998 and 2005. Questionnaires administered upon enrollment provided information concerning calcium and vitamin D intake from diet and supplements. Calcified atherosclerotic plaque in the coronary and carotid arteries, and abdominal aorta was measured via computed tomography (CT).

The study found did not find an association between any measure of calcified plaque and calcium intake from diet or supplements was observed.  Also, increased calcium intake was not linked to a greater risk of all-cause mortality over follow-up.  Instead, the opposite was found, among women who supplemented with calcium there was a 38% lower adjusted risk of death from all causes over follow-up in association with each 500 milligram increase in calcium evaluated in this study.

“Studies have raised concerns that calcium supplementation may have the unintended negative consequence of increasing cardiovascular disease risk,” authors Laura M. Raffield and her associates observe. “In this study, we did not observe any negative cardiovascular impacts of differing calcium intakes from diet and supplements in contrast to some previous reports. Instead, calcium supplement use was associated with lower all-cause mortality risk in women.”

While this study has different findings, it looked specifically at diabetics and calcium supplementation, there are other well designed studies involving a broader population that indicates otherwise.  For the time being, I’m going to keep my eye out and a close watch on the upcoming studies.  In my opinion, the jury is still out.


Cross-sectional analysis of calcium intake for associations with vascular calcification and mortality in individuals with type 2 diabetes from the Diabetes Heart Study

Two new studies add fuel to the calcium supplement debate