A number of clinical trials have revealed that there is a 30% increase in the number of heart attacks in individuals whom consume calcium supplements. In addition, these studies suggested that this can be fatal.

Moreover, individuals with an intake of 805mg or more of calcium prior to calcium supplementation may also be at risk of cardiovascular illnesses. A second study conducted by the same researchers (Bolland et al 2010) evaluated the intake of calcium and vitamin D. As suggested by the previous study, calcium increased the risk of cardiovascular diseases such as myocardial infarctions whereas vitamin D had no significant influence on cardiovascular diseases.

A 2012 study conducted on males and females aged between 35-64 consuming calcium supplementation found an increased risk of myocardial infarctions. In addition, individuals consuming supplementations of calcium and other vitamins/minerals carried an 86% chance to have a myocardial infarction during the 11 year study which included 23,980 participants. Moreover, the likelihood of a myocardial infarction significantly increases to 139% in those individuals whom only took calcium alone. The association between death from cardiovascular diseases (CVD) and multivitamin/calcium supplementations were recognised as a concern.

One possible explanation is that high calcium supplementation can increase serum calcium which in turn increases the risk of artery plaque thickness and aortic calcification and concomitant myocardial infarction.

It is important to note that there no risk to health through obtaining Calcium from a healthy diet; it is the Calcium supplementation that poses a risk of cardiovascular illnesses. However, several CAM practitioners and some Integrative medicine doctors prescribe calcium supplements, so is this a dangerous practice?