The risk of heart attack may be reduced by taking vitamin D supplements

Research on the cardiac benefits of vitamin D is mixed, with some previous studies suggesting that supplementation does not protect against heart problems. A 2019 analysis published in JAMA Cardiology concluded that vitamin D supplements do not reduce the risk of having or dying from a heart attack or stroke. The findings may prompt further investigation into the role of vitamin D supplementation, particularly in people taking medications to prevent or treat cardiovascular disease.

 

The analysis involved more than 21,000 people aged 60 to 84 years, who were divided into two groups: one group received a monthly capsule containing 60,000 IU of vitamin D, and the other received a placebo. Excluded from the study were people already taking more than 500 IU of vitamin D per day and those with a history of high calcium levels, hyperparathyroidism, kidney stones, osteomalacia of the soft bones, and sarcoidosis. On average, treatment lasted five years, and more than 80% of participants reported taking at least 80% of the study tablets.

 

Major heart problems occurred in 1,336 participants during the study (6.6% in the placebo group versus 6.6% in the vitamin D group). Although the difference between the two groups was relatively small, the rate of major cardiovascular events was 9.9% lower in the vitamin D participants than in the placebo participants. The rate of myocardial infarction was 19% lower in the vitamin D group, and the rate of coronary revascularization was 11% lower. There was no difference between the two groups with respect to strokes.

 

Anastassios G. Pittas, MD, chief of the division of endocrinology at Tufts Medical Center in Boston, says the effect of the dose given to this population was small, but when considered at the public health level, it could have important implications. He points out that in this study, 6 out of 1,000 cardiovascular events were prevented by vitamin D, whereas in general, a threshold for a minimally significant difference in reduction is 20 or 30 fewer per 1,000.

 

In a subgroup analysis, the researchers saw some evidence of a stronger effect in those taking statins or other cardiovascular medications at baseline. Although these results were not statistically significant, Pittas called the effect in this group "interesting" People taking statins and cardiovascular drugs are at higher risk for developing cardiovascular disease, and the intervention could potentially benefit these at-risk groups.