A new study published in the Journal of the American Medical Association Cardiology has revealed that vitamin D supplements did not decrease the incidence of heart attacks, strokes or other major adverse cardiovascular events.
This contradicts previous research that suggested a link between low levels of vitamin D in the blood and an increased risk of cardiovascular disease.
The researchers from Michigan State University said the findings were consistent for both men and women and for patients of different ages.
“We thought it would show some benefit, it didn’t show even a small benefit. This was surprising.” said Mahmoud Barbarawi, a clinical instructor in the MSU College of Human Medicine.
Many earlier studies have found an association of low levels of vitamin D in the blood and an increased risk of cardiovascular disease, suggesting that vitamin D supplements might reduce that risk.
The researchers reviewed data from 21 clinical trials, including more than 83,000 patients. Half the patients were administered vitamin D supplements, and half were given placebos. The meta-analysis of data showed no difference in the incidence of cardiovascular events or all causes of death between the two groups.
While some studies have found a link between low levels of the vitamin and an increased risk of adverse cardiovascular events, the new suggests that other factors, such as outdoor physical activity and nutritional status, might explain the association.
Vitamin D sometimes is known as the sunshine vitamin, because human skin makes vitamin D when exposed to the sun. Thus, those living farthest from the equator tend to have lower levels of vitamin D in their blood.