Anyone with low levels of vitamin D may be at a higher risk for cardiovascular disease, but the link is even stronger for diabetics, and now scientists are beginning to understand why.

Researchers at Washington University School of Medicine in St. Louis conducted a study which found vitamin D deficiency causes diabetics to be unable to process cholesterol normally. As a result, it builds up in their blood vessels, increasing the risk of heart attack and stroke.

“Vitamin D inhibits the uptake of cholesterol by cells called macrophages,” explains Dr. Carlos Bernal-Mizrachi, a Washington University endocrinologist at Barnes-Jewish Hospital.

“When people are deficient in vitamin D, the macrophage cells eat more cholesterol, and they can’t get rid of it…They become what scientists call foam cells, which are one of the earliest markers of atherosclerosis,” he adds.

Those at risk for high cholesterol may consider eliminating red and processed meats from their diet and replacing them with good sources of omega-3 fatty acids which have proven heart benefits.

Fish such as salmon or mackerel are rich in omega-3, as are nutritional supplements containing fish oil.