Getting more vitamin D may lower heart disease risk among individuals with darker skin

UNIVERSITY PARK, Pa. — Making sure you’re getting enough vitamin D may be a simple way to lower heart disease risk, especially among individuals with darker skin. That’s the main finding of a new study by researchers Penn State University. Study authors investigated the links between skin pigmentation, vitamin D, and heart health to reach these conclusions.

The Penn team theorizes vitamin D deficiencies may somewhat explain the particularly high rate of heart disease among African-Americans.

“More darkly-pigmented individuals may be at greater risk of vitamin D deficiency, particularly in areas of relatively low sun exposure or high seasonality of sun exposure,” says S. Tony Wolf, PhD, a postdoctoral fellow at the Penn State and the study’s lead author, in a media release. “These findings may help to explain some of the differences that we see in the risk for developing blood vessel dysfunction, hypertension and overt cardiovascular disease between ethnic groups in the United States. Although there are many factors that contribute to the development of hypertension and cardiovascular disease, vitamin D supplementation may provide a simple and cost-effective strategy to reduce those disparities.”

How does vitamin D relate to heart health?

Whether or not an individual should consider taking a vitamin D supplement depends on a number of factors, researchers say. Examples of such considerations include your age, where you live, how much time you spend in the sun, and skin pigmentation.

Expanding on that last factor a bit further, darker skin contains more melanin. However, that’s actually a negative from a vitamin D perspective; melanin can inhibit the absorption of vitamin D by our skin. So, it’s harder for individuals with more melanin to absorb vitamin D from the sun’s rays.

To research this topic, study authors measured skin pigmentation, vitamin D, and nitric oxide activity within the small blood vessels just beneath the skin among 18 heathy adults (of varying skin tones). For reference, nitric oxide is quite important for blood vessel function, and low levels have a link to an increased risk of both hypertension and cardiovascular disease. Moreover, vitamin D has been shown to help promote nitric oxide availability.

Overall, the study finds adults with darker skin showed lower vitamin D levels and lower nitric oxide availability. Also, lower vitamin D levels were related to reduced nitric oxide-mediated blood vessel function.

“Vitamin D supplementation is a simple and safe strategy to ensure vitamin D sufficiency,” Wolf concludes. “Our findings suggest that promoting adequate vitamin D status in young, otherwise healthy adults may improve nitric oxide availability and blood vessel function, and thereby serve as a prophylactic to reduce risk of future development of hypertension or cardiovascular disease.”

Researchers presented their findings at the Experimental Biology (EB) 2021 meeting.