Vitamin D Supplements Could Lower Risk of Heart Disease for Individuals With Darker Skin

A study presented at the American Physiological Society annual meeting found links between skin pigmentation, vitamin D, and indicators of cardiovascular health, suggesting vitamin D deficiency could contribute to the 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,” said S. Tony Wolf, PhD, a postdoctoral fellow at the Pennsylvania State University and the study's lead author, in a press 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.”

Melanin, which is more concentrated in darker skin, inhibits the process of vitamin D production in the presence of sunlight. Consequentially, darkly pigmented people may make less vitamin D, potentially leading to deficiency, according to the study.

The investigators measured skin pigmentation, vitamin D, and the activity of nitric oxide in the small blood vessels beneath the skin in 18 heathy adults of varying skin tones. Nitric oxide is important for blood vessel function, and low levels of nitric oxide availability are thought to predispose an individual to the development of hypertension or cardiovascular disease, according to the researchers. Previous studies have suggested vitamin D helps to promote nitric oxide availability.

Participants with darker skin were found to have lower levels of vitamin D and lower nitric oxide availability. Additionally, the researchers found that lower levels of vitamin D were related to reduced nitric oxide-mediated blood vessel function. These results align with the results of a separate study from the same research group, which found that vitamin D supplementation improved blood vitamin D levels and nitric oxide-mediated blood vessel function in otherwise healthy, young African American adults.

“Vitamin D supplementation is a simple and safe strategy to ensure vitamin D sufficiency," Wolf said in the release. "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.”

REFERENCE

Taking vitamin D could lower heart disease risk for people with dark skin [news release]. EurekAlert; April 26, 2021. Accessed May 4, 2021. https://www.eurekalert.org/pub_releases/2021-04/eb-tvd041621.php