Vitamin D in high doses has been shown to reduce arterial stiffness, an independent predictor of cardiovascular-related disease. Previously recognized for its role in bone health, researchers at the Medical College of Georgia tested the effects of varying doses of vitamin D on 70 African-Americans aged 13-45 who were classified as overweight or obese, but were otherwise relatively healthy.
This segment of the population was singled out for the study because overweight African-Americans are believed to be at a greater risk of vitamin D deficiency. Geneticist and cardiologist Dr. Yanbin Dong said this is due to the fact that fat tends to trap vitamin D and keep it from providing benefit and darker skin absorbs less sunlight, which is one of the main providers of vitamin D.
Dong and his team’s work was detailed recently in the journal PLoS ONE. Volunteers that took 4,000 international units daily, considered the highest, safe upper dose by the Institute of Medicine, saw a reduction of arterial stiffness by 10.4 percent in just four months. At the same time, those that took 2,000 IUs saw a decrease of 2 percent.
The current recommendation for vitamin D consumption is 600 IUs, but that amount was not enough to affect a positive change in the state of the volunteers’ arteries. In fact, the ones that received that dosage had a slight increase of 0.1 percent in stiffness. The control group that received a placebo had an increase in arterial stiffness of 2.3 percent.
Researchers used pulse wave velocity to assess arterial stiffness. "When your arteries are more stiff, you have higher pulse wave velocity, which increases your risk of cardiometabolic disease in the future," said Dr. Anas Raed.
Heart disease is the leading cause of death in the United States and arterial stiffness and vitamin D deficiency are thought to be possible contributors. The Centers for Disease Control and Prevention says blacks have higher rates of cardiovascular disease and death, and heart disease tends to appear earlier in life than in whites.
While the reason for vitamin D’s improvement in arterial stiffness is not completely understood, Dong and Raed believe this information gives them the impetus to pursue a larger scale study for longer periods of time.