Vitamin D reduce arterial stiffness

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WASHINGTON: High-doses of vitamin D are effective in reducing arterial stiffness, finds a study. Researchers said that in just four months, high-doses of vitamin D reduce arterial stiffness in young, overweight/obese, vitamin-deficient, but otherwise still healthy African-Americans.
Rigid artery walls are an independent predictor of cardiovascular- related disease and death and vitamin D deficiency appears to be a contributor, says Dr. Yanbin Dong, geneticist and cardiologist at the Georgia Prevention Institute at the Medical College of Georgia at Augusta University.
So researchers looked at baseline and again 16 weeks later in 70 African-Americans ages 13-45 – all of whom had some degree of arterial stiffness – taking varying doses of the vitamin best known for its role in bone health.
In what appears to be the first randomized trial of its kind, they found that arterial stiffness was improved by vitamin D supplementation in a dose-response manner in this population.
Overweight/obese blacks are at increased risk for vitamin D deficiency because darker skin absorbs less sunlight – the skin makes vitamin D in response to sun exposure – and fat tends to sequester vitamin D for no apparent purpose, says Dong, the study’s corresponding author.
Participants taking 4,000 international units – more than six times the daily 600 IUs the Institute of Medicine currently recommends for most adults and children – received the most benefit, says Dr. Anas Raed, research resident in the MCG Department of Medicine and the study’s first author. The dose, now considered the highest, safe upper dose of the vitamin by the Institute of Medicine, reduced arterial stiffness the most and the fastest: 10.4 percent in four months. “It significantly and rapidly reduced stiffness,” Raed says.
Two thousand IUs decreased stiffness by 2 percent in that timeframe. At 600 IUs, arterial stiffness actually increased slightly – .1 percent – and the placebo group experienced a 2.3 percent increase in arterial stiffness over the timeframe.
They used the non-invasive, gold standard pulse wave velocity to assess arterial stiffness. Reported measures were from the carotid artery in the neck to the femoral artery, a major blood vessel, which supplies the lower body with blood. The American Heart Association considers this the primary outcome measurement of arterial stiffness. When the heart beats, it generates a waveform, and with a healthy heart and vasculature there are fewer and smaller waves. The test essentially measures the speed at which the blood is moving, and in this case, fast is not good, Raed says.
“When your arteries are more stiff, you have higher pulse wave velocity, which increases your risk of cardiometabolic disease in the future,” says Raed. The findings have been published in the journal PLOS ONE.