Vitamin D may help make arteries healthier.

According topreliminary researchfrom the Medical College of Georgia at Augusta University, high doses of vitamin D seem to keep arteries more flexible and pliable, potentially warding off future heart disease, heart attacks and strokes.

A small-scale clinical trial of a group of 70 young black men and women were tested to see how vitamin D helps with flexibility in arteries. Results showed that arterial stiffness was reduced in just four months while taking vitamin D supplements.

“The vitamin D receptor is expressed everywhere in your body, in almost every single type of cell,” said Dr.Yanbin Dong, senior researcher and professor at the Medical College of Georgia at Augusta University. “That’s why people think vitamin D might have something more to offer.”

Dong and his colleagues recruited a group of overweight or obese black Americans who were deficient in vitamin D. While human skin naturally synthesizes vitamin D when exposed to bright sunshine, darker skin absorbs less sunlight, making black people more susceptible to vitamin deficiency, the researchers said, as reported in U.S. News.

In addition, body fat tends to capture and hold vitamin D, also contributing to deficiency.

The study participants were placed into four groups. Three groups took oral doses of vitamin D amounting to 600 international units (IU), 2,000 IU or 4,000 IU daily. The fourth group took placebos.

The National Academy of Medicine currently recommends that people get 600 IU of vitamin D daily, Dong said. The researchers chose 2,000 IU because they suspected that might be the best dose, and 4,000 IU because that's the highest level before people start experiencing toxic effects.

Those in the study who took 4,000 IU daily -- more than six times the currently recommended amount -- experienced a 10.4% reduction in arterial stiffness within four months, the findings showed.

Those who took 2,000 IU a day experienced a 2% decrease in arterial stiffness during the same time frame. People who took the currently recommended dose of 600 IU had a slight increase in arterial stiffness -- about 0.1%. Those who took the placebos had a 2.3% increase, according to the report.

No toxic effects were observed among people who took the larger doses of the vitamin, Dong said.

A previous study on Vitamin D and arterial stiffness was published in October in the Journal of the American Heart Association (JAHA.)