Augusta University vitamin D trial offers hope

Clinical study could benefit overweight African-Americans.

Vitamin D wasn’t even on her radar before Celestine Williams was approached in 2011 to do a clinical study at Augusta University.

“I didn’t know anything about it,” she said. But Williams and dozens of others are providing more evidence that people like her who were vitamin D deficient could see some beneficial effects from taking higher doses of the supplement.

Williams took part in one of the first randomized control trials on black people who were overweight or obese that looked at whether giving them vitamin D could have an impact on their blood vessels.

Black people are at higher risk of being vitamin D deficient because darker skin has more difficulties converting sunlight into vitamin D, said corresponding author Yanbin Dong. People who are overweight and obese also are at higher risk because fat cells tend to grab vitamin D and don’t release it back into circulation, he said.

Vitamin D deficiency has been associated with higher rates of cardiovascular disease, stroke and death from heart disease, according to the study, which was published last month in the journal PLOS One. Cardiovascular disease is the leading cause of death among African-Americans, so there is a critical need to find early indicators for prevention and potential intervention, according to the study.

In the study, 70 overweight or obese black subjects were randomly assigned to receive either a placebo or daily supplements of vitamin D in various strengths of 600 International Units, 2,000 or 4,000 units, over 16 weeks. The researchers then used measures to look at arterial stiffness, an important indicator and risk factor for cardiovascular disease.

Those in the placebo group saw an increase in blood vessel stiffness, while those in the 2,000 and 4,000 groups saw the biggest drop in arterial stiffness, with the highest in drop in one measure among the 4,000 dose group.

Dong cautions that there is a lot of controversy surrounding vitamin D already. Some people believe it is a “magic bullet,” while others don’t think much of it or don’t know much about it. The supplement “will be controversial for years” until some large-scale clinical trials are concluded.

The Augusta University team is associated with an ongoing vitamin D and Omega-3 supplement clinical trial run out of Brigham and Women’s Hospital in Boston, where the supplements are being studied in relation to a number of diseases, such as heart disease and cancer. The trial will conclude around 2019, Dong said.

Vitamin D clinical trial results have been mixed in the past in part because some trials gave the supplement to people who had sufficient vitamin D levels at the start of the trial, proving the old adage that “you can’t make healthy people super-healthy by giving them a supplement,” Dong said. “If you don’t have a problem, you don’t need vitamin D.”

After she participated in the study, Williams went to her physician and got a prescription for higher-dose vitamin D and “I got my vitamin D levels up,” she said, to the point where she is no longer taking a supplement unless she needs one.