Vitamin D Supplements Don’t Prevent Type 2 Diabetes: Study

Vitamin supplements don’t appear to prevent type 2 diabetes in those at highest risk for the disease, a new study finds.

Some studies have suggested that low vitamin D levels might increase the odds of developing diabetes and that boosting levels could prevent it, but these findings throw cold water on these assumptions.

In this study funded by the U.S. National Institutes of Health (NIH), more than 2,400 people aged 30 and older across the United States were involved. Researchers randomly assigned half of them to take 4,000 units a day of vitamin D and the other half to take a placebo.

After nearly three years, 24.2% of those taking vitamin D developed diabetes, as did 26.7% of those taking the placebo. This difference isn’t statistically significant, researchers said.

“In addition to the study’s size, one of its major strengths is the diversity of its participants, which enabled us to examine the effect of vitamin D across a large variety of people,” lead author Dr. Anastassios Pittas said in an NIH news release. “When the study ended, we found no meaningful difference between the two groups regardless of age, sex, race or ethnicity.”

Pittas is a professor and co-director of the Diabetes and Lipid Center at Tufts University Medical Center in Boston.

The report was published June 7 in the New England Journal of Medicine to coincide with its presentation at a meeting of the American Diabetes Association, in San Francisco.

More information

The American Diabetes Association offers more details about type 2 diabetes.