A national clinical trial that included researchers and patients from Maine has found that vitamin D supplements do not prevent type 2 diabetes. Vitamin D is widely touted as a supplement that can prevent diseases ranging from cancer to Alzheimer’s, but this latest study provides evidence to the contrary.
The blind, randomized trial included nearly 2,500 people across the U.S. at high risk for diabetes, including more than 100 in Maine. Participants were either given 4,000 units of vitamin D per day or a placebo for about two and a half years.
Dr. Irwin Brodsky of the Maine Medical Center Research Institute, one of the study sites, says the research is important given what he calls the “excess enthusiasm” for using vitamin D to treat or prevent a range of ailments with little evidence.
“It’s resulted in heavy costs for the country. There’s a lot of vitamin D testing going on, a lot of vitamin D sales over the counter. And I think it was time to prove whether it did some of the things that people had said it would, and I think we’ve shown it really didn’t,” he says.
Further, Brodsky says, there’s wide variation among what physicians consider normal levels of vitamin D. He says clinicians should adhere to definitions outlined by the National Academy of Sciences.
Tufts Medical Center in Boston led the study. The results are published in the New England Journal of Medicine.
Originally published June 7, 2019 at 3:46 p.m. ET.