He noted that two recent, similar trials (one in Norway and one in Japan) reported nearly identical, statistically significant risk reductions in the vitamin D group.
There was also some good news in the findings: Vitamin D supplementation “did not lead to significantly more kidney stones, high serum calcium, or low glomerular filtration rate,” Dr. Pittas said.
Although the study findings are disappointing, vitamin D supplementation is still crucial in patients who have low levels, Victor Lawrence Roberts, MD, an endocrinologist in private practice in Orlando, Fla., said in an interview.
“I diagnose at least three or four people a day with vitamin D deficiency,” Dr. Roberts said. “I’ve found if you replace vitamin D in diabetes – get it to 30 ng/ml or better – their diabetes may improve in some cases, although it may be that they’re paying more attention to their health.”
In the big picture, he said, “if people are vitamin D deficient, the vitamin should be replaced no matter what it does to their blood sugar.”
The study was published simultaneously in the New England Journal of Medicine (N Engl J Med. 2019 Jun 7.).
The study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases, the NIH Office of Dietary Supplements, and American Diabetes Association. Dr. Pittas reports grants from the same institutions during the conduct of the study. Many coauthors disclosed relationships with multiple drug companies, but none relevant to the topic under study.
SOURCE: Pittas AG et al.
This article was updated on 6/18/2019.