Taking a daily vitamin D supplement does not prevent type 2 diabetes in adults at high risk, according to results from the Vitamin D and Type 2 Diabetes (D2d) study, funded by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health (NIH). 

The study enrolled 2,423 adults with a range of physical characteristics, including sex, age, and body mass index, as well as racial and ethnic diversity, which helps ensure that the findings could be widely applicable to people at high risk for developing type 2 diabetes. The study was conducted at 22 sites across the United States.

Subjects were randomly assigned to either take 4,000 IU of the D3 (cholecalciferol) form of vitamin D or a placebo pill daily. All study participants had their baseline vitamin D levels measured. The subjects were screened every 3 to 6 months for an average of 2.5 years to determine if diabetes had developed. Researchers then compared the number of people in each of the two study groups that had progressed to type 2 diabetes.

At the end of the study, 293 out of 1211 participants (24.2%) in the vitamin D group developed diabetes compared to 323 out of 1212 (26.7%) in the placebo group, although this difference was not statistically significant. The study was designed to detect a risk reduction of 25% or more.

These findings presented at the ongoing 79th Scientific Sessions of the American Diabetes Association (ADA) in San Francisco and simultaneously published in the New England Journal of Medicine.

(Source: NIH, June 7, 2019)

Dr KK Aggarwal

Padma Shri Awardee

President Elect Confederation of Medical Associations in Asia and Oceania   (CMAAO)

Group Editor-in-Chief IJCP Publications

President Heart Care Foundation of India

Past National President IMA