Study of Vitamin D and Omega-3 Supplementation for Preventing Diabetes

Summary

The VITamin D and OmegA-3 TriaL (VITAL; NCT 01169259) is an ongoing randomized clinical trial in 25,875 U.S. men and women investigating whether taking daily dietary supplements of vitamin D3 (2000 IU) or omega-3 fatty acids (Omacor® fish oil, 1 gram) reduces the risk of developing cancer, heart disease, and stroke in people who do not have a prior history of these illnesses. This ancillary study is being conducted among nondiabetic participants in VITAL and will examine whether vitamin D or fish oil prevent type 2 diabetes. Findings from this ancillary study (n=22220 without diabetes at baseline) conducted within the VITAL trial will clarify whether vitamin D and omega-3 fatty acid supplementation reduces risk of type 2 diabetes and thus will inform public health and clinical guidelines for diabetes prevention.

Timeline

Start

2011-11

Primary completion

2024-05-30

Completion

2024-05-30

Publications

• Tobias DK, Pradhan AD, Duran EK, Li C, Song Y, Buring JE, Cook NR, Mora S, Manson JE. Vitamin D supplementation vs. placebo and incident type 2 diabetes in an ancillary study of the randomized Vitamin D and Omega-3 Trial. Nat Commun. 2025 Apr 8;16(1):3332. doi: 10.1038/s41467-025-58721-6.

Drugs

Indications