Principal Results of the VITamin D and OmegA-3 TriaL (VITAL) and Updated Meta-analyses

Researchers randomly assigned 25,871 generally healthy adults to take vitamin D, fish oil, both, or look-alike pills. The participants were men aged 50 or older and women aged 55 or older, and they were followed for about 5 years. Vitamin D did not lower the overall chance of developing cancer or major heart problems. Fish oil did not lower the study’s overall heart-disease outcome, although it did reduce heart attacks, especially among people who ate little fish. Combining these results with earlier studies also did not show a clear overall prevention benefit.

What this means for you: For generally healthy adults, this study does not support buying vitamin D or fish oil specifically to prevent cancer or heart disease. These supplements may still have other uses, but this trial found little broad protection.