Vitamin D Supplements Cut Risk for Autoimmune Disease in VITAL

This transcript has been edited for clarity.

Hello. This is Dr JoAnn Manson, professor of medicine at Harvard Medical School and Brigham and Women's Hospital.

I'd like to talk about recent promising research from the vitamin D and omega-3 in the prevention of autoimmune diseases (VITAL) trial, recently published in The BMJ . We tested vitamin D 2000 IUs daily and marine omega-3 fatty acids 1 g daily in a study population of more than 25,000 US adults who were older than age 50 years and were treated for more than 5 years. The main goals were the prevention of cancer and cardiovascular disease, but we were also interested in other outcomes, including autoimmune diseases. We collaborated with colleagues in rheumatology (Dr Jill Hahn and Dr Karen Costabader) to look at a composite of autoimmune disorders, as well as individual conditions such as rheumatoid arthritis, polymyalgia rheumatica, psoriasis, autoimmune thyroid disease, and others, confirmed by medical records.

We were interested in these endpoints because it's been shown in laboratory and clinical studies that vitamin D does regulate the genes that are involved with immunity and immune modulation. Both vitamin D and omega-3s have been shown to reduce or tamp down inflammation.