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. We were interested in their effects on autoimmune disorders, for which there really are no known primary preventive modalities.
We found that vitamin D significantly reduced the risk for a composite of autoimmune disorders — a 22% significant reduction. When compared with a reference group who received double placebos (placebo for vitamin D and placebo for omega-3s), the reduction in composite autoimmune diseases was greater than 30% with vitamin D. Then accounting for latency, among those who were in the trial for at least 2 years, the reduction was closer to 40%. For the omega-3s, we didn't see a statistically significant reduction, but there was a promising signal — about a 15% reduction.
We're interested in continuing to follow the participants to see if these results strengthen over time. We also would like to do replication studies and look at a younger population. Autoimmune diseases often develop earlier in life, so we will look at younger adults and the effects of these interventions, as well as those who are at high risk for autoimmune disorders because of a strong family history or other risk factors.
Thank you so much for your attention. This is JoAnn Manson.
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Cite this: JoAnn E. Manson. Vitamin D Supplements Cut Risk for Autoimmune Disease in VITAL - Medscape - Feb 16, 2022.