Vitamin D supplementation has been shown to reduce the development of autoimmune disease

Adapted from BMJ 29 Jan 2022

This USA study looked at what happened after 5 years of vitamin D 3, omega 3 fatty acids and placebo to a group of over 12 thousand men and 13 thousand women. The men were at least 50 and the women 55 at the time of the start of the trial.

The groups were randomised to test out different combinations on the incidence of autoimmune diseases including rheumatoid arthritis, polymyalgia rheumatica, autoimmune thyroid disease, and psoriasis.

The results show that the vitamin D supplement group had the only statistically significant finding. This was a 22% reduction in autoimmune disease whether or not they took the vitamin D with omega three fatty acids or a placebo.

Although the doses are probably stated in the main paper, the summary from the BMJ did not contain this information.