Vitamin D and marine omega-3 fatty acids positively affect autoimmune disease incidence.

Autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, and psoriasis are an inflammatory autoimmune response to body's own cells, organs and tissues. Autoimmune conditions are the third leading cause of morbidity in the developed countries and a main cause of death among women. Autoimmune diseases are chronic conditions and have significant societal and economic burden due to a lack of effective treatments.

Vitamin D is known to regulate genes involved in inflammation and immunity and has been often associated with lowering the risk of some autoimmune diseases. Dietary marine-derived long-chain omega-3 fatty acids reduce systemic inflammation and improve symptoms in few autoimmune diseases. But there is not enough evidence proving that omega-3 fatty acids lower the risk of developing autoimmune disease.

A trial done by Hahn et al. on older adults in the U.S. demonstrated that the supplementation of vitamin D and omega-3 fatty acid for 5 years decreases autoimmune disease incidence compared with no supplementation. Both of these are well tolerated, non-toxic supplements, so the result of this study has high clinical importance. Especially as there is a lack of other effective treatments to reduce the incidence of autoimmune diseases.

More than twenty-five thousand participants were enrolled and participated for a median of 5.3 years. The mean age of participants was 67.1 years. In this large trial in a cohort of diverse older Americans, the supplementation with vitamin D was at a dose of 2000 IU/day for five years, alone or together with 1 g/day of omega-3 fatty acids. 

The researchers tested three different groups receiving supplementation: vitamin D + omega-3 fatty acids; vitamin D + placebo and placebo + omega 3 fatty acids. All groups had lower cumulative incidence of confirmed autoimmune disease duringf 5 year trial than the group receiving placebo of both supplements. This publication also suggested that people with lower body mass index seem to benefit more from vitamin D treatment. The positive effect of omega-3fatty acids on autoimmune disease prevention was higher between participants with autoimmune disease family history compared with those with no family history.

The results of the study confirmed that vitamin D supplementation for five years, with or without omega-3, decreased autoimmune disease by 22%, while omega-3 fatty acid supplementation with or without vitamin D reduced the autoimmune disease rate by 15%. This study gives hope for a safe and well-tolerated treatment for those at risk of autoimmune disease or those who already have the disease.

Source: link

‍