Many supplements, particularly those with antioxidant or anti-inflammatory activity, have been investigated for their ability to reduce the severity or incidence of autoimmune disease. To date, some of the more promising evidence is for vitamin D and fish oil, which were linked to reduced incidence of autoimmunity in a large randomized controlled trial.[1] Further research is needed to better understand the way that supplements may affect the incidence or severity of autoimmunity in different people.