In addition to its role in calcium homeostasis, it is believed that the active form of vitamin D has immunomodulatory effects, suppressing or activating the immune system. Recent studies have linked vitamin D deficiency or insufficiency with multiple autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes Mellitus and multiple sclerosis. Thus, the present review describes vitamin D metabolism and its functions, emphasizing its action on the immune system as well as its participation in systemic lupus erythematosus. All evidence focuses on the relationship between low vitamin D levels and the clinical manifestation of systemic lupus erythematosus, but it is not yet clear whether supplementation or reestablishment of normal levels can influence disease activity. Thus, more studies are needed to assess the possible therapeutic benefits of vitamin D supplementation on systemic lupus erythematosus.
Immune system; Systemic lupus erythematosus; Vitamin D
