Vitamin D and systemic lupus erythematosus: continued evolution.

Vitamin D is a steroid hormone that has well-established roles in calcium and bone metabolism. Vitamin D has more recently become recognized for its role in the immune response and its potential immunomodulatory effects in autoimmune diseases, including systemic lupus erythematosus (SLE). This review provides a summary of the recent literature regarding vitamin D and SLE, as well as current recommendations for vitamin D supplementation in patients with SLE.