Vitamin D3 in Systemic Lupus Erythematosus

Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by the production of autoantibodies with subsequent immune complex deposition and tissue inflammation. The role of interferon (IFN) alpha in the development of SLE has been repeatedly documented. Vitamin D deficiency is common among lupus patients. Vitamin D is recognized as a regulator of immune response. This study will explore the impact of vitamin D3 supplementation on IFN alpha expression in SLE patients. The study will last approximately 12 weeks and consist of three treatment groups: 1.) Participants will receive vitamin D3 2000 IU daily 2.) Participants will receive vitamin D3 4000 IU daily 3.) Participants will receive a vitamin D3 placebo daily. There will be four study visits for each participant. Visits will occur at screening, study entry, and Weeks 6 and 12. Physical examination, vital signs, and blood and urine tests will occur at all visits. For females of childbearing potential, a pregnancy test will be performed at screening and Week 6.