Vitamin D and Fish Oil for Autoimmune Disease, Inflammation and Knee Pain

The VITamin D and OmegA-3 TriaL (VITAL; NCT 01169259) is a randomized clinical trial in 25,871 U.S. men and women investigating whether taking daily dietary supplements of vitamin D3 (2000 IU) or omega-3 fatty acids (Omacor® fish oil, 1 gram) reduces the risk of developing cancer, heart disease, and stroke in people who do not have a prior history of these illnesses. This ancillary study is being conducted among VITAL participants and will examine whether vitamin D or fish oil have effects upon A) autoimmune disease incidence, B) biomarkers of systemic inflammation, and C) chronic knee pain. Blood samples at baseline and in follow-up will be collected in a randomly selected subcohort of 1500 individuals and analyzed for changes in biomarkers of systemic inflammation: C-reactive protein, interleukin-6, and tumor necrosis factor-receptor 2. Approximately 1300 individuals with chronic, frequent knee pain will be followed with annual questionnaires to evaluate the effects of the supplements on chronic knee pain.