Study of older adults is ‘first direct evidence’ of protection against rheumatoid arthritis, psoriasis, other conditions.In a new study, investigators from Brigham and Women’s Hospital found the people who took vitamin D, or vitamin D and omega-3 fatty acids, had a significantly lower rate of autoimmune diseases such as rheumatoid arthritis, polymyalgia rheumatica, autoimmune thyroid disease, and psoriasis than people who took a placebo. With their findings published Wednesday in BMJ, the team had tested this in the large-scale vitamin D and omega-3 trial (VITAL), a randomized study which followed participants for approximately five years. Investigators found theStudy of older adults is 'first direct evidence' of protection against rheumatoid arthritis, psoriasis, other conditions.In a new study, investigators from Brigham and Women’s Hospital found the people who took vitamin D, or vitamin D and omega-3 fatty acids, had a significantly lower rate of autoimmune di