RESUMO
Vitamin D as a part of the endocrine system is an important component in the interaction between the kidney, bone, parathyroid hormone, and the intestine, which maintains extracellular calcium level within normal limits, in order to keep the vital physiologic process and skeletal integrity. Vitamin D is also associated with hypertension, muscular function, immunity, and ability to encounter infection, autoimmune disease, and cancer. The role of vitamin D in immunity is a feedback reaction of paracrine to eliminate inflammation or to influence CD4 T-cell differentiation and or to increase the function of T suppressor cell or combination between both. The active form of vitamin D produces and maintains self immunologic tolerance, some studies show that 1,25(OH)2D inhibits induction of disease in autoimmune encephalomyelitis, thyroiditis, type-1 diabetes mellitus, inflammatory bowel disease (IBD), systemic lupus erythematosus, and collagen-induced arthritis and Lyme arthritis.