title: Mounting evidence for vitamin D as an environmental factor affecting autoimmune disease prevalence.
abstract: Low vitamin D status has been implicated in the etiology of autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, insulin-dependent diabetes mellitus, and inflammatory bowel disease. The optimal level of vitamin D intake required to support optimal immune function is not known but is likely to be at least that required for healthy bones. Experimentally, vitamin D deficiency results in the increased incidence of autoimmune disease. Mechanistically, the data point to a role for vitamin D in the development of self-tolerance. The vitamin D hormone (1,25-dihydroxy vitamin D(3)) regulates T helper cell (Th1) and dendritic cell function while inducing regulatory T-cell function. The net result is a decrease in the Th1-driven autoimmune response and decreased severity of symptoms. This review discusses the accumulating evidence pointing to a link between vitamin D and autoimmunity. Increased vitamin D intakes might decrease the incidence and severity of autoimmune diseases and the rate of bone fracture.
authors.affiliation: Department of Nutritional Sciences, Pennsylvania State University, University Park, PA 16802, USA. mxc69@psu.edu
authors.forename: Margherita T
authors.initials: MT
authors.lastname: Cantorna
authors.forename: Brett D
authors.initials: BD
authors.lastname: Mahon
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology; D004032:Diet; D006801:Humans; D018448:Models, Immunological; D015995:Prevalence; D018167:Receptors, Calcitriol / Q000378:metabolism; D017634:Self Tolerance / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014807:Vitamin D / Q000502:physiology*; D014808:Vitamin D Deficiency / Q000276:immunology*
chemical_list: D018167:Receptors, Calcitriol; D014807:Vitamin D