title: Vitamin D in systemic and organ-specific autoimmune diseases.
abstract: Lately, vitamin D has been linked with metabolic and immunological processes, which established its role as an essential component of human health preservation. Vitamin D has been defined as natural immune modulators, and upon activation of its receptors (VDRs), it regulates calcium metabolism, cellular growth, proliferation and apoptosis, and other immunological functions. Epidemiological data underline a strong correlation between poor vitamin D status and higher risk for chronic inflammatory illnesses of various etiologies, including autoimmune diseases. Epidemiological, genetic, and basic studies indicated a potential role of vitamin D in the pathogenesis of certain systemic and organ-specific autoimmune diseases. These studies demonstrate correlation between low vitamin D and prevalence of diseases. In addition, VDRs' polymorphisms observed in some of these autoimmune diseases may further support a plausible pathogenic link. Notably, for some autoimmune disease, no correlation with vitamin D levels could be confirmed. Thus, in the current review we present the body of evidence regarding the plausible roles of vitamin D and VDR's polymorphism in the pathogenesis of autoimmunity. We summarize the data regarding systemic (i.e., systemic lupus erythematosus, rheumatoid arthritis, etc.) and organ-specific (i.e., multiple sclerosis, diabetes mellitus, primary biliary cirrhosis, etc.) autoimmune diseases, in which low level of vitamin D was found comparing to healthy subjects. In addition, we discuss the correlations between vitamin D levels and clinical manifestations and/or activity of diseases. In this context, we address the rational for vitamin D supplementation in patients suffering from autoimmune diseases. Further studies addressing the mechanisms by which vitamin D affects autoimmunity and the proper supplementation required are needed.
authors.affiliation: The Zabludowics Center for Autoimmune Diseases, Chaim Sheba Medical Center, Tel Hashomer, 52621, Israel.
authors.forename: Nancy
authors.initials: N
authors.lastname: Agmon-Levin
authors.forename: Emanuel
authors.initials: E
authors.lastname: Theodor
authors.forename: Ramit Maoz
authors.initials: RM
authors.lastname: Segal
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Shoenfeld
mesh_terms: D000818:Animals; D017209:Apoptosis; D001327:Autoimmune Diseases / Q000178:diet therapy / Q000453:epidemiology* / Q000276:immunology*; D002118:Calcium / Q000378:metabolism; D048708:Cell Growth Processes; D019587:Dietary Supplements; D018450:Disease Progression; D020022:Genetic Predisposition to Disease; D006801:Humans; D056747:Immunomodulation; D009928:Organ Specificity; D011110:Polymorphism, Genetic; D018167:Receptors, Calcitriol / Q000235:genetics; D014807:Vitamin D / Q000378:metabolism*; D014808:Vitamin D Deficiency / Q000453:epidemiology*
chemical_list: D018167:Receptors, Calcitriol; D014807:Vitamin D; D002118:Calcium