title: Role of vitamin D in the onset, progression, and severity of multiple sclerosis.
abstract: OBJECTIVE
  To review and assess the role of vitamin D in the onset, progression, and relapse of multiple sclerosis (MS), based on evidence acquired from the analysis of preclinical, observational, and interventional studies.
  
  
  METHODS
  All English language literature in MEDLINE (January 1969 through April 2012) was searched for observational and interventional studies on the dosage effect of vitamin D on the onset, progression, and relapse rate of MS. The medical subject heading (MeSH) terms used in the search included Vitamin D and Multiple Sclerosis. Additional publications and abstracts were identified from review articles and from the references cited in the previously found articles. In addition to the experimental studies, only those human studies that specified the population size, doses of vitamin D used, and the resulting effect on MS were considered.
  
  
  RESULTS
  Vitamin D deficiency is very common among MS patients. Multiple preclinical studies have shown that vitamin D is a potent regulator of inflammation in MS. Most observational studies support an association between high vitamin D levels and a reduced risk of developing MS. However, conflicting results have been reported by observational studies on the correlation between vitamin D and MS severity and by interventional studies using vitamin D as a therapeutic agent for MS.
  
  
  CONCLUSIONS
  Vitamin D deficiency in MS patients should be avoided. In addition, the risk of developing MS might be reduced by maintaining optimal vitamin D levels in the healthy population. Larger randomized interventional trials are needed to clarify the therapeutic effect of vitamin D in MS.
authors.affiliation: Division of Endocrinology, University of Florida College of Medicine-Jacksonville, Jacksonville, FL 32209, USA.
authors.forename: Sandra
authors.initials: S
authors.lastname: Mesliniene
authors.forename: Laurie
authors.initials: L
authors.lastname: Ramrattan
authors.forename: Stanley
authors.initials: S
authors.lastname: Giddings
authors.forename: Mae
authors.initials: M
authors.lastname: Sheikh-Ali
mesh_terms: D019587:Dietary Supplements; D018450:Disease Progression; D006801:Humans; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology* / Q000503:physiopathology; D012720:Severity of Illness Index; D014807:Vitamin D / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000150:complications* / Q000188:drug therapy; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D014815:Vitamins; D014807:Vitamin D