title: Vitamin D status is associated with relapse rate in pediatric-onset multiple sclerosis.
abstract: OBJECTIVE
  We sought to determine if vitamin D status, a risk factor for multiple sclerosis, is associated with the rate of subsequent clinical relapses in pediatric-onset multiple sclerosis.
  
  
  METHODS
  This is a retrospective study of patients with pediatric-onset multiple sclerosis or clinically isolated syndrome who were consecutively recruited into a prospective cohort at their clinical visit at the pediatric multiple sclerosis center of University of California, San Francisco or State University of New York at Stony Brook. Of 171 eligible patients, 134 (78%) with multiple sclerosis/clinically isolated syndrome were included in the cohort; a further 24 were excluded from this analysis due to lack of available serum (n = 7) or lack of follow-up (n = 17). Serum 25-hydroxyvitamin D(3) levels were measured and were adjusted to reflect a deseasonalized value. The adjusted serum 25-hydroxyvitamin D(3) level was the primary predictor in a multivariate negative binomial regression model in which the main outcome measure was the number of subsequent relapses.
  
  
  RESULTS
  Among the 110 subjects, the mean unadjusted 25-hydroxyvitamin D(3) level was 22 +/- 9 ng/ml. After adjustment for age, gender, race, ethnicity, disease duration, disease-modifying therapy, and length of follow-up, every 10 ng/ml increase in the adjusted 25-hydroxyvitamin D(3) level was associated with a 34% decrease in the rate of subsequent relapses (incidence rate ratio, 0.66; 95% confidence interval, 0.46-0.95; p = 0.024).
  
  
  CONCLUSIONS
  Lower serum 25-hydroxyvitamin D(3) levels are associated with a substantially increased subsequent relapse rate in pediatric-onset multiple sclerosis or clinically isolated syndrome, providing rationale for a randomized controlled trial of vitamin D supplementation.
authors.affiliation: MS Center, Department of Neurology, University of California, San Francisco, San Francisco, CA 94117, USA. ellen.mowry@ucsf.edu
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Mowry
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Krupp
authors.forename: Maria
authors.initials: M
authors.lastname: Milazzo
authors.forename: Dorothee
authors.initials: D
authors.lastname: Chabas
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Strober
authors.forename: Anita L
authors.initials: AL
authors.lastname: Belman
authors.forename: Jamie C
authors.initials: JC
authors.lastname: McDonald
authors.forename: Jorge R
authors.initials: JR
authors.lastname: Oksenberg
authors.forename: Peter
authors.initials: P
authors.lastname: Bacchetti
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Waubant
mesh_terms: D000293:Adolescent; D002112:Calcifediol / Q000097:blood*; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000097:blood*; D010372:Pediatrics; D012008:Recurrence; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D002112:Calcifediol