title: Current treatment recommendations for correcting vitamin D deficiency in pediatric patients with cystic fibrosis are inadequate.
abstract: OBJECTIVE
  To determine the prevalence of vitamin D deficiency (25-hydroxy vitamin D [25-OHD] levels in plasma <30 ng/mL) in pediatric patients with cystic fibrosis (CF), elucidate contributing factors for vitamin D deficiency, and determine the efficacy of ergocalciferol repletion strategies.
  
  
  METHODS
  Retrospective chart review of 262 pediatric patients from January 2003 to December 2006 with linear and logistic regression analyses.
  
  
  RESULTS
  Vitamin D deficiency prevalence declined in the years studied from 86.5% to 46.2%. Patients >12 years old were more likely to have deficiency than patients <5 years old (odds ratio [OR], 3.44; 95% CI, 1.73-6.84). Levels obtained in spring and summer were less likely to be deficient compared with those obatained in fall (OR, 0.24; 95% CI, 0.10-0.61; and OR, 0.25; 95% CI, 0.11-0.61; respectively). Success of treatment with 50,000 IU of ergocalciferol once, twice, or 3 times weekly was 33%, 26%, and 43%, respectively. Ergocalciferol, when compared with no treatment, did not significantly increase the proportion of patients with follow-up levels > or =30 ng/mL (chi(2)P value = .80, .34, and .22, respectively).
  
  
  CONCLUSIONS
  The prevalence of vitamin D deficiency is high, but declined with time. Age, forced expiratory volume in 1 second, and season were associated with 25-OHD levels. Despite 33% of patients responding to 50 000 IU of ergocalciferol once a week, this recommendation does not adequately treat most patients with CF who have vitamin D deficiency.
authors.affiliation: Department of Pediatrics, The Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: Deanna
authors.initials: D
authors.lastname: Green
authors.forename: Kathryn
authors.initials: K
authors.lastname: Carson
authors.forename: Amanda
authors.initials: A
authors.lastname: Leonard
authors.forename: J Erin
authors.initials: JE
authors.lastname: Davis
authors.forename: Beryl
authors.initials: B
authors.lastname: Rosenstein
authors.forename: Pamela
authors.initials: P
authors.lastname: Zeitlin
authors.forename: Peter
authors.initials: P
authors.lastname: Mogayzel
mesh_terms: D002648:Child; D003550:Cystic Fibrosis / Q000097:blood / Q000453:epidemiology*; D004872:Ergocalciferols / Q000008:administration & dosage*; D005541:Forced Expiratory Volume; D006801:Humans; D016015:Logistic Models; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D012621:Seasons; D014808:Vitamin D Deficiency / Q000453:epidemiology*; D014815:Vitamins / Q000008:administration & dosage*
chemical_list: D004872:Ergocalciferols; D014815:Vitamins