title: The effect of vitamin D on airway reactivity and inflammation in asthmatic children: A double-blind placebo-controlled trial.
abstract: BACKGROUND
  Cross-sectional studies have reported an association of vitamin D deficiency with increased asthma prevalence and severity, and with allergies. The effect of vitamin D as sole therapy on airway hyper-reactivity (AHR) and airway inflammation has not been reported.
  
  
  OBJECTIVE
  To evaluate the effect of vitamin D therapy on AHR as assessed by methacholine concentration, causing a 20% reduction in FEV1 (PC20 -FEV1 ) and fractional exhaled nitric oxide (FeNO), systemic markers of allergy and inflammation, and exhaled breath condensate cytokines.
  
  
  METHODS
  Children aged 6-18 years with a clinical diagnosis of mild asthma currently not receiving anti-inflammatory therapy and with low vitamin D levels were included in this randomized, double-blind, placebo-controlled study assessing the effect of 6 weeks of treatment with oral vitamin D 14,000 units once weekly or placebo.
  
  
  RESULTS
  Of the 39 patients included, 20 received vitamin D treatment and 19 received a placebo. Vitamin D replacement resulted in a significant increase in vitamin levels, which remained unchanged in the placebo group (P < 0.0001). There was no change in IgE, eosinophil count, high sensitivity C-reactive protein, FeNO levels or PC20 -FEV1 following treatment. Similar values of exhaled breath condensate cytokines (IL4, IL5, IL10, IL17, and γ interferon) were observed in both groups.
  
  
  CONCLUSIONS
  In our small group of children with mild asthma, no difference could be demonstrated between the effect of vitamin D and placebo, despite significant increases in vitamin D blood levels. Larger interventional studies are needed to fully explore the possible effect of vitamin D in asthma.
authors.affiliation: Pediatric Pulmonology Unit, Meyer Children's Hospital, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Ronen
authors.initials: R
authors.lastname: Bar Yoseph
authors.affiliation: Pediatric Pulmonology Unit, Meyer Children's Hospital, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Galit
authors.initials: G
authors.lastname: Livnat
authors.affiliation: Pediatric Pulmonology Unit, Meyer Children's Hospital, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Zeev
authors.initials: Z
authors.lastname: Schnapp
authors.affiliation: Pediatric Pulmonology Unit, Meyer Children's Hospital, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Fahed
authors.initials: F
authors.lastname: Hakim
authors.affiliation: Department of Pediatrics, Western Galilee Hospital, Nahariya, Israel.|Faculty of Medicine, Galilee Bar-Ilan University, Safed, Israel.
authors.forename: Husein
authors.initials: H
authors.lastname: Dabbah
authors.affiliation: Department of Pediatrics, Soroka University Medical Center, Beer Sheba, Israel.
authors.forename: Aviv
authors.initials: A
authors.lastname: Goldbart
authors.affiliation: Pediatric Pulmonology Unit, Meyer Children's Hospital, Rambam Health Care Campus, Haifa, Israel.|Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Lea
authors.initials: L
authors.lastname: Bentur
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000188:drug therapy*; D002648:Child; D016207:Cytokines / Q000378:metabolism; D004311:Double-Blind Method; D045853:Exhalation; D005260:Female; D006801:Humans; D007249:Inflammation / Q000188:drug therapy*; D008297:Male; D012129:Respiratory Function Tests; D014807:Vitamin D / Q000008:administration & dosage* / Q000097:blood; D014815:Vitamins / Q000008:administration & dosage* / Q000097:blood
chemical_list: D016207:Cytokines; D014815:Vitamins; D014807:Vitamin D
keywords: airway hyper-reactivity; exhaled breath condensate; fractional exhaled nitric oxide; vitamin D