title: Bronchial Reactivity, Inflammatory and Allergic Parameters, and Vitamin D Levels in Children With Asthma.
abstract: BACKGROUND
  A low serum vitamin D level may represent a marker of other perplexing factors that may lead to increased asthma prevalence and severity. Our aim was to assess the correlation between vitamin D levels and asthma and allergy markers in a subgroup of children with fewer confounding factors.
  
  
  METHODS
  Non-obese children (6-18 y old) with asthma who were not receiving anti-inflammatory treatment were recruited. Subjects underwent spirometry with a methacholine challenge test, and fractional exhaled nitric oxide (FENO), serum vitamin D levels, total immunoglobulin E (IgE) levels, blood eosinophil counts, and high-sensitivity C-reactive protein levels were determined. The primary end point was the correlation between vitamin D level and airway hyper-responsiveness as assessed by a methacholine challenge test. The secondary end point was the correlation between vitamin D level and FENO, systemic inflammatory markers, and allergy.
  
  
  RESULTS
  Seventy-one children with asthma (25 females, 35%; 12.5 ± 3.6 y of age) were included. The median vitamin D level was 23 ng/mL (range of 6-48.5, mean of 23.02 ± 7.74), the median IgE level was 305 IU/mL (range of 4.3-4,240), the median provocational concentration of methacholine that produced a 20% decrease in FEV1 was 1.1 mg/mL (range of 0-13.9), and the median FENO was 26.5 ppb (range of 3.6-285). No correlation was found between vitamin D level and response to the methacholine challenge test, FENO, high-sensitivity C-reactive protein levels, IgE levels, eosinophil counts, and frequency of allergic rhinitis or atopic dermatitis.
  
  
  CONCLUSIONS
  In our group of children with asthma, no correlation was found between the level of vitamin D and the degree of airway reactivity, airway inflammation, and allergy. The cause-and-effect relationship between vitamin D, asthma, and allergy should be further clarified. (ClinicalTrials.gov registration NCT01287455).
authors.affiliation: Department of Pediatrics, Galilee Medical Center, Nahariya, Israel, and the Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel. h_dabbah@rambam.health.gov.il.
authors.forename: Husein
authors.initials: H
authors.lastname: Dabbah
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: Fahed
authors.initials: F
authors.lastname: Hakim
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 / Q000503:physiopathology*; D015415:Biomarkers / Q000032:analysis*; D001985:Bronchial Provocation Tests / Q000379:methods; D016085:Bronchoconstrictor Agents / Q000008:administration & dosage / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis; D002648:Child; D004804:Eosinophils; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000097:blood* / Q000150:complications; D007073:Immunoglobulin E / Q000097:blood; D018836:Inflammation Mediators / Q000097:blood*; D007958:Leukocyte Count; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage / Q000032:analysis; D009569:Nitric Oxide / Q000032:analysis; D066232:Pulmonary Elimination; D013147:Spirometry; D014807:Vitamin D / Q000097:blood*
chemical_list: D015415:Biomarkers; D016085:Bronchoconstrictor Agents; D018836:Inflammation Mediators; D016210:Methacholine Chloride; D014807:Vitamin D; D009569:Nitric Oxide; D007073:Immunoglobulin E; D002097:C-Reactive Protein
keywords: airway hyper-responsiveness; allergic parameters; asthma; fractional exhaled NO; high-sensitivity C-reactive protein; vitamin D