title: Serum 25-hydroxyvitamin D levels in relation to lung function and exhaled nitric oxide in children.
abstract: OBJECTIVE
  To investigate the relationship of vitamin D status with lung function and fraction of exhaled nitric oxide (FeNO) in a population sample of children.
  
  
  METHODS
  A total of 1315 children aged 5-18 years were evaluated using serum 25-hydroxyvitamin D [25(OH)D] levels, spirometry, a single-breath online FeNO measurement, and questionnaires.
  
  
  RESULTS
  After adjusting for confounders, the mean forced vital capacity was 53.4 mL (SE, 26.5 mL; P = .045), and the mean forced expiratory volume in 1 second was 48.2 mL (SE, 23.6 mL; P = .042) lower for children with insufficient serum 25(OH)D levels (20-29.9 ng/mL) compared with those with sufficient 25(OH)D levels (≥30 ng/mL). The mean difference between children with deficient (<20 ng/mL) and sufficient levels of serum 25(OH)D was 81.9 mL (SE, 26.7 mL; P = .002) for forced vital capacity and 55.2 mL (SE, 23.7 mL; P = .020) for forced expiratory volume in 1 second. There was no significant association between serum 25(OH)D levels and FeNO after adjusting for confounders.
  
  
  CONCLUSIONS
  Our results demonstrate a significant relationship between insufficient serum vitamin D levels and worse lung function in children in the community with a suggested dose-response effect. Our findings also suggest that vitamin D status is not a significant determinant of FeNO in children in the general population.
authors.affiliation: Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan; Community Medicine Research Center, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan. Electronic address: yao@adm.cgmh.org.tw.
authors.forename: Tsung-Chieh
authors.initials: TC
authors.lastname: Yao
authors.affiliation: Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan; Community Medicine Research Center, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan; Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Tu
authors.affiliation: Clinical Informatics and Medical Statistics Research Center, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Su-Wei
authors.initials: SW
authors.lastname: Chang
authors.affiliation: Division of Biostatistics and Bioinformatics, Institutes of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan; Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL; Department of Genome Medicine, Kaohsiung University, Kaohsiung, Taiwan.
authors.forename: Hui-Ju
authors.initials: HJ
authors.lastname: Tsai
authors.affiliation: Department of Laboratory Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Po-Wen
authors.initials: PW
authors.lastname: Gu
authors.affiliation: Department of Laboratory Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Hsian-Chen
authors.initials: HC
authors.lastname: Ning
authors.affiliation: Community Medicine Research Center, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan; Department of Pediatrics, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan.
authors.forename: Man-Chin
authors.initials: MC
authors.lastname: Hua
authors.affiliation: Community Medicine Research Center, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan; Department of Pediatrics, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan.
authors.forename: Sui-Ling
authors.initials: SL
authors.lastname: Liao
authors.affiliation: Community Medicine Research Center, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan; Department of Pediatrics, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan.
authors.forename: Ming-Han
authors.initials: MH
authors.lastname: Tsai
authors.affiliation: Community Medicine Research Center, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan; Department of Pediatrics, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan.
authors.forename: Chih-Yung
authors.initials: CY
authors.lastname: Chiu
authors.affiliation: Community Medicine Research Center, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan; Division of Pediatric Pulmonology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Shen-Hao
authors.initials: SH
authors.lastname: Lai
authors.affiliation: Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan; Community Medicine Research Center, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan.
authors.forename: Kuo-Wei
authors.initials: KW
authors.lastname: Yeh
authors.affiliation: Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan; Community Medicine Research Center, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan. Electronic address: long@adm.cgmh.org.tw.
authors.forename: Jing-Long
authors.initials: JL
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D001944:Breath Tests / Q000379:methods; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D015999:Multivariate Analysis; D009569:Nitric Oxide / Q000032:analysis*; D012044:Regression Analysis; D014797:Vital Capacity; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood / Q000502:physiology; D055815:Young Adult
chemical_list: D014807:Vitamin D; D009569:Nitric Oxide; C104450:25-hydroxyvitamin D