title: Suboptimal vitamin D status in a population-based study of Asian children: prevalence and relation to allergic diseases and atopy.
abstract: BACKGROUND
  New evidence shows high prevalence of vitamin D deficiency in many countries and some studies suggest a possible link between vitamin D status and allergic diseases. The objectives of this study were to determine the prevalence of suboptimal vitamin D status in a population sample of Asian children and to investigate the relationship of vitamin D status with allergic diseases and atopy.
  
  
  METHODS
  Children aged 5-18 years (N = 1315) in the Prediction of Allergies in Taiwanese CHildren (PATCH) study were evaluated using questionnaires, anthropometric measurements, and serum levels of 25-hydroxyvitamin D [25(OH)D] and total and specific immunoglobulin E (IgE).
  
  
  RESULTS
  The mean concentration of serum 25(OH)D was 20.4 ng/mL (SD: 7.1 ng/mL). Vitamin D deficiency (defined as serum 25(OH)D<20 ng/mL) was present in 670 subjects (51.0%), while vitamin D insufficiency (defined as serum 25(OH)D<30 ng/mL) was observed in 1187 subjects (90.3%). Older age (P<0.001), female gender (P<0.001), higher body mass index (P = 0.001), winter and spring seasons (compared to summer; P both<0.001), and passive smoking (P = 0.011) were independently associated with low serum 25(OH)D levels. After adjusting for potential confounders, serum 25(OH)D status had no association with asthma, rhinitis, eczema, atopy, or total serum IgE (all P>0.05).
  
  
  CONCLUSIONS
  Low serum 25(OH)D levels are remarkably common in this population sample of Asian children, suggesting that millions of children living in Taiwan may have suboptimal levels of vitamin D, which should be a matter of public health concern. Our results provides epidemiological evidence against the association of vitamin D status with various allergic diseases and atopy in Asian children.
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: 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, Illinois, United States of America; 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.
authors.forename: Jing-Long
authors.initials: JL
authors.lastname: Huang
authors.forename: Jing-Long
authors.initials: JL
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D044466:Asian People; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis / Q000453:epidemiology*; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D015999:Multivariate Analysis; D015995:Prevalence; D012044:Regression Analysis; D012621:Seasons; D012907:Smoking; D011795:Surveys and Questionnaires; D013624:Taiwan / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology
chemical_list: D014807:Vitamin D; D007073:Immunoglobulin E; C104450:25-hydroxyvitamin D