title: Determinants of vitamin D status in young children: results from the Belgian arm of the IDEFICS (Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants) Study.
abstract: OBJECTIVE
  To describe the vitamin D status of Belgian children and examine the influence of non-nutritional determinants, in particular of anthropometric variables.
  
  
  METHODS
  Cross-sectional data of Belgian participants of the EU 6th Framework Programme IDEFICS (Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants) Study.
  
  
  METHODS
  25-Hydroxyvitamin D (25(OH)D) was measured using RIA. Vitamin D status was categorized as deficient (<25 nmol/l), insufficient (25-50 nmol/l), sufficient (50-75 nmol/l) and optimal (≥75 nmol/l). Anthropometric measurements included height, weight, waist and hip circumferences and triceps and subscapular skinfold thicknesses.
  
  
  METHODS
  Children (n 357) aged 4-11 years.
  
  
  RESULTS
  Serum 25(OH)D ranged from 13·6 to 123·5 nmol/l (mean 47·2 (sd 14·6) nmol/l); with 5 % deficient, 53 % insufficient, 40 % sufficient and 2 % optimal. No significant differences were found by age and gender. Significant differences in 25(OH)D were observed for month of sampling (P < 0·001), number of hours playing outside per week (r = 0·140), weight (r = -0·121), triceps (r = -0·112) and subscapular (r = -0·119) skinfold thickness, sum of two skinfold thicknesses (r = -0·125) and waist circumference (r = -0·108). Linear regression analysis of 25(OH)D adjusted for age, month of sampling and hours playing outside per week suggested that (i) weight, (ii) BMI Z-score, (iii) waist circumference and (iv) triceps and subscapular skinfold thickness (as well as the sum of both) independently influenced 25(OH)D.
  
  
  CONCLUSIONS
  The majority of Belgian children had a suboptimal vitamin D status, with more than half having an insufficient status in winter and spring. Month of the year, weekly number of hours playing outside and body composition - both central and abdominal obesity - were identified as important determinants of vitamin D status in Belgian children.
authors.affiliation: Department of Public Health, Ghent University, UZ 2 Blok A, De Pintelaan 185, B-9000 Ghent, Belgium. Isabelle.Sioen@UGent.be
authors.forename: Isabelle
authors.initials: I
authors.lastname: Sioen
authors.forename: Theodora
authors.initials: T
authors.lastname: Mouratidou
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Kaufman
authors.forename: Karin
authors.initials: K
authors.lastname: Bammann
authors.forename: Nathalie
authors.initials: N
authors.lastname: Michels
authors.forename: Iris
authors.initials: I
authors.lastname: Pigeot
authors.forename: Barbara
authors.initials: B
authors.lastname: Vanaelst
authors.forename: Krishna
authors.initials: K
authors.lastname: Vyncke
authors.forename: Stefaan
authors.initials: S
authors.lastname: De Henauw
mesh_terms: D000273:Adipose Tissue; D001530:Belgium / Q000453:epidemiology; D001824:Body Constitution; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D056128:Obesity, Abdominal / Q000150:complications; D010988:Play and Playthings; D015995:Prevalence; D012016:Reference Values; D012044:Regression Analysis; D012307:Risk Factors; D012621:Seasons; D013472:Sunlight; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology / Q000209:etiology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D