title: Non-Western immigrant children have lower 25-hydroxyvitamin D than children from Western families.
abstract: OBJECTIVE
  To determine if children aged 1-6 years from non-Western immigrant families have lower serum 25-hydroxyvitamin D (25(OH)D) levels than children from Western-born families and examine which factors influence this relationship.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Toronto, Canada.
  
  
  METHODS
  Healthy children (n 1540) recruited through the TARGet Kids! practice-based research network. Serum 25(OH)D concentrations of non-Western immigrants were compared with those of children from Western-born families. Children from non-Western immigrant families were defined as those born, or their parents were born, outside a Western country. Univariate and multiple linear regression analyses were used to identify factors which might influence this relationship.
  
  
  RESULTS
  Median age was 36 months, 51 % were male, 86 % had 'light' skin pigmentation, 55 % took vitamin D supplements, mean cow's milk intake was 1·8 cups/d and 27 % were non-Western immigrants. Median serum 25(OH)D concentration was 83 nmol/l, with 5 % having 25(OH)D < 50 nmol/l. Univariable analysis revealed that non-Western immigrant children had serum 25(OH)D lower by 4 (95 % CI 1·3, 8·0) nmol/l (P = 0·006) and increased odds of 25(OH)D < 50 nmol/l (OR = 1·9; 95 % CI 1·3, 2·9). After adjustment for known vitamin D determinants the observed difference attenuated to 0·04 (95 % CI -4·8, 4·8) nmol/l (P = 0·99), with higher cow's milk intake (P < 0·0001), vitamin D supplementation (P < 0·0001), summer season (P = 0·008) and increased age (P = 0·04) being statistically significant covariates. Vitamin D supplementation was the strongest explanatory factor of the observed difference.
  
  
  CONCLUSIONS
  There is an association between non-Western immigration and lower 25(OH)D in early childhood. This difference appears related to known vitamin D determinants, primarily vitamin D supplementation, representing opportunities for intervention.
authors.affiliation: 1Department of Nutritional Sciences,University of Toronto,Toronto,ON,Canada.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Omand
authors.affiliation: 1Department of Nutritional Sciences,University of Toronto,Toronto,ON,Canada.
authors.forename: Pauline B
authors.initials: PB
authors.lastname: Darling
authors.affiliation: 3Department of Pediatrics,University of Toronto,Toronto,ON,Canada.
authors.forename: Patricia C
authors.initials: PC
authors.lastname: Parkin
authors.affiliation: 3Department of Pediatrics,University of Toronto,Toronto,ON,Canada.
authors.forename: Catherine S
authors.initials: CS
authors.lastname: Birken
authors.affiliation: 4Department of Pediatric Medicine and the Pediatric Outcomes Research Team,The Hospital for Sick Children,Toronto,ON,Canada.
authors.forename: Marina
authors.initials: M
authors.lastname: Khovratovich
authors.affiliation: 7Keenan Research Centre,Li Ka Shing Knowledge Institute,St. Michael's Hospital,Toronto,ON,Canada.
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Thorpe
authors.affiliation: 4Department of Pediatric Medicine and the Pediatric Outcomes Research Team,The Hospital for Sick Children,Toronto,ON,Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Carsley
authors.affiliation: 3Department of Pediatrics,University of Toronto,Toronto,ON,Canada.
authors.forename: Julie
authors.initials: J
authors.lastname: DeGroot
authors.affiliation: 1Department of Nutritional Sciences,University of Toronto,Toronto,ON,Canada.
authors.forename: Jonathon L
authors.initials: JL
authors.lastname: Maguire
mesh_terms: D000367:Age Factors; D000818:Animals; D002170:Canada; D002648:Child; D002675:Child, Preschool; D004032:Diet; D019587:Dietary Supplements; D054242:Emigrants and Immigrants; D005260:Female; D054624:Health Status Disparities; D006801:Humans; D007223:Infant; D008297:Male; D008892:Milk; D012621:Seasons; D012880:Skin Pigmentation; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D