title: Determinants of vitamin D status in pregnant women and neonates.
abstract: Evidence suggests a beneficial effect of vitamin D on perinatal health; however, low vitamin D status is prevalent in pregnant women and neonates. The objective was to determine factors that are associated with vitamin D status of mothers in early pregnancy and neonates.
  
  
  
  The study comprised 1,635 pregnant women from Quebec City and Halifax, Canada, 2002-2010. Vitamin D status was based on the concentration of 25-hydroxy-vitamin D [25(OH)D] determined with a chemiluminescence immunoassay in maternal sera collected at a median of 15 weeks' gestation and in neonatal cord sera at delivery. A questionnaire with information on potential determinants was completed midpregnancy.
  
  
  
  A total of 44.8% of mothers and 24.4% of neonates had 25(OH)D concentrations &lt;50 nmol/L. Adjusted mean (95% confidence interval) maternal 25(OH)D levels were higher in summer than in winter by 16.1 nmol/L (13.6-18.7), and in those in the highest versus the lowest category of education by 6.1 nmol/L (0.5-11.8), in BMI &lt;25 kg/m2 versus BMI ≥35 kg/m2 by 8.2 nmol/L (4.0-12.3), and in the highest versus the lowest physical activity category by up to 9.5 nmol/L (2.9-16.1). Determinants of neonatal 25(OH)D levels were similar but also included maternal age, dairy intake, supplement use and 25(OH)D level.
  
  
  
  This study suggests that vitamin D status of pregnant women and/or neonates might be improved through supplementation, adequate dairy intake, a move towards a healthy pre-pregnancy body weight, and participation in physical activity. Controlled studies are needed to determine the effectiveness of interventions aimed at these factors.
authors.affiliation: Perinatal Epidemiology Research Unit, Departments of Obstetrics & Gynaecology and Pediatrics, Dalhousie University and IWK Health Centre, Halifax, NS. christy.woolcott@iwk.nshealth.ca.
authors.forename: Christy G
authors.initials: CG
authors.lastname: Woolcott
authors.forename: Yves
authors.initials: Y
authors.lastname: Giguère
authors.forename: Hope A
authors.initials: HA
authors.lastname: Weiler
authors.forename: Anne
authors.initials: A
authors.lastname: Spencer
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Forest
authors.forename: B Anthony
authors.initials: BA
authors.lastname: Armson
authors.forename: Linda
authors.initials: L
authors.lastname: Dodds
mesh_terms: D000328:Adult; D002170:Canada / Q000453:epidemiology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D009752:Nutritional Status; D011247:Pregnancy; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D