title: Vitamin D status of Canadians employed in northern latitudes.
abstract: BACKGROUND
  Vitamin D deficiency and insufficiency are prevalent worldwide, but relatively few studies have examined vitamin D status in working populations.
  
  
  OBJECTIVE
  To assess the prevalence of vitamin D deficiency and insufficiency in Canadian workers and investigate risk factors in this population.
  
  
  METHODS
  A cross-sectional study using data from a health programme enrolling workers mostly from Northern Alberta, Canada. As part of the programme, volunteers were invited to complete a lifestyle questionnaire. Blood was taken to determine plasma 25-hydroxyvitamin D (25(OH)D) levels. Logistic and linear regressions were used to investigate the relationships between individual characteristics and vitamin D status.
  
  
  RESULTS
  Between October 2007 and December 2012, 6101 eligible workers enrolled in the health programme. The prevalence of vitamin D deficiency (plasma 25(OH)D, levels <27.5 nmol/l) and insufficiency (<37.5 nmol/l) were 3 and 8%, respectively. Male employees were significantly more likely to be vitamin D deficient and insufficient than females. Residing at a more northern latitude increased the likelihood of vitamin D deficiency and insufficiency. Age, assessments made in summer, better general health and physical activity and use of vitamin D supplementation were all related to lower likelihood of deficiency and insufficiency.
  
  
  CONCLUSIONS
  Vitamin D deficiency and insufficiency are a concern in this sample of Canadian workers. Vitamin D supplementation is recommended to reduce the prevalence of deficiency and insufficiency in this group.
authors.affiliation: School of Public Health, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Y-S
authors.initials: YS
authors.lastname: Chao
authors.forename: L
authors.initials: L
authors.lastname: Brunel
authors.forename: P
authors.initials: P
authors.lastname: Faris
authors.forename: P J
authors.initials: PJ
authors.lastname: Veugelers
mesh_terms: D000328:Adult; D000367:Age Factors; D000416:Alberta / Q000453:epidemiology; D003430:Cross-Sectional Studies; D019587:Dietary Supplements; D004651:Employment; D015444:Exercise; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012621:Seasons; D012737:Sex Factors; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D014937:Work
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: 25-hydroxyvitamin D; Canadian workers; deficiency; insufficiency; vitamin D.