title: Reliability of self-reported sun exposure in Canadian women and estimation of lifetime exposure to vitamin D from sun and diet.
abstract: OBJECTIVE
  To assess the inter-method reliability of the Ovarian Cancer in Alberta (OVAL) survey developed to estimate adult vitamin D exposure from sun and diet for every tenth year, against the longer Geraldton Skin Cancer Prevention Survey (the assumed 'gold standard'). We also estimated total vitamin D exposure using the OVAL survey.
  
  
  METHODS
  A randomized crossover design to assess the inter-method reliability of sun exposure (OVAL v. Geraldton survey), using intra-class correlation and estimated total vitamin D exposure from sun and diet.
  
  
  METHODS
  Calgary, Alberta, Canada.
  
  
  METHODS
  Randomly selected women (n 90) aged 40-79 years.
  
  
  RESULTS
  The average lifetime sun exposure of 13,913 h (average 411 h/year) from the Geraldton survey was not significantly different from the 13,034 h (average 385 h/year) from the OVAL survey for periods with sufficient UV radiation to stimulate vitamin D production. The intra-class correlation coefficient for average lifetime sun exposure was 0.77 (95% CI 0.69, 0.86); the annual average was 0.60 (95% CI 0.47, 0.74). Estimated vitamin D from diet and supplements increased with age.
  
  
  CONCLUSIONS
  Our OVAL survey reliably estimated adult sun exposure relative to the Geraldton survey, suggesting that assessing sun exposure every tenth year is a reliable and efficient method for estimating sun contributions to lifetime vitamin D exposure.
authors.affiliation: 1 Division of Epidemiology and Biostatistics, Department of Internal Medicine, MSC10 5550, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA.
authors.forename: Linda S
authors.initials: LS
authors.lastname: Cook
authors.affiliation: 1 Division of Epidemiology and Biostatistics, Department of Internal Medicine, MSC10 5550, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA.
authors.forename: Bevin L
authors.initials: BL
authors.lastname: Moon
authors.affiliation: 1 Division of Epidemiology and Biostatistics, Department of Internal Medicine, MSC10 5550, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Dong
authors.affiliation: 2 Alberta Health Services, Calgary, Alberta, Canada.
authors.forename: Heather K
authors.initials: HK
authors.lastname: Neilson
mesh_terms: D000328:Adult; D000368:Aged; D000416:Alberta; D018592:Cross-Over Studies; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008875:Middle Aged; D015203:Reproducibility of Results; D057566:Self Report; D013472:Sunlight; D014807:Vitamin D / Q000008:administration & dosage* / Q000097:blood*
chemical_list: D014807:Vitamin D