title: Predicted vitamin D status and pancreatic cancer risk in two prospective cohort studies.
abstract: BACKGROUND
  Studies evaluating vitamin D status in relation to pancreatic cancer risk have yielded inconsistent results.
  
  
  METHODS
  We prospectively followed 118 597 participants in the Nurses' Health Study and Health Professionals Follow-up Study from 1986 to 2006. We calculated a 25-hydroxyvitamin D (25(OH)D) score from known predictors of vitamin D status for each individual and then examined the predicted 25(OH)D levels in relation to pancreatic cancer risk. Relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards models adjusted for age, sex, race, height, smoking, and diabetes. We then further adjusted for body mass index (BMI) and physical activity in a sensitivity analysis.
  
  
  RESULTS
  During 20 years of follow-up, we identified 575 incident pancreatic cancer cases. Higher 25(OH)D score was associated with a significant reduction in pancreatic cancer risk; compared with the lowest quintile, participants in the highest quintile of 25(OH)D score had an adjusted RR of 0.65 (95% CI=0.50-0.86; P(trend)=0.001). Results were similar when we further adjusted for BMI and physical activity.
  
  
  CONCLUSIONS
  Higher 25(OH)D score was associated with a lower risk of pancreatic cancer in these two prospective cohort studies.
authors.affiliation: Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA. ying.bao@channing.harvard.edu
authors.forename: Y
authors.initials: Y
authors.lastname: Bao
authors.forename: K
authors.initials: K
authors.lastname: Ng
authors.forename: B M
authors.initials: BM
authors.lastname: Wolpin
authors.forename: D S
authors.initials: DS
authors.lastname: Michaud
authors.forename: E
authors.initials: E
authors.lastname: Giovannucci
authors.forename: C S
authors.initials: CS
authors.lastname: Fuchs
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D015999:Multivariate Analysis; D010190:Pancreatic Neoplasms / Q000453:epidemiology*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D044469:Racial Groups; D012307:Risk Factors; D012727:Sex Characteristics; D012907:Smoking / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
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