title: Estimated intake of vitamin D and its interaction with vitamin A on lung cancer risk among smokers.
abstract: Data are very limited on vitamin D and lung cancer prevention in high-risk populations. The authors investigated whether estimated vitamin D intake was associated with lung cancer risk and whether effect modification by vitamin A existed among current/former heavy smokers and workers with occupational exposure to asbestos. A case-cohort study selected 749 incident lung cancers and 679 noncases from the Carotene and Retinol Efficacy Trial (CARET), 1988-2005. The active intervention was supplementation of 30 mg β-carotene + 25,000 IU retinyl palmitate/day. Baseline total intake including both diet (from food frequency questionnaire) and personal supplements (from brand names linked to the labeled potencies) was assessed. Hazard ratios (HRs) were estimated by Cox proportional hazard models. No significant association of total vitamin D intake with lung cancer was observed overall. However, total vitamin D intake ≥600 versus <200 IU/day was associated with a lower risk of non-small cell lung cancer among former smokers [HR = 0.36, 95% confidence interval (CI) = 0.13-0.96]. Total vitamin D intake ≥400 versus <400 IU/day was associated with a lower risk of total lung cancer among participants who received the CARET active intervention (HR = 0.56, 95% CI = 0.32-0.99) and among those who had total vitamin A intake ≥1,500 µg/day retinol activity equivalent (RAE; HR = 0.46, 95% CI = 0.23-0.91). The beneficial associations were attenuated among those who did not receive the CARET active intervention or who had total vitamin A intake <1,500 µg/day RAE (p-interaction = 0.02 for current smokers). Our observation suggests that vitamin A may assist vitamin D in preventing lung cancer among smokers.
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA; Department of Epidemiology, University of Washington, Seattle, WA.
authors.forename: Ting-Yuan David
authors.initials: TY
authors.lastname: Cheng
authors.forename: Gary E
authors.initials: GE
authors.lastname: Goodman
authors.forename: Mark D
authors.initials: MD
authors.lastname: Thornquist
authors.forename: Matt J
authors.initials: MJ
authors.lastname: Barnett
authors.forename: Shirley A A
authors.initials: SA
authors.lastname: Beresford
authors.forename: Andrea Z
authors.initials: AZ
authors.lastname: LaCroix
authors.forename: Yingye
authors.initials: Y
authors.lastname: Zheng
authors.forename: Marian L
authors.initials: ML
authors.lastname: Neuhouser
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D002986:Clinical Trials as Topic; D019587:Dietary Supplements; D004347:Drug Interactions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000178:diet therapy* / Q000209:etiology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D014801:Vitamin A / Q000008:administration & dosage* / Q000378:metabolism; D014807:Vitamin D / Q000008:administration & dosage* / Q000378:metabolism; D014815:Vitamins / Q000008:administration & dosage* / Q000378:metabolism
chemical_list: D014815:Vitamins; D014801:Vitamin A; D014807:Vitamin D
keywords: chemoprevention; estimated vitamin D intake; lung cancer; smoking; vitamin A