title: A prospective study of plasma ascorbic acid concentrations and breast cancer (United States).
abstract: OBJECTIVE
  To investigate the association between prediagnostic plasma ascorbic acid concentrations and subsequent breast cancer risk in a nested case-control study.
  
  
  METHODS
  Female volunteer residents of Washington County, MD, donated 14,625 non-fasting blood samples in 1989. Incident breast cancer cases (n = 115) and controls (n = 115) were matched by age, menopausal status at donation, and date and hour of blood donation.
  
  
  RESULTS
  Median ascorbic acid concentrations were similar between cases and controls (1.44 mg/dl vs. 1.39 mg/dl. p = 0.78). There was no evidence for a dose-response relationship between higher plasma ascorbic acid concentrations and breast cancer risk [highest vs. lowest fifths: ORadjusted = 0.90, Ptrend = 0.98).
  
  
  CONCLUSIONS
  Findings from this prospective study do not suggest a protective association between prediagnostic plasma ascorbic acid concentrations and breast cancer risk in the subsequent 5 years of follow-up.
authors.affiliation: Department of Epidemiology, Johns Hopkins University, School of Hygiene and Public Health, Baltimore, MD 21205, USA.
authors.forename: K
authors.initials: K
authors.lastname: Wu
authors.forename: K J
authors.initials: KJ
authors.lastname: Helzlsouer
authors.forename: A J
authors.initials: AJ
authors.lastname: Alberg
authors.forename: G W
authors.initials: GW
authors.lastname: Comstock
authors.forename: E P
authors.initials: EP
authors.lastname: Norkus
authors.forename: S C
authors.initials: SC
authors.lastname: Hoffman
mesh_terms: D001205:Ascorbic Acid / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008396:Maryland / Q000453:epidemiology; D008593:Menopause; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D001205:Ascorbic Acid