title: The association between postdiagnosis dietary supplement use and total mortality differs by diet quality among older female cancer survivors.
abstract: BACKGROUND
  Dietary supplements are widely used by cancer survivors. However, health effects among older cancer survivors are unclear.
  
  
  METHODS
  We used the Iowa Women's Health Study, a prospective cohort study with 2,118 postmenopausal women with a confirmed cancer diagnosis (1986-2002), to evaluate the association between postdiagnosis dietary supplement use assessed in 2004 and subsequent all-cause mortality. Risk of death was evaluated using multivariable-adjusted Cox proportional hazards regression. We performed stratified analyses by diet quality score, dietary micronutrient intake, and perceived general health.
  
  
  RESULTS
  Through 2010, 608 deaths were identified. Approximately 85% of the cancer survivors used dietary supplements. Overall supplement use and multivitamin use were not associated with mortality. Iron supplement use was associated with 39% higher risk of death [95% confidence interval (CI), 1.09-1.77]. This association was stronger among survivors with deteriorating general health. Folic acid supplement use was associated with higher risk of death, only among survivors reporting low-quality diets (HR, 2.33; 95% CI, 1.33-4.08; P interaction = 0.006). Multivitamin use and using a greater number of supplements was associated with a trend towards higher mortality only among those with poor diet quality. Using vitamin E supplements in combination with multivitamin was associated with lower risk of death only among survivors with higher dietary vitamin E intake (HR, 0.61; 95% CI, 0.39-0.94; P interaction = 0.02).
  
  
  CONCLUSIONS
  Postdiagnosis supplement use was associated with higher mortality among older female cancer survivors with poor general health and/or poor dietary intake.
  
  
  CONCLUSIONS
  The association between postdiagnosis dietary supplement use and mortality may differ by diet quality and health status among older female cancer survivors.
authors.affiliation: Authors' Affiliations: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota; Department of Epidemiology, Mailman School of Public Health, Columbia University; Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York; and Department of Epidemiology and Biostatistics, School of Public Health and Health Services, George Washington University, Washington, DC.
authors.forename: Maki
authors.initials: M
authors.lastname: Inoue-Choi
authors.forename: Heather
authors.initials: H
authors.lastname: Greenlee
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Oppeneer
authors.forename: Kim
authors.initials: K
authors.lastname: Robien
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000178:diet therapy* / Q000401:mortality; D004032:Diet / Q000592:standards*; D019587:Dietary Supplements / Q000706:statistics & numerical data*; D005247:Feeding Behavior; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009026:Mortality / Q000639:trends*; D011379:Prognosis; D011446:Prospective Studies; D011786:Quality Control; D015996:Survival Rate; D014815:Vitamins / Q000008:administration & dosage*; D016387:Women's Health
chemical_list: D014815:Vitamins