title: Vitamin d deficiency in postmenopausal breast cancer survivors.
abstract: OBJECTIVE
  Breast cancer survivors (BCS) taking aromatase inhibitors (AIs) are at an increased risk for decreased bone density and fractures. Given the role vitamin D plays in bone metabolism, we examined the prevalence of and risk factors for vitamin D deficiency in a study of postmenopausal BCS on AIs.
  
  
  METHODS
  We collected data on 391 postmenopausal women with stage I-III breast cancer on AI therapy. Vitamin D levels were measured by radioimmunoassay from patients' sera; deficiency was defined as a level < 30 ng/mL. Multivariate models were created to assess risk factors for deficiency.
  
  
  RESULTS
  The median vitamin D level was 35 ng/mL (range 6.78-93.15), and 35% of women were vitamin D deficient. When adjusting for age and vitamin D supplementation, minority participants were more likely to be vitamin D deficient than white women, (adjusted odds ratio [AOR] 2.18, 95% confidence interval [CI]1.22-3.89, p=0.009). Both overweight (AOR 3.05, 95% CI 1.72-5.41, p<0.001) and obese participants (AOR 3.21, 95% CI 1.79-5.78, p<0.001) had higher deficiency rates than did normal weight participants.
  
  
  CONCLUSIONS
  Hypovitaminosis D is common in BCS, and those who are nonwhite or overweight are at a higher risk of deficiency despite taking vitamin D supplements.
authors.affiliation: Abramson Cancer Center, University of Pennsylvania Health System, Philadelphia, PA 19104, USA. claire.friedman@uphs.upenn.edu
authors.forename: Claire F
authors.initials: CF
authors.lastname: Friedman
authors.forename: Angela
authors.initials: A
authors.lastname: DeMichele
authors.forename: H Irene
authors.initials: HI
authors.lastname: Su
authors.forename: Rui
authors.initials: R
authors.lastname: Feng
authors.forename: Shiv
authors.initials: S
authors.lastname: Kapoor
authors.forename: Krupali
authors.initials: K
authors.lastname: Desai
authors.forename: Jun J
authors.initials: JJ
authors.lastname: Mao
mesh_terms: D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D011795:Surveys and Questionnaires; D017741:Survivors / Q000523:psychology / Q000706:statistics & numerical data; D014807:Vitamin D / Q000031:analogs & derivatives; D014808:Vitamin D Deficiency / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D