title: Prevalence of and risk factors for vitamin B(12) deficiency in patients with Crohn's disease.
abstract: BACKGROUND
  Crohn's disease (CD) can commonly involve the terminal ileum, which is the site of B(12) absorption. The aim of this study was to define the prevalence of vitamin B(12) abnormalities in a population with CD and to identify risk factors associated with B(12) abnormalities in CD.
  
  
  METHODS
  The medical records of 201 patients with CD evaluated at a tertiary care center were retrospectively reviewed to determine the prevalence of B(12) deficiency and to evaluate factors associated with B(12) deficiency. The prevalence of B(12) deficiency in a control population of 40 patients with ulcerative colitis was also assessed.
  
  
  RESULTS
  The prevalence of an abnormal serum B(12) concentration in patients with CD was 18.4% (95% confidence interval [CI] 13.1-23.8%) compared with 5% (95% CI, 0-11.8%) (P = 0.035) in ulcerative colitis controls. Risk factors for B(12) deficiency in patients with CD included prior ileal (odds ratio [OR], 7.22; 95% CI, 1.97-26.51) or ileocolonic (OR, 5.81; 95% CI, 2.09-16.12) resection and the need for ongoing medical therapy (OR, 2.59; 95% CI, 1.03-6.47). Neither disease location nor duration was independently associated with the risk of B(12) deficiency.
  
  
  CONCLUSIONS
  Vitamin B(12) abnormalities are common in patients with CD and patients with a prior ileal or ileocolonic resection are at particular risk. Routine screening for B(12) deficiency in patients with CD is warranted.
authors: University of Washington, Department of Medicine, Division of Gastroenterology, Seattle, WA 98195, USA.
authors: Peggy D
authors: PD
authors: Headstrom
authors: Stephen J
authors: SJ
authors: Rulyak
authors: Scott D
authors: SD
authors: Lee
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003082:Colectomy / Q000009:adverse effects; D003424:Crohn Disease / Q000150:complications* / Q000601:surgery; D005260:Female; D006801:Humans; D007082:Ileum / Q000601:surgery; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D014806:Vitamin B 12 Deficiency / Q000453:epidemiology* / Q000209:etiology; D014861:Washington / Q000453:epidemiology