title: The effect of folic acid supplementation on the risk for cancer or dysplasia in ulcerative colitis.
abstract: OBJECTIVE
  Two case-control studies have shown that folate may protect against neoplasia in ulcerative colitis. This historical cohort study was performed to better define this association.
  
  
  METHODS
  The records of 98 patients with ulcerative colitis who had disease proximal to the splenic flexure for at least 8 years were reviewed. Documented folate use of at least 6 months was deemed a positive exposure.
  
  
  RESULTS
  Of the patients, 29.6% developed neoplasia and 40.2% took folate supplements. The adjusted relative risk (RR) of neoplasia for patients taking folate was 0.72 (95% confidence interval [CI], 0.28-1.83). The dose of folate varied with the risk of neoplasia (RR, 0.54 for 1.0 mg folate; RR, 0.76 for 0.4 mg folate in a multivitamin compared with patients taking no folate). Folate use also varied with the degree of dysplasia (RR for cancer, 0.45; RR for high-grade dysplasia, 0.52; RR for low-grade dysplasia, 0.75 compared with patients with no dysplasia) (P = 0.08).
  
  
  CONCLUSIONS
  Although not statistically significant, the RR for folate supplementation on the risk of neoplasia is < 1 and shows a dose-response effect, consistent with previous studies. Daily folate supplementation may protect against the development of neoplasia in ulcerative colitis.
authors.affiliation: Department of Gastroenterology, Cleveland Clinic Foundation, Ohio, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Lashner
authors.forename: K S
authors.initials: KS
authors.lastname: Provencher
authors.forename: D L
authors.initials: DL
authors.lastname: Seidner
authors.forename: A
authors.initials: A
authors.lastname: Knesebeck
authors.forename: A
authors.initials: A
authors.lastname: Brzezinski
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003093:Colitis, Ulcerative; D015179:Colorectal Neoplasms / Q000517:prevention & control*; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage*; D006397:Hematinics / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D016017:Odds Ratio; D011230:Precancerous Conditions / Q000517:prevention & control*; D018570:Risk Assessment
chemical_list: D006397:Hematinics; D005492:Folic Acid