The effect of folic acid supplementation on the risk for cancer or dysplasia in ulcerative colitis

Gastroenterology. 1997 Jan;112(1):29-32. doi: 10.1016/s0016-5085(97)70215-4.


Background & aims: 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.

MeSH terms

  • Adult
  • Cohort Studies
  • Colitis, Ulcerative*
  • Colorectal Neoplasms / prevention & control*
  • Female
  • Folic Acid / administration & dosage*
  • Hematinics / administration & dosage*
  • Humans
  • Male
  • Odds Ratio
  • Precancerous Conditions / prevention & control*
  • Risk Assessment


  • Hematinics
  • Folic Acid