title: Determination of the minimal essential serum folate concentration for reduced risk of colorectal adenoma.
abstract: OBJECTIVE
  There are no data regarding basal folate levels in patients without colorectal adenoma. This study aimed to determine the minimum serum folate concentration that associates with reduced risk of colorectal adenoma.
  
  
  METHODS
  1510 consecutive patients underwent total colonoscopy for suspected colorectal lesions after barium enema examination. Prior to colonoscopy, history of alcohol consumption was noted and blood serum analyzed for folate and vitamin B12 levels. Polypoid lesions were evaluated histologically. We excluded patients with anemia, history of colonoscopy, overconsumption of alcohol, or malignancies. In all, 458/1510 patients (male/female; 258/200, 40-75 years) were determined eligible. Variables were compared between patients with adenoma and those without adenoma.
  
  
  RESULTS
  Serum folate concentration was the variable with the most significant statistical variation between males with adenoma (8.0 ng/ml) and males without adenoma (9.2) (p = 0.001). Serum folate concentrations in females with adenoma did not differ significantly from those in females without adenoma (10.7 versus 10.9). When subjects were stratified into groups according to serum folate, we found no significant difference in the prevalence of adenoma in patients with folate levels greater than 8.0 ng/ml.
  
  
  CONCLUSIONS
  Patients with serum folate concentrations above 8.0 ng/ml had the lowest risk of developing colorectal adenoma.
authors: Department of Internal Medicine, Division of Gastroenterology, Nippon Medical School, 1-1-5, Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan. s-fujimori@nms.ac.jp
authors: Shunji
authors: S
authors: Fujimori
authors: Katya
authors: K
authors: Gudis
authors: Yoko
authors: Y
authors: Takahashi
authors: Makoto
authors: M
authors: Kotoyori
authors: Atsushi
authors: A
authors: Tatsuguchi
authors: Yoshiharu
authors: Y
authors: Ohaki
authors: Choitsu
authors: C
authors: Sakamoto