•DBPC Trial 1021 men and women (av. age 57 yrs)
•All had had a colorectal adenoma
•Folic acid, FA, 1000 ug/day or placebo for 5 yrs
•Surveillance colonoscopies at 3ys and 5 yrs
•Adenomas: FA vs Placebo: 44.1% vs 42.4% (3yrs) and
41.9% vs 37.2% (5yrs)