RESULTS	Plasma folate concentrations plateaued at 3 mo with 108 % ( 95 % CI : 97.7 % , 120 % ) , 259 % ( 95 % CI : 240 % , 279 % ) , 460 % ( 95 % CI : 417 % , 503 % ) , and 142 % ( 95 % CI : 123 % , 162 % ) observed increases for the folic acid groups receiving 100 , 400 , and 4000 microg/d and 4000 microg/wk , respectively .\