John,
Grains have virtually no folic acid (and no B6 or B12). Vegetables have
plenty of folate and B6 - the name folic comes from foliage. B12 is from
animal foods only- some vegans get theirs from the left over poo fertiliser
on their root vegetables. (see archives of paleodiet for a reference on this
by Loren Cordain, look for B12). Mushrooms have trivial amounts of B12.
Ben