Folic acid is not needed in large doses. I do not take a large dose of it. In fact, I do not take an individual supplement of folic acid. I take the amount normally included in a B-100 complex and a multi-vitamin. I just checked. The total is 1200 mcgs. My blood test shows my folate levels to be optimum, basically, at the high end of the recommended blood level.

You posted <I am part of a chronic fatigue syndrome forum and it has recently been agreed upon that folic acid definitely is bad for people with compromised immunity, which is definitely abundant in those with head injuries. >

PCS subjects do not necessarily have compromised immune systems. Where did you get that information?

What do you mean by brain fog and what dose of folic acid did your doctor suggest?