This whole folate & Vit. B thing is of great interest to me, but I can't seem to get a clear idea anywhere of exactly how you find out your levels of each, what actually constitutes a deficiency, and how much supplementation to take if deficient. I participated in a very interesting & informative forum discussion related to the MTHFR mutations (which I do have) , but ended up with no clear answer of what to do. Anybody here have any answers? Many thanks.