Actually I read that one of the key advantages of methylfolate is that unlike folic acid it does not mask the B12 deficiency which is another plus. I use the Solgar branded Folate -which sadly is not liscenced in the UK so I have to go to creative lengths to source it. I only take the RDA of 400 micrograms-. I was folate deficient BUT just 2 weeks on this amount put me in the mid range of normal and I continue to take it as I dont eat folate rich everyday and I am VERY anaemic...