Soldato
Folic acid isn't B12....
I'd certainly see medical advice.
(-edit, it's been years since I looked at the B vitamin interactions, but I though there was something about large doses of the folate masking the deficiency in B12, thus making the condition actually worse, but ho-hum, as I say it has been years)
Specifically, it's C677T and A1298C of which I'm heterozygote for both, which is apparently rather unusual. Both combined can impact folate production significantly, so my B12 and homocysteine levels would be impacted quite badly.