I had a B12 test that came back 163 pg/mL. Folate is in range. I've decided to pay for an MNA test to see just how serious this is but I've begun to supplement with very small amounts of sublingual B12 for a few weeks. I have difficulty with both methylcobalamin (it makes me very tired, almost groggy) and hydroxycobalamin (gives me energy and focus but a bad headache); thus the very low levels of supplementation. My most immediate question is how much the low supplementation would affect the MMA results and how long I should wait after my last use (tiny amt of hydroxycobalamin yesterday) to get the MMA test since I don't want to waste my money -- it's an expensive test.
My second question (maybe best for another post) is whether others have had these types of reactions to B12. For anyone familiar with genetics, I am COMT V158M and COMT V62H homozygous, heterozygous for MTHFR 1298C and no mutation on MTHFR c677T.