This is where I need a good degree of clarification. Is it possible for some people not to convert hydroxy into useable methyl and adeno because of some sort disfunctioning pathway? Therefore making methyl work better for them or is it a case of which gets into the cells more easily for that individual. Or is there zero difference if both have been administered IM or SUBQ(either method is good) imo.
Thanks all
No.
Hydroxocobalamin isn't converted to methylcobalamin.
Whenever B12 of any type enters the cell it is converted to cob(II)alamin, be it hydroxo, methyl, cyano, or adenosyl. This process is carried out by the same enzyme MMACHC.
ncbi.nlm.nih.gov/pmc/articl...
Got it .... so it's just about personal preferences then, which one the individual tolerates the best. Correct?
Also why do people on forums keep saying if you SI methyl you need to take adenosyl too? Surely this is false too from what you are saying? Thanks again.
Yes, it's total codswallop. Somebody wrote that on Wikipedia and it's spread all over the interwebs, even though it's been corrected.
There is at least one reported medical case of a patient who couldn't convert methyl to adenosyl - not really sure how it worked from a biochemical perspective - but it is extremely rare - insisting on both adenosyl and methyl is definitely erring on the cautious side.
I take hydroxy, and it seems to help re typical B12 issues.
Self injecting methylcobalmin- some advice please.
Oral v injection 
Serum v active b12 confusion 
cobalamin v methylcobalamin sublinguals
