Vitamin B12

We're advised to use the methylated form of B12 as it's believed to be superior. This paper suggests that this is appropriate in methylation disorders but that it might be better to use hydroxycobalamine to avoid missing out on the form that we need for myelin formation.

11 Replies

  • I think using both is sometimes suggested. I have Hydroxycobalamin injections and also take the Methylcobalamin tablets :-)

  • Very interesting article, thanks for posting. PR

  • Very interesting article, thanks. :)

    Adenosylcobalamin can be bought without prescription as an oral supplement called dibencozide. I've never tried it myself.

  • An interesting article that conflicts with the advice often given on this site .Often said that that the non methyl form is used because it is cheaper. But seems we need both.

  • I've only had time to read the abstract so far, but I'm very dubious about the statement that oral supplementation has been proven to be comparable to IM...?

    Bit confused - I thought methylcobalamin was further metabolised to adenosylcobalamin in the body? From past reading and advice here, I understood the metabolic chain went hydroxo-methyl-adenosyl?

    I did take oral adenosyl -B12, two different brands, for about 3 months, with no noticeable effect, but then I have PA, and no IF.

  • My understanding is the same as yours, Hillwoman, that methyl is usually converted to adenosyl in the body. I believe that doesn't always happen for those with certain types of methylation issues, however.

    Anecdotally, I took sublingual methyl for about three weeks after realising hydroxo wasn't working for me (I assume due to MTHFR/methylation issues), and then started on sublingual adenosyl, reducing the methyl while I did so. I experienced a rush of energy after a couple of days, similar to the one I'd got when I started methyl, so from that I've deduced that, for some reason (my money is on something to do with MTHFR/methylation), I need both forms of active B12.

  • I must say I am very hazy on the whole MTHFR issue. Can one test for conversion issues? I've been off the boards for a few weeks and I feel as if I've forgotten a lot of what I thought I knew!

  • I know the problem - I feel I'm on top of a subject when I've just read up about it, but it all seems to leak out of my brain within a few days... :)

    I don't know if it's possible to test for conversion issues, but one can test for polymorphisms in the MTHFR gene which affect conversion. Most people who test privately appear to use an organisation called "23 and me" to do so.

    That said, I understand there can be issues with the methylation cycle and therefore with conversion even if one doesn't have a polymorphism of this gene.

  • Thanks for that. I really must investigate, brain leakage notwithstanding... ;)

  • Thanks so much for sharing this link. It makes extremely interesting reading, and reflects my experience that my body needs both active forms supplemented. The final sentence gave me a momentary panic about my B12 dosing regimen:

    "Only in the rare genetic disorders of conversion of vitamin B12 to its active coenzyme forms are the active forms to be used exclusively by the parenteral route."

    I wondered if I should be injecting. And then I realised the paper only looks at the efficacy of oral and injected supplements, not sublingual, nasal or transdermal. It seems I can happily continue avoiding needles for now! (And also, I don't think the inability to convert inactive to active efficiently is all that rare. It may often go unidentified, which is a different matter.)

  • I've just spent about 2 hours trying to find an answer to this and it's still not clear to me how the methyl version would convert to the adenosyl version. Methyl takes place in the cytosine and adenosyl in the mitochondria and, in fact, some of the detail is not yet know.

    So I've decided to use a combined methyl and adenosyl sub lingual form when I've finished my current methyl supplement to cover all bases.

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