Dr. McDougall's Online Discussion Board

Jeff,

Hope all is well with you. I thought I remembered reading here that the Methyl version of B-12 may not raise serum B-12 levels?
If so - do you recall the reference?

Thanks in advance,

Russ.

RawDad wrote:Jeff,

Hope all is well with you. I thought I remembered reading here that the Methyl version of B-12 may not raise serum B-12 levels?
If so - do you recall the reference?

Thanks in advance,

Russ.

Thanks

There has been quite a bit of discussion over the last few years and several studies on which is the best form. It is like a ping-pong game. However, I don't recall one in regard to your question. Methyl is usually the one you see recommended and said to be these best form.

You may find stories (maybe even in these forums) of people having success (or not) with different forms.

Part of the problem is the industry is unregulated and you don't always know what it is in your pill.

For a while, methyl was being touted as the superior form, however, a 2015 comparison showed no benefit
https://www.ncbi.nlm.nih.gov/pubmed/25820384

And this 2017 study showed it might be individual based on genes.
https://www.ncbi.nlm.nih.gov/pubmed/28223907

And here is a recent review on veg/vegans
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5188422/

On concerns with Cyano
viewtopic.php?f=7&t=58974&p=593839&#p593839

In the end, my position has been get your levels checked, take a (hopefully independently tested) form and if what you are doing is not working, switch products or forms.

One thing I have noticed (and this is anecdotally and may be a result of genetic variations I cant test for) but I have seem similar level of cyano raise levels of B12 better then the others in the same individual.

Hope that helps

In Health
Jeff

Thanks Jeff

JeffN wrote:One thing I have noticed (and this is anecdotally and may be a result of genetic variations I cant test for) but I have seem similar level of cyano raise levels of B12 better then the others in the same individual.

This recent study verifies my experience.

Efficacy of supplementation with methylcobalamin and cyancobalamin in maintaining the level of serum holotranscobalamin in a group of plant-based diet (vegan) adults

Exp Ther Med. 2021 Sep; 22(3): 993.
Published online 2021 Jul 14. doi: 10.3892/etm.2021.10425

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8311243/

Abstract
Plant-based nutrition has become extremely popular in the contemporary era. Its positive effects are sustained by many studies, but one of its risks is that it is almost completely devoid of vitamin B12. In the present study, we analyzed the effects of two types of vitamin B12 supplements, cyancobalamin and methylcobalamin on the level of active serum vitamin (holotranscobalamin) in a group of Romanian individuals (n=42) following a (vegan) plant-based diet. The results revealed that cyancobalamin gives better results in maintaining B12, as quantified by the holotranscobalamin value (median=150 pcg/l) when compared with methylcobalamin (median=78.5 pcg/l). The frequency of administration, regardless of the quantity in one dose, is another important factor in maintaining the holotranscobalamin level within suitable limits. More frequent intakes give more optimal results. Vegans trying to supplement with alternative products (algae, kombucha, other fermented products), had the lowest levels of holotranscobalamin, always bellow the recommended level of 35 pcg/l (median=29 pcg/l). Vegans must be educated on B12 supplementation, about the pharmaceutical forms on the market and their performances and on choosing the optimal plan in order to avoid the onset of B12 deficiency.

Cobalamin coenzyme forms are not likely to be superior to cyano- and hydroxyl-cobalamin in prevention
or treatment of cobalamin deficiency
Mol. Nutr. Food Res. 2015, 59, 1364–1372 REVIEW
DOI 10.1002/mnfr.201500019

Full text
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4692085/

Abstract
Methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl) are coenzymes for methionine synthase and methylmalonyl-CoA mutase, respectively. Hydroxylcobalamin (HOCbl) and cyanocobalamin (CNCbl) are frequently used for supplementation. MeCbl and AdoCbl have recently emerged as alternative forms in supplements. In the light of metabolic transformation of Cbl into its cofactor forms, this review discusses current evidence on efficacy and utility of different Cbl forms in preventing or treating Cbl deficiency. Cbl-transporting proteins bind and mediate the uptake of all aforementioned forms of Cbl. After internalization and lysosomal re- lease, Cbl binds to the cytosolic chaperon MMACHC that is responsible for (i) flavin-dependent decyanation of [CN-Co3+]Cbl to [Co2+]Cbl; (ii) glutathione-dependent dealkylation of MeCbl and AdoCbl to [Co2+/1+]Cbl; and (iii) glutathione-dependent decyanation of CNCbl or reduc- tion of HOCbl under anaerobic conditions. MMACHC shows a broad specificity for Cbl forms and supplies the Cbl2+ intermediate for synthesis of MeCbl and AdoCbl. Cobalamin chemistry, physiology, and biochemistry suggest that MeCbl and AdoCbl follow the same route of intracel- lular processing as CNCbl does. We conclude that supplementing MeCbl or AdoCbl is unlikely to be advantageous compared to CNCbl. On the other hand, there are obvious advantages of high parenteral doses (1–2 mg) of HOCbl in treating inborn errors of Cbl metabolism.