Bioavailablity of different forms of B12

[Sleepybunny]

Hi,

Came across this article about comparing bioavailability of different forms of B12 and thought some of you might find it interesting.

ncbi.nlm.nih.gov/pmc/articl...

Apologies if it's been posted before.

[wedgewood]

Thanks for that link Sleepybunny .. The more knowledge the better ! -At the start of the article, Methylcobalamin, Hydroxocobalamin and Adenosylcobalamin are listed as “ natural cobalamins , and at the end ,after the last Conclusion , Methylcobalamin is mentioned as being. “ the least costly form of natural B12 “ . I don’t think that is true . Hydroxocobalamin is the least costly of those which are called “natural cobalamins “ It’s great for us that you find such nuggets of information for us ! Thanks

[Gambit62 Administrator in reply to wedgewood]

it depends on the format - methyl may well be the cheapest for use as tablets but hydroxocobalamin is more stable and cheaper to store when suspended in liquid - as in injections.

[wedgewood in reply to Gambit62]

Thanks for that. I don’t think that I’ve ever seen Hydroxocobalamin in vitamin tablets or additives in say cereals etc . It’s always been cynocobalamin or Methylcobalamin. There must be a commercial reason though .

[helvella in reply to wedgewood]

Hydroxo- are available and I take them. 😀

[wedgewood in reply to helvella]

Thanks . It’s probably just coincidence that I’ve never seen them . I lean something every day ( and forget half a dozen !)

[Hamayeshguy in reply to wedgewood]

There is in spray form available

[Hamayeshguy in reply to wedgewood]

It depends in the grade if end product and how to extract pure form for pharmaceutical grade. I think hydroxy can better be extracted because it can be precipitated as salt and purified. Methyl probably is the most expensive form because methy group is almost neutral in most extractions so mostly are just in edible form

[wedgewood]

Also forgot how to spell “learn” .

[Hamayeshguy]

So where can we buy methylcobalamine vialfor injection. This article is saying it depends on enzyme presence and even just one form may not raise B12 serum. What about we use all three forms together? And also denying claims that hydroxy form has less effective in methylation process. But some articles claim cyanide form is superior form because it's not natural and no antibody can be made for that. It's really complicated and should be done based in trial and error.

[Jengastar]

Really interesting thanks. I was taking SAMe supplements on advice of nutritionist but didn’t realise it was involved in the B12 process too. Think I need to a few times and after a morning coffee to get all the info out of it!

[helvella]

I found most interesting the bit that starts:

Newly Discovered Roles for B12 as an Active Cofactor in Nitric Oxide Metabolism

Glutathionyl-cobalamin (GSHCbl) is an intermediate in cobalamin metabolism.

I have long believed that B12 affects other pathways. (Indeed, the use of hydroxo- for smoke inhalation is one obvious other way in which it affects us.)