Hello,
After taking sublingual methylcobalamin daily for many years now and only ever having levels of c. 200-400 in my annual blood results I noticed this article:
nature.com/ejcn/journal/v69...
Does anybody recommend switching to this...
cytoplan.co.uk/vitamin-b12-...
I am pregnant so I am not really willing to just 'give it a go' and see what happens to my levels.
??
I think that you need to be tested for Pernicious Anaemia . You don't mention any symptoms though . Do you have any , or do you feel well ?
most people don't have a problem converting methyl to adenosyl but a few do and it would be those people who would really need to either use hydroxo/cyano or mix methyl and adenosyl.
This doesn't explain why your B12 levels continue to be bouncing along the bottom - that looks like it is probably an absorption problem - the doses you are taking are presumably very high so even with an absorption problem enough may be getting through to keep you bouncing along but long term you really need to sort out what the absorption problem is - could be PA but there are others - such as coeliacs and crohn's.
and wedgewood is right about the need to look at symptoms.
ncbi.nlm.nih.gov/pubmed/258...
"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"
Hi smelinoir. Agree with the comments of others. However, B12 deficency (whether from PA or from another cause) is a complex condition and often co-exists with other deficencies (I.e. Ferritin, folate, vitamin D etc.) which can make you feel quite ill, and are certainly things that should be tested by your GP (including FBC, and anti-IF antibodies). Folate levels are particularly important for those who are expecting.
Suggest that as you're expecting the best thing to do would be to go along to your GP and go through all this with him / her, starting with your continued low B12 levels and perhaps a B12 deficency symptom checklist.
This can be found in the PAS pinned posts to the right of this page when you log on...along with lots of other useful information about B12 deficency and pernicious anaemia. Well worth a read because GP's are usually ill-informed about both B12 deficency and PA.
It's also worth noting that if you have autoimmune conditions in your family, then there is a higher liklihood that you could also develop one (i.e. PA is an autoimmune condition).
Again, as you are expecting, please do see your GP to discuss your health issues and any potential vitamin and mineral supplement requirements. And do post again if you need any further help or advice.
Good luck 👍
Many thanks for all of your comments. I will probably look at changing my supplements to a variety of forms just to cover all bases.
In response to some of the comments about other concerns, I have been battling with the medical profession for many many years on this and periodically do my reading and keep myself up to date on current evidence and progress. I have already demanded a number of blood tests due to the pregnancy - primarily FBC, iron and ferritin and of course folate and B12. I am a touch on the low side for all of them and am therefore taking action in a number of ways - including absorption - hence looking at what I am actually taking and specifically here whether I should be taking B12 in a different form. Unfortunately because my B12 levels are above the GP limits for deficincy I have a very hard time getting them to do any further testing or to even hear my concern. Hence, they are still trusting a test done over 10 years ago for IF that was negative and the fact that I can maintain 'adequate' levels through supplementation. I also have vitiligo so am well aware of the link with other autoimmune conditions and the inadequacy of IF testing.
My symptoms have been much the same for the last decade or two - primarily general fatigue varying degrees of 'fog'. This interacts with stress - of which I am regretably under quite a lot at the moment - and my fitness. There is only so much fighting I can do at the moment so I am looking at a number of routes to improve my digestion, reduce adrenal fatigue and support my liver and thyroid (both of which impact directly on digestion).
fbirder - given that I only take oral supplements (no injections) I took from the article that I may as well take CNCbl or a mix of MeCbl or AdoCbl. But, I now realise I can get HOCbl in sublingual form - maybe I should try that...? I am a bit behind with the supplement forms - the last time I looked into this and changed from CNCbl to MeCbl was a number of years ago.
I know that AdoCbl is relatively new in supplements so I was wondering whether anybody had any information as to its success (from what I have found it makes a difference in symptoms for some and not for others - which supports the idea that some need it and others can convert MeCbl).
Additionally, as with all science, this is only one paper so I expect there wil be some that disagree and think that taking the coenzyme forms is still more beneficial than CNCbl or HOCbl...
Does anybody have any more up to date information?
Where can I buy ampules of ADENOSYLCOBALAMIN B12?
B12 Supplement - Reaction ☹️.
Methylcobalamin Side-Effects?
Symptoms are worsening 
sublingual B12 pointless?
