Hi all I don't know what to think anymore , I've just read on a site written by a Dr for people diagnosed with B12 deficiency Well he advises that sublingual tabs b12 are pointless as the B12 molecule is too big to be absorbed sublingualy so there is little difference between sublingual and just regular oral tablets as both are absorbed by the gut The other issue he mentions is that if you have pernicious anaemia no amount of oral B12 can be absorbed as you have no intrinsic factor He also states that in a healthy individual with normal intrinsic factor can only absorb a maximum of10mcg even if the dose is 500mcg so any larger doses are pointless So having ordered high dose sublingual b12 tabs I'm going to take them any way but I've also ordered a nasal spray Hey its a nightmare out there so much information ! It's just so confusing Mully

9 Replies

  • The use of oral B12 even in those without intrinsic factor is based on the idea that with a large enough dose some gets through the gut by diffusion.

    The very large doses are needed to ensure that at least some gets through. Sure, the amount carried due to "proper" functioning of the system limits absorption to something like 10 micrograms. Not sure if there is an upper limit on diffusion in the same way.

    Please don't take this as endorsement of oral B12 for Pernicious Anaemia sufferers because I am not convinced it can reliably deliver the required amount.

    Do you have intrinsic factor in your nose? :-) :-) :-)

  • Lol...I agree helvella...why take the risk when there is so much at stake...swopping to jabs after the event (the fail to absorb event) s'not much use if the nerves (neurologies) have been failed by the experiment.

    Even, I would say, if this happened to only one person.


  • For oral to be acceptable you'd need a reliable way of knowing that you really are absorbing sufficient - and with a big enough margin for you to get an injection if you are not.

    I can't see that coming any time soon.

  • Hi Mully

    I was told that when originally diagnosed by my GP who said no matter what we take orally it won't help!

    I just want to feel human again, good luck all 😉

  • I don't fully understand the science of sublingual absorption, but I can say for sure the spray helped me cope between injections. I also use it as a top up if I'm under stress for any reason. I'm not sure it would provide all the B12 I need, but it does help a lot.

  • Unfortunately there seems to be little research on the comparison of various routes of administration in people with PA.

    One patient case study - a child with low B12 after intestinal surgery treated with sublinguals

    The site you link to says...

    I finally confirmed through a couple of books and online references that the B12 moelcule (sic) is indeed too large to be absorbed in the mouth.

    And, annoyingly, doesn't list those references.

    The only study he references was performed on 30 subjects - more than half of whom were vegetarians and only two of whom had antibodies that may indicate PA.

    However, my personal experience is that the only thing that helps is jabs. But lots of people say they benefit from sprays, lozenges or skin patches.

  • Hi, Thank you for the replies I really am on my own with this (Dr has dismissed it completely, and will not enter into any further conversation!) As the private blood test came back at 134 and was repeated by the GP and was 211 I sent him a full and detailed letter raising all the points given in the pernicious anaemia website I can't help but feel frustrated as when I was diagnosed with MS it was 3 mths after having a baby and I had severe anaemia for which I was prescribed Iron , but it was atypical as all the scarring lesions were in the spine, plus I developed DVT's and was also diagnosed with antiphospholipid syndrome despite never having a positive blood test, I remember a particular call from my then GP 12yrs ago telling me that the lab had called to say my blood cells were horribly large and mis shaped again I was prescribed Iron The only relief I have had recently ( and it was dramatic) was when i was diagnosed as having a folic acid deficiency and after 3mths of tablets I could feel my legs again, I have written all the above to the GP and he refuses to even consider sending me for a second opinion I know I shouldn't take anything as it will mess up any further tests but have started taking stuff out of desperation just hoping to feel a bit better Lost the will to fight him

    I don't believe I have MS or antiphospholipid syndrome I've suffered with severe anaemia all my life although now apparently I am not Anaemic so they will not give me treatment

    oh plus 14 yrs ago after a massive bleed I received a blood transfusion it was the healthiest I have ever felt in my life Sorry for such a long post thanks everyone for your help

  • It sounds like you need B12 methocobalamin injections. If you decide to self inject you need the first one done in a medical setting in case of a rare adverse reaction.

    I feel for you. It sounds as if you need a new competent doctor.

  • Purely anecdotal, but I find that the sublinguals have barely, if any effect. I self-inject and find that a lot better. The tablets are cheaper, but for me they feel a bit pointless

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