What exactly is Functional B12 Deficiency?

I was told I had B12 deficiency(196) and had 6 loading injections then 1 every 3 months. By the 2nd of these 3-monthly injections, I did not feel any benefit and had got a lot worse in terms of symptoms. Blood tests 6 weeks after the 2nd injection, and told MMA level was raised (351) and that because plasma B12 was over 2000, confirmed "functional B12 deficiency"- although I thought over 2000 would be expected after injections started : it's confusing to me.

Since then have been reloading: the first 5 did nothing, so improvements, even minor ones, delayed. I have now had about 14 loading injections altogether (2 a week), feeling slightly better but some of the nurses are getting reluctant to give me any more before seeing GP again, although she said no need to see her again, and to go on to monthly injections when no further improvement. This is clearly very new to them. I'm seeing Dr on Thursday pm, for a certificate, but also I'm guessing to have a review of new programme- don't even know what to ask for/ rule out any more.

My cousin has very recently been told she is B12 deficient too. Don't know her details yet.

I've been trying to sort out what exactly is wrong with me for almost 2 years now. Hip bursitis, lower back pain, diarrhea, dizziness, cognitive difficulties, mood swings, need for sleep, need for solitude, fogs, sensory overload, muscle weakness in limbs,trouble fighting off infections and hair loss (at least that has stopped currently) all still there but improved. Still problematic getting all these recognised as related symptoms- especially by gastroenterologists, who have not done any tests because I don't have a stomach ache, and /or they believe I have IBS. Give me strength!

I've had lots of blood tests, ferritin and folic acid being treated as both within range but low. All else on FBCs etc seems very mid-range normal as far as I can see. No liver problems. Can anyone help?

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  • Functional B12 deficiency is B12 deficiency at the cell level although serum levels are high.

    Basically something goes wrong with the mechanisms that transport the B12 from your blood and transfers it to the cells where it is needed. It is generally an autoimmune response triggered by high levels of B12 in your blood, as your body responds to the high levels in serum by shutting down the transportation. I don't know if it is linked to any other similar responses and I'm sure there must be some as it would make sense for the body to respond to high levels of substances that could cause damage by shutting them down.

    B12 doesn't have any known toxicities so it is a response that doesn't make much sense and just leaves you without B12 at the cell level. In theory the response would stop if levels dropped below the point at which the response kicks in but this could take a very long time, leaving you very ill for a very long time.

    I visualise it as being like a dam built to stop flooding but which has the undesired effect of actually causing a drought. The only way to get water on the other side is having it trickle over the top - which means keeping the levels of water very, very high so just enough trickles over the top.

    The fact that your MMA was really high was the demonstration that your cells weren't getting enough B12. MMA is a waste product that builds up if your cells don't have enough B12.

    Sometimes functional deficiency is used to cover cases where serum B12 is in the grey range but people are highly symptomatic but strictly speaking functional deficiency involves high levels of B12 that are above the normal range. The fact that some people are lower half of normal range but highly symptomatic is more to do with the fact that people vary significantly in the amounts of B12 they need to function properly.

  • Note: functional B12 deficiency can arise without artificial supplementation (B12 shots) in some conditions which stop B12 a person who is able to absorb B12 normally being cleared from the blood eg by the kidnesy, with the consequence that B12 levels in the blood get higher and higher. The patient will present with all the symptoms of a B12 deficiency but the B12 serum level is abnormally high.

  • That's a fantastic explanation.... thanks Gambit62

  • Thanks, Gambit, this is really useful to me.

    Theory about dropping to a point below response level sounds scarey to me since I was very ill already and had been for a year at least when diagnosed as deficient at 196 (range stated at 197 upward -so only just) but MMA not measured at this stage.

    Not sure I can go there again.

    Gambit, in your experience, is it possible to get the high levels needed recognised by and supplied on the NHS, or am I wasting very precious energy on this ? Do ALL people with "functional B12 deficiency" diagnosis end up self-injecting?

    Can B12 be measured, for comparison, at cell level at all?

  • a) personal experience - gave up on GP but then started from 40+ years of low expectations. however, there is this article from afew years back so it obviously is possible


    although I supplement not all of that is by injection - use nasal sprays as the mainstay of my supplementation - and some adenosyl sub-linguals. I could probably get away without injections at all - though they are quite a convenient way of starting the day.

    b) As far as I know there is no general way of measuring directly what is happening at the cell level. There are a couple of tests that look at build up of waste products that can indicate if there is a deficiency at the cellular level but I'm personally not entirely convinced that this always works whilst you are supplementing and I've never personally gone down that route. There is a test for TCII antibodies but I've only heard of it being done in relation to specific studies and no idea how much it would cost or where you would get it from. TCII antibodies have been identified with functional deficiency but I've no idea if they are the only thing that is linked to functional deficiency

    Basically there doesn't seem to have been much research on functional deficiency or the incidence of functional deficiency in people receiving treatment for B12 - was a study in denmark in several decades ago but haven't been able to track down any paper directly coming out of the study - mentioned in this paper - reference 65


    totally with you on not being able to go there again. Think it is a strategy for some people if the clear B12 quickly from their blood stream and would also depend on what the trigger point is. There have certainly been posts from people who find that 0.5mg doses of hydroxo work better for them than 1mg

  • Luckily for me, I have had the benefit of your advice and a GP willing to listen and learn about functional B12 deficiency from people who have had to live with this condition. She is also not afraid to use her eyes- recognising that, within a month, there had been visible improvements. Have given her the notes from your advice and Foggyme's - she's bright and curious and has 2 patients with this problem. Your help is reaching so many more people than you know, and may one day restore your faith in (some) doctors.

    Have a peachy weekend, Gambit62

  • Hi Cherylclaire.

    What Gambit said πŸ˜€ (brilliant explanation) and...

    How to deal with your GP appointment....

    Based on Gambit's explanation looks like there are two possible options:

    1. Either keep your B12 levels very high so that some trickles over the top of the dam (to follow Gambits analogy)

    2. Stop B12 until your levels drop below the level where this response takes place (again, as Gambit points out, this could take a very long time).

    As I see it (and this is only me thinking), there's no knowing how long option two will take and, more importantly, nobody can say for sure what (if any) damage is being done in the meantime (due to the potentially ongoing state of deficency at a cell level).

    Think this is what they call being stuck between a rock and a hard place πŸ˜–.

    Turner and Talbot (2009) wrote a paper on the subject of functional B12 deficiency, their conclusion being that patients with functional deficiency may respond to high doses of B12.

    As for the nurses....well, they obviously haven't heard of the neurological regime for B12 deficiency. I should point them back in the direction of the GP who authorised your frequent injection. And better still, also point them to the PAS website - it has a section for medical professionals - they might be able to educate themselves πŸ˜€.

    The good news is that you are feeling slightly better....so some B12 must be getting through to the the cells (albeit not quit enough yet).

    Even in the absence of functional B12 deficency, recovery can take some time, especially when the deficiency has been present for some time prior to treatment.

    So don't lose heart...at least now you now know what is happening to you and the slight improvement gives rise to the hope that this will continue.

    Good luck and let us know how you get on πŸ‘

  • Foggyme, what do you think?

    Will NHS be likely to supply high doses of B12 indefinitely?

    Would they be more likely to agree if some further proof supplied of deficiency at cell level....is that even something that can be tested for?

    Anything else you could suggest in terms of testing that might improve chances of ongoing treatment?

    I am a lot better but STILL feel like I had a dogbrain transplant.

  • The only way of testing this is to keep an eye on your MMA and homocysteine levels. There are no direct tests of B12 deficiency at cell level.

  • Hi Cherylclaire.

    The first thing to say is that you already have proof that your have functional B12 deficiency (the high serum B12 together with the high MMA).

    There are other tests that can be done but as far as I am aware, these are usually only done for research purposes (can't recall what they are and don't have time, right now, to look them up - TC11 antibodies, and other things, I think) but will do so if it becomes important to you).

    How long will the NHS provide frequent (high) doses of B12 - theoretically, the neurological regime of every other day until no further improvement could be followed for many months - but many struggle to get this and there does come a point (for some) where no further improvement takes place.

    So....how to deal with this...here's some thoughts that might help..but they're only my thoughts..

    I think the key here is getting your symptoms under control - the right amount of B12 is going to be the right amount of B12 to get you as well as possible and keep you as well as possible. And it might take some time to work that out.

    Getting treatment from your GP will, I think, rest on providing as much evidence as possible for the B12 regime you need to keep you well.

    Some things that might help with getting treatment from your GP:

    Keep a symptom log so that you can track and monitor your symptoms, in particular in relation to when you have your jabs (perhaps a spreadsheet where you record all your symptoms, on a daily basis (at least to start with), giving a severity score between 1 and 10 - noting down when you have your jabs. A pattern should emerge and you should then be able to start predicting how often you need B12 to keep your symptoms at bay. You will eventually be able to adjust the frequency of injections needed (perhaps longer between jabs) and will be able to tell what the right frequency is for you - and this may change over time. More importantly, your GP will have 'evidence' about the efficacy of your treatment (or not). Theoretically, it should be easier to get him to agree to an individual B12 regime that suits you, rather than a regime imposed by misunderstanding or guidelines that do not suit your individual needs. (I understand that this worked very well for fbirder.)

    Start an 'evidence' file for your GP (more difficult to argue with evidence).

    Get hold of hard copy evidence stating that you have a functional deficiency (this might be a copy of your blood results and / or a letter from a conultant saying that you have this).

    Print off anything you can find on the PAS website about functional deficiency. Likewise from b12deficieny.info (not sure how much there is, but worth a look). Also try b12d.org.

    Search the Internet for anything you can find about functional deficiency (bit only use sources that are underpinned by a medical research based approach - avoid woo woo sites).

    If you PM me an email address, I'll send you a copy of the Turner and Talbot paper - hard research based evidence that high dose treatment is the way to go (at least when this research was done, and there hasn't been a lot published since - though new research may be in progress - a good question for the PAS conference, I think, and looking forward to new PAS science blog going live inDecember). Your GP will not be able to dismiss this.

    Once you have out your reasearh file together, it might be a good idea to make a double appointment with your GP to go and discuss functional deficiency (you will probably have to educate him πŸ˜–) and ask if you can develop a care plan together (with agreed frequencies for B12 injections - and treatment review plans).

    If you can get your GP on board early and put a plan in place think it'll reduce the stress on you and enable you to focus on recovery - rather than contentious and potentially difficulty GP consultations. Ask him to brief any surgery nurses - for the same reasons.

    Also might be a good idea to take someone with you as a witness - a witness sometimes turns a GP into a more approachable and amenable creature.

    The only other thing I can suggest - Guys and St Thomas hospital in London have a specialised interest in functional B12 deficiency - very well worth asking your GP to make enquiries and refer you there for treatment. This should not be a problem as you have a proven functional deficiency. Interestingly, they would be able to perform the additional tests I spoke about earlier (if they thought it necessary).

    Anyway, these are just some thoughts that might (or might not πŸ˜€) help.

    Be really interested to hear how you get on.

    Take care πŸ‘

  • Foggyme, can't thank you enough, so here's the update and it's VERY good news...

    Went to the Dr last night and firstly, she was delighted to tell me she could see how much I had improved in a month. She is going to send me to St. Thomas' neurology dept. next because of my cognitive, sensory and memory problems, told me this was not her area of expertise and that she had another patient who also has functional B12 deficiency with neurological symptoms, so seemed quite happy to accept my notes from all the advice given to me by you and Gambit. Quite a lot to take in but did highlight areas- she is going to look into who might be interested specialists at Guys & St Thos. Also said to carry on loading as it was clearly working, and that she would speak to the nurses about this! So on the strength of that, I booked one up for tonight! (Bet THIS one's going to kill!)

    Two last things:

    I will need surgery soon on torn rotator cuff- anything I need to know about specific anaesthetics & effects on B12?

    "If you PM me an e-mail address" : I most certainly would if I knew what it meant and how to do it!

  • Wow Cherylclaire...this is just fantastic news πŸ˜€πŸ˜€πŸ˜€.

    A doctors who listened, recognises functional deficiency, orders frequent B12, and refers you to the right specialist...my eyebrows are on the ceiling and my jaw is hitting the floor.

    You must have worked really hard to make this happen...so very well done πŸ˜€.

    Anaesthetic - nitrous oxide, a gas sometimes used in anaesthetics, deactivates all B12 in the body. There are other things that can be used so there is no need for you to have this. Tell,your anaesthetist you have B12 deficency and you do not want to be given any (some are aware that it's contraindicated, some are not). Also tell the nurse (in fact tell everybody involved) who does your pre-op check. I write it 'B12 Deficiency- Do Do Not Give nitrous Oxide' in block letters on the top of the consent form and also ask for a red allergy label to be attached to my wrist.

    How to PM: There's an icon with your user name in the top toolbar on the left hand side. Click on this and a drop down menus will appear. Click the message tab and the messages page will load. Click the green 'compose' tab (top right of that page' and a new message 'thingy' (for want of a better word πŸ˜€) will appear. Type in the name of,the person you want to mail (in this case Foggyme) and click on the Foggyme tab - that name will be inserted in the message address bar. Type away and press send. Hey presto - message done.

    Will send paper pronto.

    Lots of people here ask questions about functional deficiency...but not a lot is known so...anything at all that your discover from the London end....would be great if you could post the information. And updates....'cause we'll all want to know how you're doing.

    Oh this has really made my weekend...but I bet not as much as it's made yours πŸ˜„.

    Well done, well done, well done πŸ˜€.

    P.s. Think your GP deserves two gold stars (and that's a first).

  • Glad I caught you before leaving the library - I've got 13 minutes' use left so I'll make it quick. Trust my Dr and really like her. Yes, this has been a long, frustrating journey for us both but she never stopped trying, and I went along with (almost) everything she suggested even if only to eliminate it. That is why she will also accept that little is known and much can be learnt from those who have had to live it.

    Too dog-brained right now to concentrate on instructions on how to PM but will, believe me. Of course I will let you know: none of this would even happen without you - and a Dr who is willing to stick by you, of course.

    "Lovely job, tell yer mother" as my old carpentry apprentice-master used to say!

  • Yay to that πŸ˜€. PM whenever...no rush, will keep an eye out for incoming.

    Dog-brained...know it well...hope you perk up soon πŸ˜€

  • I've just noticed that the NHS web page on B12 and folate deficiency anaemia includes a section on Functional B12 Deficiency - nhs.uk/Conditions/Anaemia-v...

    Some people can experience problems related to a vitamin B12 deficiency, despite appearing to have normal levels of vitamin B12 in their blood.

    This can occur due to a problem known as functional vitamin B12 deficiency – where there's a problem with the proteins that help transport vitamin B12 between cells. This results in neurological complications involving the spinal cord.

  • Thanks for that, but this is confusing to me, fbirder, because the first B12 blood test I had (Feb 2016) DID show a deficiency- and this was why I was being injected and monitored originally: it was only because I was getting worse not better once on 3-monthly injections that MMA was tested and found to be raised (although plasma B12 was over 2000) - this was in October.

    Anything I have found, and there isn't much, talks about functional B12 deficiency with NORMAL B12 blood levels as does the quote above. Nothing I have found yet gives GPs advice about on-going treatment, which could present problems.

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