Do you have neuro symptoms but normal serum B12?

Finally some recognition of the flaws in the serum B12 test. If you feel this is an issue for you please bring this alert to your doctors attention.

I am posting this here as I see so much B12 deficiency on this forum which is either undiagnosed or self-treated with sublinguals / sprays.


45 Replies

  • Thank you for that!

    You are so, so right.

    The website must be one of the "how bad can we make it?" category. In case it is very difficult for you to read, the actual news item is this:

    False normal B12 results and the risk of neurological damage.

    B12 assays may be vulnerable to interference resulting in normal values despite severe cobalamin deficiency. Where there is discordance between the clinical features of neuropathy – parasthesiae, loss of joint position sense, or megaloblastic anaemia and a “normal” B12 result, clinicians are advised to request storage of serum for further testing and are advised to treat the patient with B12 replacement therapy. Further testing may include repeat testing by an alternative B12 assay, holotranscobalamin assay, serum methylmalonicacid and measurement of intrinsic factor antibody. Treatment with B12 should not be delayed to avoid progression of neurological damage.

    References Carmel R, Argawal YP. 2012 NEJM 367:4 385-386 Hamilton MS, Blackmore S, Lee A. BMJ 2006:333 654-655 BJHaem. 2010 149 supp 1 abstract 54 Devalia V. BMJ 2006:333 385-386 For further information regarding methods affected see downloadable publications - Holotranscobalamin assay 2010 - go to members area- participant information - publications.

    (My emphases within the quote.)


  • I know, we need some success stories! When I eventually get off the Carbi and get my Graves into remission (sending positive vibes as I write) maybe I can be one of them? One thing's for sure, and I know it's specific to me, but I was ready for the scrap heap without my B12 jabs and folate.

    Meant to include in my post that the head of the PAS has asked for the wording of the above to be changed so that it includes any B12 symptoms, not just neuro ones. Reason being why should we have to wait for neuro damage to occur? Any updates on this I'll let you know.


  • Certainly hope you will be a success. :-)

    100% agree re waiting for neuro.

    I also note that, as I am sure you know, megaloblastic anaemia can be countered by iron deficiency or masked by folic acid supplementation. So having that as one of the cardinal signs is, in my opinion, wrong. It should be one of the "often happens" signs. Appropriate testing of iron levels should always be a part of the assessment of PA to try to avoid falling into that trap.

    It annoys me very much that folic acid is dished out in pregnancy without even a glance in the direction of B12.


  • Yep, as far as I'm concerned the words "vitamin" and "anaemia" need to be erased when talking about B12.

    "Vitamin" because, with supplements available in every supermarket and corner shop, we have somehow managed to trivialise the importance of these compounds in making our bodies function correctly. If it was called something like cobalamin malabsorption syndrome it might have a bit more gravitas!!!

    "Anaemia" for all the reasons you've said above regarding iron, but also because, very simply, you can have the condition without having megaloblastic anaemia. I didn't have anaemia, I had a low normal serum B12, yet I had all the symptoms, a raised MMA, and I responded to treatment. So something is very very wrong with how the medical profession understands and interprets this disease. Not to mention their inexplicable reluctance to dispense a non-toxic treatment that might just do the trick, instead of the myriad of other things they dish out, such as antidepressants and PPIs (I'd like to point out here that my doctor has been great, just in case he's reading ;-)).

    Folic acid is an interesting one, because I believe that in this country they hold back from adding it to things like bread because of B12 concerns, yet as you say they're not telling pregnant women to take B12 with their folic acid. And it might actually prevent some pre-eclampsyia if they did... but I can't remember where I read that study!

    Oh my gawd, you got me started - I need to go and do the dishes / cleaning / shopping.

  • Thanks Helvella and Hampster1 for all your time/research/links.

    Might like to follow this link up?

  • Can't get into this link?

  • Neither can I! Sorry, it was supposed to lead to this article:

    Do we need to reconsider the desirable blood level of Vitamin B12? by A David Smith and Helga Refsum.

    Hope you find it.

    Another link ( please work) to another paper from the Linus Pauling Institute: B12/

    This link deals with connection between adrenal fatigue and DNA methylation, very interesting

  • Not doing well at all...

    second one:

    Cross fingers.

  • Works OK this time.

  • Very interesting, I've bookmarked them all! My mother died of breast cancer when I was younger, I often wonder if she had undiagnosed PA, guess I'll never know. I have found other relatives on her side of the family who have B12 jabs and ATD...

  • maybe she was hampster1 (your mum: deficient in b12), I know my mum was and she was never treated, this makes me so sad, she developed 'alzheimer's disease' age 50, after this she was tested for B12 which came hugely BELOW normal range, they NEVER gave it to her!!! she died age 69, I know that if they gave it to her it would have alleviated the symptoms she had and if she was tested when she was first exhibiting mental symptoms and would she have been treated she would have probably ended up find with no alzheimer's :(

    very sad, the only reason I do not sue is that it would prove very difficult to get anywhere now that she's dead, but I still feel like doing it just to show them where they went wrong :(

  • And therein lies the reason why we try and look forward and raise awareness to prevent further tragedies like this. If these conversations help even just one person then its worth it, isn't it?

  • 'absolutely'

  • My late mother developed severe peripheral neuropathy resulting in muscle wasting in her legs meaning she couldn't walk very well. She was given pain relief and Vitamin B Co Strong tablets, that was the sum treatment. If only I had some knowledge about B12 back in the 90s. I'm just about to send off for copies of her medical files, I want to know more!

  • This must have happened to me. When my endocrinologist finally admitted that he did test my B12 levels back when he first saw me, and it was 197 (range 196-900), and that "could have possibly been a bit low, although people happily tick along at these low levels...". During those 6 years, I've had 2 children (with lots of folic acid, obviously) and worsening neurological symptoms with no sign of megoblastic anaemia, so B12 completely ruled out by the neurologist (the GP forgot to test for this initially!), and finally ended up supplementing myself (I thought that it couldn't do any harm to try!). Neurologist sent for MRI and electrical conduction tests at huge expense, to find 'nothing'. Strangely improved now, although some lasting sensory problems in my fingers and toes. I wonder how long I had been lacking in B12?!

  • You could have written the book on mis-diagnosis of B12 deficiency. Sorry, cobalamin malabsorption syndrome. :-)


  • I have a theory on Endo's, and it's this: they're so used to seeing low levels of B12, because pretty much all thyroid patients languish at the bottom of the range, that they've actually come to think of these low levels as "normal".

    As for your story, it's outrageous but depressingly typical. You're lucky to have responded to supplements as not everyone does.

  • Pretty well my story also- minus the children. Now OK, all 28 worsening neurological symptoms gone, but did it by DIY like you. B12 deficiency was ruled out though serum B12 167(180-800) but no megaloblastic anaemia so refused treatment. Was told "We have many people with levels like yours and they do not complain." , among other incredible responses to my pleading for treatment while showing my writhing muscles, telling of other symptoms, non-visible. Refused to read my log of increasing symptoms, dismissed unread as a sign of "health anxiety" with "if you go looking for symptoms you will find them."

  • Above was in response to ejh1 as well as for general consumption.

  • I wonder if the Care Quality Commission [CQC] is looking into this? HoHo!

  • Went to GP yesterday to be told that my B12 was fine at 359. ( I know it is not and since it was about 270 this time last year and I have been supplementing with Methylcobalamin at 1000 iu's, I may now up this to 2000 iu's until I get to 500 or so. At least it is going in the right direction, but think I will now get an Active B12 test done. Janet .

  • If you're having the Active B12 test you need to stop supplements about a month before (that's what St Thomas' told my Mother-in-Law anyway, when she phoned and asked). Or you could carry on with the supplements and up the dose, nostoneunturned has links on doing this. Methyl doesn't work best for everyone, I definitely respond more to Hydroxo. I think there's some complicated genetic answer as to why this is the case, and I've seen articles about this on the PAS forum, but it's way beyond my current level of understanding.

    H x

  • Hi Hamster1, Thank you for this information, always useful to know little things that could affect results. I think for the moment I will carry on with the Methylcobalamin and just up the dose. Janet.

  • I was talking to my GP's receptionist about that today. I'll print these off for my GP.

    I took the advice of the people in here and checked that my GP had no objection to me taking methylcobalamin - he didn't but also said that there was no need as my serum B12 result was "normal" - and have definitely seen some improvement over the last 6 weeks. I mentioned it to the endo who took the same view as my GP. Their lack of awareness is so frightening.

    I'm glad I found this site!

    B x

  • Hi This is well known, a FBC gives a better indication., However, Diabetes also has similar symptoms, autoimmune and hormonal, so this needs testing too, and annually.

    Best wishes,


  • Hi Jackie,

    Thank you, this website has definitely taught me to not be so myopic, as there are many medical conditions out there with similar symptoms and similar difficulties surrounding diagnosis and treatment.

    I realise that this blog is a bit of a B12 indulgence on my part, but in the interests of completeness, and very respectfully, I'd just like to slightly disagree with you. The FBC is not a great indication of a B12 deficiency, for the following reasons:

    - Haematological changes can be masked by a co-existing iron anaemia, or by someone taking folic acid without taking any B12

    - Haematological changes are considered to be a late marker of deficiency, and I'll quote from one of the articles posted by nostoneunturned above:

    "The proscription that cobalamin deficiency should not be diagnosed unless megaloblastic changes are found is akin to requiring jaundice to diagnose liver disease’ [1]. This statement by Carmel, one of the leaders in the vitamin B12 field, was made more than 10 years ago and yet many physicians and health authorities still insist on haematological changes before accepting a diagnosis of vitamin B12 (cobalamin) deficiency. It is not unusual that health authorities refuse prescriptions for vitamin B12 in patients with clinical signs of neuropathy because the patients have no haematological signs, and their plasma vitamin B12 levels are reported as ‘normal’. This situation is disconcerting in view of the long history of studies showing that neurological signs of deficiency may occur in patients who do not show anaemia [2]. Even in patients with clinical pernicious anaemia, up to 28% do not have anaemia and up to 33% have normal mean corpuscular volume [1]. How, then do we define which patients with clinical signs or symptoms should be treated and what is the desirable plasma vitamin B12 level below which treatment is required?"

    Full article here:


  • Hi Yes I do agree, I just meant it is better than the B12 blood test, but only as an indication.This is how a friend was diagnosed by my Endo, apart form seeing 3 others before her.Unfortunately no blood test is brilliant ,some less so than others.

    Best wishes,


  • Gosh your poor friend. I really thought the one thing doctors did get taught was the haematological changes, I guess even that is beyond some. You're right, there is no "gold standard" blood test, it would be so much easier if there was.

  • I do B-12 shots monthly and my Folate -Serum is 20.0 why so high?

  • Doesn't look that high to me, what's the range?

  • 5.2-20.0 my B-12 test was 450

  • I would say your B12 is still pretty low for someone who's on monthly injections. You really need to be up over 1000 at least for any healing to occur. Everyone is different. Are you still symptomatic? Have you thought about doing them more frequently?

    We have a very friendly Facebook group if you're interested:

    And lots of info on the PAS forum:


  • what do you mean by symptomatic? I was doing shot every 3 weeks for awhile maybe I should go back to that, thanks

  • I just mean do you have any symptoms?

  • I do have Perphrifial Neuropath that has been getting worse over the years, maybe I should do 1 shot every 2 weeks I don't think it would hurt.


  • I do them weekly, which is right for me at the moment. You should think about adding a B-Complex, because your other Bs can get out of balance, and just make sure your ferritin level is good. It may well be that you do need extra folate or iron, which might make a difference to the neuropathy. The red cell folate test is a better indicator of what's going on at cell level I believe.

    Most B-Complex's have 400mcg folic acid in them, but you'll probably need more if on more frequent injections, at least 800mcg? Folate can drop quite quickly once you're getting enough B12 so just try and monitor it. Some people need to stay on 5mg per day permanently.

    More info here:

    H x

  • Thanks for your help can I get B-Complex over the counter? Maybe that is why my Neuropathy has been getting worse because of my Folic & Iron is low?

  • Yes you can get a B-complex OTC, just make sure it contains all the B vitamins, I think there's 8 altogether.

    I use Pure Encapsulations B-Complex plus (from Amazon, not cheap but good):

    For a much cheaper high street equivalent Holland & Barrett do one called Complete B:

    Vitamin B6 can actually cause nerve damage if taken in excess, so just make sure whatever you take has no more than about 60mg B6 in it. Both of the above are fine (10 or 20mg).

    And definitely get your serum iron and ferritin checked if you can.

  • thanks I will you are just like a Doctor merry Xmas

  • Oh my gosh, not a doctor! Just had some great advice that worked for me and many others from the PAS.

  • I am doing 1000 MCG/ML injection one per month and I just had a blood test and it was 450 always on the low end maybe I should do them twice a month, you did say you did one shot per week?

    thanks Ross

  • Yes, I was having them 2 weekly but my GP left and new one will only give 3 monthly. So I'm now doing my own and have gone to weekly as symptoms were actually returning sooner than 2 weekly. Feel extremely well. My whole (boring!) story is here: pernicious-anaemia-society....

  • I had the Schilling test done twice in the past 20 years I think you hit on something with my Folic acid and Iron and B-Complex because for me to do 1 shot a month and then my blood test came back 450 just seems low?

  • I had Shillings Test done 20 years ago and then I had a test at Mayo Clinic in 2013 to confirm it and I do have Pernicious Anmeia

  • Yes you don't know what the body is doing.

    Either it's using it up or it's not taking it on board?

    Everyone with a aultoimmune problem has low vit d.

    Just it's not a reutean test

    and it costs. My GP refused when I asked him. The consultant I saw did test and found I was low. Told me to go to holland and Barrett.

    He said I was also mad. They have to dig the knife in.

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