B12 problems

Hi there ,

Please can someone offer me some advice as to what to do ?

I saw my gastroenterologist yesterday and she said that my B12 was very high and this is the reason I can barely eat and I am exhausted all the time as it's the same symptoms of low thyroid . Please has anyone ever heard of this ?

I am dizzy as well all the time - the doctor wants to put me on to stomach acid tablets for six weeks which I'm scared about as I know that stomach tablets are not good for the thyroid .

Many thanks for taking the time to read this 😀

25 Replies

  • I am horrified to hear that your gastro has told you this. I can assure you it is utter rubbish. B12 is not known to be toxic when high, indeed very high doses are given to treat cyanide poisoning.

    What does he/she call 'high' in any case? Do you have any results you can share with us? Also, do you have any recent thyroid test results?

    I assume by 'stomach' tablets, you mean a PPI or similar. Why does your gastro want to prescribe these for you?

  • Hi Hillwoman ,

    Thank you so much for your kind reply . My results are as follows :

    Nov : T4 17.1 range 12-22

    T3. 8.5. Range 3.1-6.8

    TSH raised 0.02 range 0.27-4.2

    Folate 9.7 range 4.6-18.7

    Iron profile improving

    Ferritin 401

    The gastro is happy I am now nine stone thirteen five foot six as last year when I saw her I was under nine stone . She wants me to get camera test done but I won't do it as I teach singing and they were rough several years ago .

    I'm dizzy all the time tired and can hardly eat migraine after another . I don't think she honestly cared as long as I have put on weight . I was feeling great in the summer . My endo gave me b1 b5 & b12 as he said I needed them . He's now off sick and saw another one who said thyroid is so easy to manage and some people are prone to dizziness .

    I will have to wait to January to see my other endo as I don't hold out much faith in this one as he didn't like me using T3 either .

    Thank you .

  • Your FT3 is actually above range. What is your current dose of thyroid medication?

    Do you have the serum B12 result that your doc thinks is high?

    Do you have the reference range for the ferritin? It looks very high.

  • I don't have the range for the ferretin no sorry though doctor did say it was high though it's going down . I was very anaemic and my consultant gave me an iron infusion about eight months ago .

    I am taking 75 my levothyroxine and 15 mg iliothyronine . I got them tested again on Tuesday though didn't fast unfortunately .

    Thank you

  • That might explain the ferritin result!

    As for serum B12 (cobalamin), different countries vary a lot in what they consider to be a useful reference range. As you've been supplementing with it on medical advice, I'm not sure why your doc should suddenly take fright.

    Do post again when you get your new thyroid test results.

  • Was your blood taken soon after taking your thyroid meds?

  • Hi Human bean ,

    Thank you for getting back to me . I took my thyroid tabs about nine in the morn and bloods were done at around one .

    Thank you :)

  • Both your Free T4 and your Free T3 would have been lower if you had skipped your meds before testing.

    The usual advice given on here is that T4 (Levo) should not be taken in the 24 hours prior to testing.

    T3 should not be taken for 12 hours before testing.

    I'm not sure what people are supposed to do if they take both.

  • As far as I'm aware B12 is excreted out of our body if we take too much. I've looked at your second post and see that it is just over 1,000. The recommendation, as I believe, that it is mre beneficial to have a B12 around 1,000.

    What were your symptoms you complained about to the GP (if you don't mind putting them on the forum). Why is he suggestion stomach-acid tablets?

    I've looked at your past post and there was no TSH although your FT4 and FT3 seem fine.

    Did you fast before your blood test and was it at the earliest possible and did you allow 24 hours between your last dose and the test and take it afterwards?

  • Hi Shaws,

    Thank you for getting back to me I really appreciate it . I just feel dizzy sick tired all the time and can hardly eat anything and constant migraines .

    I have stopped b12 three weeks now and take only thyroid meds . The gastro suggested stomach tabs such as Lanzoprazole for six weeks to help .

    Thank you

  • But to help what, angie? You're not giving us enough information to be able to help you.

    Lanzoprazole will lower your B12, is that what he's thinking? But it doesn't matter that it's that high. And, taking lanzoprazole will probably affect the absorption of all your other nutrients and your thyroid hormones, because it lowers stomach acid. And yours is probably already low!

    And I think your doctor is a little confused about B12. As far as I know, it isn't high B12 - and yours isn't that high, anyway - that mimics thyroid symptoms, it's low B12. So, your thyroid symptoms are actually your thyroid symptoms.

    Your TSH is suppressed, not raised. Raised would be over 1. But, your FT3 looks to me like you took your dose before the test. What time was the test done? And, had you eaten or taken your T3?

  • Hi Grey goose ,

    Thank you for getting back to me as always appreciate it any advice .

    I think she meant I would be able to eat better but I did say to her about the stomach acid and she said a course of six weeks will make no difference or harm.

    I got the thyroid tests that I posted done in November early monrning and I definetly didn't eat anything . As for the other thyroid tests I haven't had the results yet sorry .

    Thank you .

  • If six weeks won't make enough difference to do any harm, then it won't do any good, either. I cannot imagine how she thinks that reducing your stomach acid will help you eat better. There's just no logic in that. You won't be able to digest as well as you do now - and apparently it's not exactly brilliant, now - and leave a load of fermenting food bunging up your stomach, leaving little room for anything else. I think she just wants to prescribe PPIs because she gets extra funding for them!

    You still don't say if you took your T3 before the test. Or did you leave the recommended 12 hours?

  • I didn't greygoose fast 12 hours sorry as I knew about T4 but not T3 and I didn't think they would test it .

    I did say to the endo I have eaten n took tabs though he said it didn't matter so I would imagine results will this time be higher .

    Should I not take stomach tabs ? I have been taking gaviscon and she prescribed anti sickness tablets though I haven't taken them yet .

    Thank you :)

  • No, endos have no idea that it matters! But, that explains why your FT3 is so high. And, why your TSH is so low - you must have had the test quite late in the day. So, those labs don't really reflect your thyroid status.

    Before taking the Lanzoprazole, I think you should check your stomach acid :


    There's a do-it-yourself test on that site. And, if your stomach acid is low, it really wouldn't be a good idea to take the Lanzoprazole. Symptoms of low stomach acid, are the same as high stomach acid.

    If you're feeling nauseous, that could be an indication of low stomach acid. It would be better to raise your stomach acid, rather than take drugs for it. :)

  • The Lanzoprazole will deplete your B12, as do many other medications.

    It would be more useful if your gastroenterologist tested Intrinsic factor to establish whether you have 'leaky gut' or damaged microvilli that make it more difficult to absorb B12, as you are at higher risk of PA with Hashi'moto's and problems with the stomach.

    Once you start supplementing with B12, levels in the blood will rise regardless of whether it is absorbed by the tissues. This is why, if you have symptoms such as dizziness, loss of balance, severe fatigue, etc. and suspect you might be deficient, it is recommended you do not supplement before seeing your GP.

  • Hi Shaws ,

    That is very interesting to know about low stomach acid . My mum has pernicious anaemia though not thyroid problems so my heart goes out to you as I know how tired it can make you feel .

    My gastro wasn't interested in anything other than the camera test which I refused as was very sick after that several years ago as they gave me too strong of an anaesthetic for my weight .

    Do you think I should go back on the b22 b5 b6 . She said not to stop gluten as I was fine even tho I feel sick n stomach swollen . She was more chuffed I was near ten stone not how I'm feeling . My moods are terrible one minute happy then v down teary for no reason . The brain fogs not good either I could b fine one day and the next totally burning up dizzy n dopey it's strange . I'm thinking I need to cut out sugar n coffee as I crave those .

    Thank you .

  • A history of PA in the family, as well as Hashimoto's means you are higher risk of PA and the symptoms often overlap. Dizziness and brain fog could be neurological and should not be ignored - lots of information on the PA site here,

    I'd also recommend Dr. Datis Kharrazian's books, "Why Do I Still Have Thyroid Symptoms?" and "Why Isn't My Brain Working?", in which he advises following a gluten free diet to help heal 'leaky gut', the root cause of autoimmune disease.

  • I have pernicious anaemia and hypothyroidism. I have quarterly B12 injections. However re your stomach we, being hypothyroid, have low stomach acid (because everything slows down) and need to treat stomach acid to enable our body to process food inour stomach. The fact that low/high symptoms are so similar doctors prescribe what your doctor has.

    I think it is very rare to have high stomach acid and hypothyroidism. The fact that symptoms of high/low are identical doctors prescribe what yours is doing/has done. It is a condition called Hypochlorhydria,



  • Having high levels of vitamin B12 or taking high doses of vitamin B12 are discussed on this link :


    As the link shows, the reality is that B12 is not dangerous at all. But lots of doctors get twitchy about high levels, goodness knows why!

  • Thank you human bean for that information about b12 maybe I should start taking it again !

    I didn't think about fasting sorry and I didn't realise it was 12 hours I will do that next time . I also because I was so tired have taken extra T3 which is possibly why it's raised though endo said I could do it the odd time but because he has been sick and not seen him since August I think I have increased it to 20mg four times over this last few months.

    Thank you

  • You should be investigated to confirm you don't have PA. So I would stay off the B12 supplements and then be investigated to confirm you don't have it. Only once it is established you don't have a problem then start supplementing.

    There is another test you can do which is an active B12 at St Thomas hospital which is better than a blood serum test. I know private providers also do the test but I can't remember how long you need to be of supplements for it to give a useful result. (Go on the PA forum on health unlocked and ask them about testing for PA indicating you were supplementing B12.)

    Also while it's well known on this forum, even the NICE guidelines clearly state that someone who has started to supplement B12 should NOT be tested again for B12 deficiency using a "normal" test as the results are unreliable. So your high result just tells the doctor you have taken supplements in the past few months nothing else.

    If you weren't supplementing it would indicate a possible liver, kidney or blood problem. I think the reason doctors panic is that they think it can hide blood problems, and if you have or had iron deficiency anaemia one way of confirming the diagnosis is the smaller size of your red blood cells. However excess or deficiencies in B12 hides this. In reality the labs should do an iron panel to confirm a diagnosis of iron deficiency anaemia where they aren't sure but the NHS likes to save money...

  • Hi blue bug ,

    Thank you for your kind reply . My mum has PA I'm hoping that it's not that which I have had all these years and doctors thought it was thyroid . I am going to get zinc as I have heard it is good and apple cider vinegar see if that helps and eliminate most dairy from my diet see if that helps . I don't mind feeling sick it's the dizziness that throws me and the brain fog .

    Thank you I appreciate all your advice :)

  • For some people high levels of B12 in serum can cause an auto-immune response that effectively shuts down the mechanism that transports B12 to cells leaving you with a functional deficiency - lots in your blood but very little/none available at the cell level where it is really needed - the most effective treatment for this is more B12 to keep the levels really really high so enough gets through to cells.

    Having supplemented with B12 you would have to stop for at least 3 months - possibly 6 but no guarantee even that that all of the supplemented B12 would have left your system - before serum B12 and/or active B12 test would give a proper result. The test for PA as opposed to B12 deficiency is IFA - looking for the specific antibody that is involved. you would need to stop supplementing for about 10 days for this test.

    There are some test that could clarify if you have a functional B12 deficiency - looking at a chemicals that build up if you don't have enough B12 at the cell level for cells to recycle them into usable building blocks - namely MMA and homocysteine. However, I'm not, personally, totally convinced that these always work with a functional deficiency, though in theory levels are very sensitive to how much B12 is available at the cell level.

    If your mother suffers from extreme tiredness whilst being treated for B12 deficiency then that would imply that she is actually being undertreated - which is unfortunately extremely common.

    Lots of information on the PASOC forum


  • Hi Gambit 62 ,

    Thank you so much for your kind reply . I am off B12 three weeks now though still take the vitamin b1 I feel worse not being on it . it's so confusing as to know what to do for the best . I have cut down my work to three days a week but it still works out twelve hour days by the time I get home. I am trying to do my degree as well and teach singing so exhausted brain fog at times is really bad . I'm cutting out diffferent foods from today to see if that helps and start taking apple cider vinegar .

    Thank you :)

You may also like...