b12 ranges

Hi I have just had my lab results and my b12 is 151 my endo and gp say that is ok but the references they work of are ( 145--975 ) I have graves and have just had to increase my carbimazole from 10mil to 15 mil as my T4 was raised again from 13.2 now 17.7 I knew it had as I was very shaky and anxious ,but my concern at the moment is my b12 even though I am starting to feel a little better since increasing my carbimazole I am still feeling tired and have awful brain fog my memory is really bad , I questioned my gp about why my B12 was so low but he and my endo say they are within range any advise please would be helpful

20 Replies

  • Just take b12, it is unlikely to hurt, very hard to take too much

  • Hello frian,

    Your B12 is too low as optimal levels are in excess of 500.

    You may find this link leading to an old previous post interesting.



  • When will the medical profession wake up to the seriousness of B12 Deficiency ? You are already suffering with Graves and need all the support possible. Only 20% of the result of your B12 test is available to be transported into the cells - where it is needed - so that makes your result even worse. The link below will tell you all you need to know about B12 and more....


    I think you also need more thorough testing as to why your B12 is so low. Additional testing required is detailed in the above link. Could it be that you have Pernicious Anaemia ? - so testing for anti-bodies of Intrinsic Factor and Parietal Cells is vital. You have one auto-immune condition - so you could well have another.

    If you start supplementing any further testing for B12 will be negated - but I also think it is very important that you have treatment sooner rather than later. I would suggest 5000mcg of Jarrow Methycobalamin - kept under the tongue until they have dissolved. There are also sprays. Ensure you also take a good B Complex to keep all the B's in balance.

    The link Flower posted is also great - my oh my how we miss Hampster and her knowledge.....

    Do hope you are soon feeling stronger....

  • I absolutely agree with Marz. This is so important. The damage that can be done by low B12 is unbelievable. And it is irreversable if left too long. When my B12 was at 350, I was losing the use of my right arm, and was having trouble holding my head up. And my doctor said my result was perfect!!! They just have no idea. I'm back to normal now, after supplementing for a year.

    So, please do take this seriously, and get tested for Pernicious Anemia, won't you. :)

  • Hi gregoose,

    I am just wondering what do you exactly mean by saying "I'm back to normal now, after supplementing for a year." Did it take you that long to recover from a b12 deficiency ?

    My b12 was 117 and I started taking 500mcg methylcobalmine injections last Saturday.I have taken 3 injections so far..........I was suppose to take one today as I take them on alternate days but my periods started this morning and I am just wondering what to do now?

    Is it OK to take b12 injections when on periods or should i take mcb tablets instead?

    It's strange that I had my periods early this month.I was suppose to have them on 18th.But thank god there was no pain this time.

  • I meant that I have no more pain in my arm, no trouble lifting it above my head, I can carry things, and use my arm normally, and my head now sits solidly on top of my neck! No more wobbling around!

    It was a slow process, recovering, but some things got immediatley better. I think, actually, I've been B12 deficient most of my life. It was tested about fifteen years ago, and found to be low, but nobody said anything, or did anything about it. And I didn't know in those days.

    I know of no reason why you shouldn't have an injection of B12 during your period, but then I've never inquired into that aspect. It could be that your period was easier this time because of your thyroid treatment. :)

  • My B12 result was very similar and the gp wouldn't treat it either. I believe it's quite common with misbehaving thyroids that we don't absorb it well from our diets, therefore oral supplements are ineffective. I use a sublingual spray called Boost B12, spray it under your tongue and hold it there for a few seconds, it goes straight into the bloodstream and you'll feel the difference very quickly.

  • Posts here suggest B12 should be at the top of the range.Google Dr.Chandy B12 and have a look at the sites that appear. He was a speaker at the last TPA conference.

  • Hello my b12 was even lower and still doctor said it was fine , even though it clearly said on blood test that it was abnormal . In the end I mistrust my doctor so much that sometimes even when I need to see him I just hold off going to surgery as all my trust has gone .on one hand they say we must go by blood results then he says we ignore thst results . It's all crazy and I don't understand why ? All I can say is supplement yourself do your research and as far as possible self medicate and look after your own health . Sorry if this sounds so depressing but it's how I see the world now after being so mistreated by the medical profession

  • My GP treated my B12 when the level was 176, he said anything under 200 was low. If you need more advice contact the Pernicious Anaemia Society, their website has a symptom list you can print out. You can tick all that apply to you and take it with you to your Doctor, they also have the latest recommendations for treatment. Guidelines that your GP should be following. Low B12 and thyroid go hand in hand, the symptoms are similar too. If your B12 is too low the thyroid meds won't be working properly either. I do hope you get the help you need. MariLiz

  • Eek - hope this helps - can only say how it was for me! My B12 came out at 210 - but I had been having neurological symptoms and plenty others beside. All this was 15 years ago. Compared to many folks here, my GP was fantastic. Although my B12 strictly in range at the time - he sent me for a Schilling test which 'proved' I don't absorb vitamin B12. I have been on injections ever since.

    Good wishes to you

  • thank you all who replied to my post on b12 I also have neurological symptoms plus my nails keep coming away from the nail bed i am so nervy and anxious even when my T4 reduces to a lower level, I will tackle my G P about my low B12 results again but its just like hitting a brick wall he says I havn,t got pernicious anaemia and I don't need B12 when I suggested I self medicate he said not to do so as this can cause problems !!!!! so I ask all you knowledgable folk here is it safe to supplement myself can it be dangerous to take it myself and will it affect my blood test results. where can I buy sublingual b12 ,also can I request a shilling test ( not sure what that is) from my GP . what reaction can I expect from supplementing, i am so unsure how to go about this but i know i need some guidance thank you all for so much help and information

  • I replied earlier and gave you the link to the B12 Deficiency website - please do take time to have a good look around. As I said there is everything you need to know about B12 Deficiency and more. You can download the Guidelines for your Doc - see below....


    The first line discusses the fact that GP's must take notice of the CLINICAL signs and not just the blood test.

    In the link I gave you earlier you can click onto a questionnaire which indicates just how deficient you are. Also additional test required. Take a look at the films too....

    We have to read and learn in order to help ourselves. Knowledge enables us to challenge those that allegedly know more than us - and to ask the correct questions - information is power....

  • what if my GP refuses to do the shilling test , can I have this done privately ,I have read all the articles you suggested and feel I need to take this test so I know how and if I have B12 absorbency problem thanks for guiding me through this

  • You are welcome ! Am not sure about the Schilling Test - I live in Crete so had to rely on the basic serum test and symptoms. Oh and I do have Crohns and Hashimotos and my Terminal Ileum removed 42 years ago - the bit where B12 is absorbed. Did anyone tell me - NO. The damage is done. Hence I am passionate about informing others !

  • After a cursory look I couldn't find where to get the Schilling test privately in the UK. Maybe you can get it somewhere but I did find that Lab Tests Online have this to say at the end of their explanation of B12 and Folate tests:

    "The Schilling test was once used fairly routinely to confirm a diagnosis of pernicious anaemia as the cause of a vitamin B12 deficiency. It is still requested occasionally but has fallen from favour because it involves giving the patient radioactive vitamin B12. The Schilling test has been replaced, in part, by the measurement of intrinsic factor binding antibodies and parietal cell antibodies."


  • Your doctor is an idiot. And ignorant. Taking B12 will not cause problems - you can't even over-dose on it because it is water-soluable. I've had to supplement myself, and I feel so much better for it. How does he know you haven't got Pernicious Anemia? He hasn't even tested for it. So sick of these morons playing god!

  • hi grey goose I am so relieved to know I cant overdose on B12 I had my 4 monthly general blood tests as well as my thyroid function test done when I asked him about the results he brought up all my results on screen and said everything was ok I didn't have pernicious anaemia my folate was ok and B12 ,I am going to ask for a copy of these results so I can post and let you see them, one more thing will I have any side effects by taking B12 and which would you recommend

  • Well, you shouldn't have any side effects - although it has been know. But it's rare. If you get any, just stop taking them. And then you can talk about it on the Pernicious Anemia site, because they are very knowledgable. But there shouldn't be any problem.

    Myself, I take Solgar's sublingual methylcobalamin 5000 mcg, which is the best absorbed. Tastes nice and, as far as I know, it works!

    Yes, it would be best to get all the figures so that you can see them yourself. :)

  • I saw this post yesterday and wanted to reply because I have recently been suspecting a B12 deficiency in myself. I am not a vegetarian and always assumed that I get enough in my diet. I also regularly take B complex. However, I am suspecting an absorption issue  (another story).

    This is when I started looking for the best way to supplement. Marz's post is great because she advises taking specifically Methylcobalamin. This is important because most B12 supplements are in the form of cyanocobalamin which appears to be the least effective way to supplement. I don't usually believe everything I read on the Internet but discovered these websites the night before this post came up. It seems worth considering. I am still going to check some scientific journals on this subject. And in the mean time I am buying Methylcobalamin.



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