B12 test results - advice please!

I was tested for B12 back in June and the result was 428 (197-771) and have since been supplementing as it was under 500 (I was not supplementing before the test). I have just tested my b12 again result has gone down to 371! I did stop supplementing however for about 4 weeks before this latest test as I thought you were supposed to break before testing. I have since read that I don't think this was the right thing to do and if I wanted a baseline result I should have waited 4 months (I didn't, just wanted an update).

I have symptoms of skin crawling/tingling/numbness. I was previously using a better you spray to supplement. Should I now, just start supplementing with some methylcobalamin lozenges or would there be any benefit in getting an active B12 test? I don't really want to wait another 3 months to test for a baseline result.

Would welcome people's views on the best next steps. In case it has a bearing, my results also indicated that I may have an under active thyroid developing and have borderline low and low in range T4 and T3, with high in range TSH. Have posted on thyroid forum and they suggested I post my B12 question on here.

Many thanks all!

7 Replies

  • people vary a lot in how quickly the excrete excess B12 - and if the sublingual spray didn't help you then I doubt that lozenges will be any better.

    428 v 371 is probably just about in the noise range for results so the fall may not be significant however, the fact that the supplementation didn't push your levels up a lot higher does tend to imply that you have an absorption problem

    suggest that you read through the pinned posts and put together as much information as you can on the fact that B12 serum test isn't an accurate guide to B12 deficiency and needs to be evaluated in light of symptoms - eg UKNEQAS alert and BCSH guidelines - and put together a list of your symptoms and share with your GP and try to get a proper diagnosis of a B12 absorption problem which will be treated with injections of B12.

    it can be very difficult getting through to GP so please use this forum to get support if things don't go well

  • Is it worth just paying for an active b12 test? Will this tell me if I am not absorbing?

  • I should add as well that I realised after buying it that the spray contains sorbitol which I can't have as I have ibs and am on a low fodmap diet. So I was spraying it leaving it about a minute to and then spitting it out. Lozenges could therefore work better. Not sure whether to just go for lozenges or test further now.

  • personally I think there is enough evidence that you aren't absorbing and that the active B12 test is likely to be a waste of money. It suffers from one of the same major pitfalls of the B12 serum test - which is that it tells you what is happening in your blood, not what is happening at the cell level which is where B12 really counts because that is where it is used - blood is just a transport system.

    More likely that MMA and homocysteine would be better indicators at this point - by products that build up if the body doesn't have enough B12 to recycle them - but as they can be raised due to other things (eg folate in the case of homocysteine) they aren't front line indicators.

    You could also try for IFA - looking for the antibodies that are characteristic of PA - the commonest cause of B12 absorption problems - but it gives false negatives 50% of the time - so a negative doesn't actually mean that you don't have PA ... and PA is only one of the possible causes of a B12 absorption problem

  • Will an active b12 test tell me anything if I was supplementing 4 weeks ago?

  • Sorry am really confused - you say MMA/homocysteine would be better indicators but then say they aren't front-line indicators? Sorry I don't know what you mean by this?

    If I should get an MMA/homocysteine test, where can I get this privately in the UK?

    Thank you!

  • In my limited knowledge, thats the whole problem. THERE IS NO ONE TEST TO SAY, YUP PA. The doc is supposed to weigh up all these tests, take what you say your symptoms are (expecting docs to understand ranges and false positives, believing you !!) and make a decision on what to do. Helpful? No, just as confused.

    Thats normal.

    Its hard work, but educate yourself on the pinned posts on the right of this page. Get to grips with all the tests, read the guidelines and note your symptoms on the symptom checker then get ready to approach your doctor, if you think you have B12/PA. be prepared to defend your low B12 level, which he will probably say is "in range" and that we must "stay within NICE" guidelines" which are acknowledged as being in need of updating.

    Sorry to deflate you but I wouldnt simplify it. It is counter productive. You get your hopes up and meet the blank wall of docs who adhere strictly to blood test results which, in this case are not 100% reliable.


    Correction, most docs! Some listen and are willing to learn and help.

    The thing is this is a timing issue too. Simply put, what should happen is: do the battery of, shall we say "indicator" tests, take note of symptoms, if suspect B12/PA start the injections and if nothing happens after an agreed length if time, no problem. No damage, no harm at all. Stop. Sounds sense. The alternative is deterioration whilst being doubted. Ill health and frustration.

    This organisation is doing so much to help but it seems to me that the more of us that challenge the docs with consistent, enlightened, informed opinion, backed with the expert documents given here, perhaps there will be a shift and the tide will turn.

    For sure, sitting back and leaving it to others is NOT the answer. We must be vocal. We must be tireless (ha ha fatigue!) we must not give up.



    Sorry to cause any upset but I for one have had enough of being blanked by ignorant, often lazy doctors, when I present my autoimmune diseases. I am an expert patient on some of them but I vow to be so EVERY time I go to the doctors with my worries, symptoms and researched suspicions. If they wont do the work for their own professional pride, I WILL for my health.

    Over to you. Ready to look right and start reading?

    Love to all of you frustrated, oh so tired, dispirited folk who need the help of doctors, not their bemusement


You may also like...