Active b12 test & high b12 blood results....


I have been feeling very unwell for a few years now and backwards and forwards to the docs never helps, docs think its all in my head but when I cant walk more than 10 metres and feel happy and certainly not anxious I find it very hard to believe there is nothing wrong...

Anyway the only thing that ever shows up as abnormal is high b12 and also folate... doctor says it must be supplements and when I say I don't take supplements he then says it must be my good diet and then I tell him I have been veggie for over 20 years and cant cook well as I have to energy to cook! The doc then tells me to try beta blockers.......... Arghhhhh

I have all the symptoms of a b12 deficiency so is it possible to have a deficiency and high blood levels if the b12 in my blood is not active?

I would like to get a blood test to check the active b12 in my blood.... Would this help in my situation? Any other tests that may help?

I am worried also because I have read the horrible things that high b12 can indicate but my doctor says I am fine........

I am so frustrated with feeling so bad... These are some of my symptoms (well what I can remember off hand as memory is also a big problem!)

Tingling in feet




Lack of energy and any physical activity is debilitating

Hyper reflexes

Headaches (pains in back of head).....

Bleeding gums

Ringing in ears

Mt TSH is slowly rising (is now 3.16) but my doctor says I will never have a thyroid problem as antibodies and T3 and T4 levels are normal.....

Thanks for reading xxx

Is the active b12 test available on NHS?

5 Replies

  • Hi,

    Yes the Active B12 test is available on the NHS..sort of anyway, you have to pay £15,- plus sure the test itself costs far more..but you do need a request from your GP to have this tests.

    For more info, see:

    The majority (up to 80%) of serum vitamin B12 is not bio-available. Current assays measure total vitamin B12 which leads to a grey area where deficient patients can be missed - there is a poor correlation between circulatory total B12 and B12 status at the tissue level. Conversely patients can inappropriately be classified to a deficient state with the inconvenience and expense of long term supplementation regimes.

    The cost of this assay will only be slightly more than a standard serum B12 assay. It will complement GSTS' serum methylmalonic acid assay which is a functional marker of B12 at the tissue level that GSTS is the only service in the UK to offer.

    Those wishing to be tested must attend the phlebotomy department at St Thomas' Hospital with a signed letter from their GP requesting the test.

    For more information on the Active B12 (holotranscobalamin) test at GSTS please contact the Nutristasis Unit at: or phone Denise Oblein on 020 7188 7188 ext 52471 or you can visit the Axis-Shield website.


    It is possible to have a high serum B12 reading but actually be def in active B12, some explanation see:

    B12 status confounded by haematological disorders

    Patient CCM was an 87 year old female suffering from Non-Hodgkins lymphoma.

    Patient was severely anaemic with high RDW and low MCV indicating microcytosis.

    However the ferritin level was very high so there was no reason to be microcytic.

    Total B12 was high at 373 pmol/L so patient appeared to be B12-replete. However, the Active-B12 was severely depressed at only 12 pmol/L.


    Patient was severely B12-deficient, even with a high Total B12 level. Abnormalities in transport proteins are evident in many haematological disorders, in this case affecting B12 transport


    You see from above pasted that there can be other markers, such as MCV and RDW etc, it can help to get copies of your bloodtests and then look to see what has been tested and what is abnormal etc, explanation of bloodtest results can be found here:

    Explanation of FBC:

    I hope this helps you further,

    Kind regards


  • Thanks so much Marre, that is really helpful!

    Thing I am worried about is because I feel so ill it is difficult for me to get anywhere at the mo.... Can just about manage docs surgery with a friend and taxi so not sure about the getting to St Thomas.

    Are there any other tests that may indicate improper usage of b12?

    Thanks xxx

  • Hi Cazz,

    Homocysteine is raised in folate and or B12 def, MMA (methylmalonic acid) is raised in B12 def..but these tests are seldom done on NHS, cost and arm and leg done privately..Try ringing or e-mailing GSTS and find out if you can now post a sample, collected from your surgery..know they are busy trying to get that organised, just not suire if it bet is to ask them!

    They are specialists, they can possibly advise you further than I can, I found them very helpful and kind..

    Kind regards,


  • See:

    But the NHS does not seem to give these tests much value, doubt your GP would...this is not terribly helpful advice, see:

    Common Questions

    If I have an elevated MMA, why might my doctor hesitate to diagnose me with vitamin B12 deficiency?

    Can either blood or urine be used for the MMA test?

    1. If I have an elevated MMA, why might my doctor hesitate to diagnose me with vitamin B12 deficiency?

    If your B12 test result is in the lower end of the normal range and you do not have significant symptoms, your doctor may feel that you have adequate B12 and will rely on these findings rather than on the elevated MMA. This may be especially true if your homocysteine level is normal. Your doctor may want to monitor your condition over time. He may be reluctant to start you on what could be lifelong treatment with B12 injections and/or oral supplementation unless he feels it is truly necessary.

    ^ Back to top

    2. Can either blood or urine be used for the MMA test?

    In most cases, it is okay to use blood or urine for this test. Sometimes, your doctor may want to test both your blood and urine in order to compare the MMA results. Since homocysteine is a blood test, it may be more efficient to collect blood for both the MMA and homocysteine tests when they are requested together.


    There are, as of yet, no established guidelines for homocysteine testing, and routine screening is not recommended.

    Occasionally, a doctor may also request a homocysteine test in the investigation of suspected vitamin B12 or folate deficiency.


    So all not very likely to be done by NHS GP unfortunatly..

    KInd regards,


  • Thanks so much for your help Marre!!!

    I will call them tomorrow and take it from there, will let you know - thanks again!!! :) x

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