Pernicious Anaemia Society
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New Active B12 blood test

Is anyone still symptomatic with B12 serum blood test showing good levels? Has anyone then has the new Active B12 blood test which showed they were deficient? I'm very unwell at the moment but getting nowhere as my B12 serum is showing 1000. Have tried supplementing with B12 sub-ligual tabs but didn't notice any difference. Has anyone had the King's blood test done?

3 Replies

Hi Irene,

It is important to have a bloodtest if you are not doing well, it is possible you may have now also become iron def and or folate def, which all can mean you will not feel well. Also hypothyroid is a condition that regularly comes with PA (or the otherway round), so thyroid function test would be useful. Unfortunatly once you have one autoimune condition you are more susseptable to more, although it does not mean you will get more..just a possibilety, so testing is essential if you are not doing well on current treatment.

My Daughter had the Active B12 test because she was taken off B12 jabs, as her levels were "normal" (serum B12 300), and she hates them. After 7 months of no B12 treatment (having been on B12 jabs for 3 years) she agreed to have the Active B12 test done (for me), the result suggests she was B12 def again, After 7 months her serum B12 had sunk to 230.. She got one cold after the other, infections etc, was became iron def again etc.

Her results re: Active B12test, was 28 pmol/L (lab range 35 - 141), Active B12 concentrations under 25 pmol/L suggests B12 def, vitamin B12 can not be excluded if Active B12 (holo TC) concentration is inbetween 25-35pmol/L, because of her result her blood sample was referred for mathylmalonic acid (MMA) analysis, her MMA was 433 nmol/L (ref range 73 - 271), MMA is above the upperlimit this result suggests functional vitamin B12 def at tissue level.

So she is back on B12 jabs for life now. Not that she is good about getting them on time..

So some are fighting to get more frequent B12, whilst others are fighting to get off them..

I hope this helps,

Kind regards,



Thanks Marre I have had a full set of bloods done by the hospital but the B12 serum shows good levels at 1000. However I am experiencing typical B12 deficiency symtoms. I do have AI thyroid problems but the test for this showed all is well as did the iron/follate and other blood tests.

The hospital are telling me what it's not and I'm no nearer finding out what it is! Before I push to get the active B12 test authorised (which I think will be a battle) I wanted to know if it was worth while. Thanks for sharing your experience it certainly does help.



Consider getting your RBC folate checked. An elevated RBC folate level may mean you have a methyl-block and your serum B12 levels would be inaccurate.


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