Pernicious Anaemia Society
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Test for PA after supplements?

Hi there, I've been doing fine taking 10,000iu per day B12 sublingually and in order to reduce my outgoings I decided to halve that to see if I could get by on less. The result was that within two weeks I had the headaches and pins and needles again. Before supplementing my B12 had got down to 270 but my GP thought that was OK despite my symptoms. Thanks to this site I realised that I ought to start supplementing. I have Hashimotos too. My GP did ask for an intrinsic factor test and parietal cell test, they did the parietal test (neg) but not the intrinsic factor! My GP is very helpful and will do any tests I ask for within reason but I don't know what will help to decide if it's B12 deficiency or PA now that I'm supplementing (back up to 10,000iu now).

Many thanks for your help

4 Replies

Have you had your Folate level checked Lozzie611 ?


Thanks for your response clivealive, I had my erythrocytaire folate and ferritin done about six weeks after I started supplementing, the folate was 307 (140-628)and ferritin 66 (50-235). I don't know if that helps, I'm hoping there's a test I can ask for besides intrinsic factor antibodies that will establish whether I have PA or not now that I've started supplementing. Thanks again for your help.


IFA is the test for pernicious anaemia. You need to stop supplementing for a week to 10 days before the test for result to be useful - details are in the pinned posts.

IFA is prone to false negatives about 50% of the time, so a negative result doesn't rule out PA.

You would need to stop supplementing for several months for serum B12 test to have any meaning - and you would probably find yourself feeling very ill and unable to function long before you got to the point where the test would mean anything. This a test for the B12 deficiency that PA causes. The symptoms of PA are the symptoms of the b12 deficiency that it causes.

There are other absorption problems that can lead to a B12 deficiency - PA is the most common


Thank you Gambit, I didn't know I should stop supplementing before the test so that's really useful information. The thought of giving it up for any longer and getting the symptoms again makes me shudder so 10 days will be long enough!


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