Pernicious Anaemia Society

Pernicious Anaemia tests skewed by B12 shots?

Hello everybody,

I have decided to go privately to be tested for pernicious anaemia. Not very happy with the cost, esp as I decided to do a full thyroid test. I have Hashimoto and they only test TSH. I am sure my GP is not going to approve the tests and I can't go through another battle!

I had about 19 B12 injections between end of September and 5th December? Will the results be skewed? esp the Active B12, the Intrinsic factor and the parietal cell antibodies?

Last January, when I first had neurological symptoms, my GP tested me for IF and parietal cell antibodies. Then, she said everything was normal and I need to do eat more food rich in B12. But when I asked for a printout, the result for the IF was negative ( no figures, no range... just negative) and there was no answer for the parietal cells - saying it was not required because the IF was negative but at the same time they said Result to follow? But it never followed? So, I am at a loss what to think. Do we need a test for parietal cell antibodies if we test negative for IF? why do GPs fail to acknowledge that these tests are not excellent markers of B12 deficiency and they need to treat the clinical symptoms - not the blood tests?

I have neurological symptoms and although they got better while I was having the injections, my GP decided to stop the injections. He said I had enough in my body to treat the neurological symptoms!!!! 2 months later on I am struggling. I am not as bad as before but I believe my B12 levels are dropping rapidly and that is why my symptoms get worse. I am 49 year old and It is terrifying that I walk like a 1year old when I get up first thing in the morning. I would like to be able to use these results when I see my GP to talk about it. I am also going to see a neurologist in 2 weeks. I am trying to be as prepared as possible for our appointment. I even thought of taking a video of myself having difficulty walking in the mornings! Will the neurologist think I am nuts if I walk in with a video, blood tests and the pernicious anaemia leaflets? Do I care? My first reaction is NO but then I am wondering what if they think I am hypochondriac and they send me home without giving me any tests?

Has anybody tried Medichecks? I will do the tests in a clinic and then post them. Do you think the GP will doubt the results if done in this way? I can hardly afford to go privately and if I am doing it, I want to make sure everything is done properly.

Thank you for listening!


7 Replies

Hi VickyB12 have you had your Folate level checked as this gets "used up" processing the B12?

I'm not a medically qualified person but I think you will probably have to wait quite a while after your last B12 shot before further P.A. testing is done. Hopefully others on here will be able to give you good advice.

I wish you well.

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Hi Clivealive, Thank you! yes, my folate level was very low, too. at the bottom of the range and so was my ferritin. I am going to test these as well.

When I had the B12 shots, I asked the GP to prescribe folic acid but when he stopped the injections, I stopped taking the folic acid pills because I understand they can mask B12 deficiency.

Shall I check Active B12 at least? Won't the doctors be able to assess the results based on the fact that I had supplemented 2 months before the blood test?

What a dilemma!

Thank you!



Results of Active B12 may be affected by recent b12 supplementation. Effects of homocysteine and MMA tests may also be affected I think. See 4th answer.

"Will the neurologist think I am nuts if I walk in with a video, blood tests and the pernicious anaemia leaflets?"

I wouldn't let it bother you. Think you're right to be well prepared. My experience of neurologists is that few appear to have a good understanding of b12 deficiency.

Have you thought about taking a copy of "BSH Cobalamin and Folate guidelines" with you? click on box that says "Diagnosis of b12 and Folate deficiency" .....should be on page 3 of listed guidelines.

and maybe a copy of PAS symptoms list with symptoms ticked?


Will neuro test for the following?

1) romberg test

2) proprioception problems

can a person walk heel to toe with eyes closed?

Have you got someone supportive, who has read up on B12, to take with you?

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Thank you!

Not sure what the neurologist is going to test.. 2 more weeks to go!

I will try to be as prepared as possible.... yes, I will give them a copy of the guidelines as well.

I have just bought some blood tests with Medichecks. I am going to check my Active B12 and I will take it from there. They said that I need to wait 12 weeks. almost there..

Thank you x



I'd suggest that you read up about proprioception problems and romberg test before neuro appt.

I saw several neuros and not one of them gave me any tests with eyes closed. Proprioception problems can be caused by b12 deficiency.

At that point I knew little about B12 deficiency. If I'd known more I'd have asked for a romberg test and the heel to toe test with my eyes closed.

Because everybody's different in how their body processes B12 etc, my personal opinion(i'm not a medic) is that some people may still have raised B12/Active B12 levels, weeks after an injection.

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Thank you! I will read about them... do you find the doctors get annoyed when we know what they are talking about and we have questions? Xx


"do you find the doctors get annoyed"

Yes definitely,

Pressure was put on me to leave a previous GP surgery. I was so shocked that I think I had mild PTSD for years afterwards.

It's got to the point that sometimes I get the feeling I know more about B12 and the UK guidelines than my GPs which in some ways is scary.

After my unpleasant experiences, I would always prefer to take someone with me to appts as I suspect that GPs /consultants are likely to behave more kindly when there is a witness present. Sadly I do not have someone able to come with me.

A supportive family member/friend can hopefully back a patient up when describing symptoms etc or step in if patient has brain fog or becomes emotional.

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