Pernicious Anaemia Society

Active B12 test

Hi I wonder if anyone could help? It has taken years to get my daughter diagnosed as having low B12 and at last have got her on 3 monthly injections. She has been having to take anti depressants as she is so low from feeling so poorly all the time. It has really affected her time at uni. I have also recently bought her the sub lingual spray which she uses and I think it makes a difference. She has had intrinsic factor tested and is negative for antibodies. The thing is, I am always afraid they will take the injections away from her. I think 3 months would be the minimum she could stand. If we paid for her to have the Active B12 test, would she have to stay off the spray and also would she have to stop injections to get a correct result? I just feel if we had this result as well, it might be helpful as future evidence but dont want to put her through it if she has to give up injections etc.


Any advice would be brilliant. My sister and niece also suffer from this and dont get me started on how they have fared!!

11 Replies

Hi yes she would probably have to miss at least one injection. If she can't get more from GP she might be better considering spending money on getting own supply of sublingual, injections etc. as I know others here do. Personally I would not risk coming off mine. Good luck!


Sometimes antidepressants (SSRIs) can have a negative impact on folate levels and as folate is needed in order to be able to use B12 properly this can have a negative impact on the effectiveness of B12.

IFA isn't a very senstive test and is only about 50% accurate so having had a negative result doesn't actually rule out PA - but GPs generally aren't aware of that (though think it is in the guidelines). Family history actually makes it quite likely that your daughter does have PA but the test just hasn't picked it up that time round.


Thanks so much, I will see what she wants to do, we have an appointment with a sympathetic doctor soon. If anyone has ever had the test that measures the active B12 while they have been on 3 monthly injections, please let me know how long you had to wait after your last injection. Thanks for the help😍


Has your daughter had an MMA test and homocysteine test?

Has she ever had a "blood smear"...she should be able to get this done privately as I think it's rarely done on the NHS. This should show up the range of sizes of red blood cells. B12 deficiency causes large red blood cells.

My personal view is that it's probably best to be off supplements for several months before tests. I wasted a lot of money having private blood tests for active B12, MMA and homocysteine and then found out that the results were probably compromised by the fact I was supplementing.

The following books and websites may be helpful.

Head office: 01656 769 717 Chairman of the society is helpful to talk to.

Could It be B12? by Sally Pacholok

Pernicious Anaemia: The Forgotten Disease: The Causes and Consequences of Vitamin B12 Deficiency by Martyn Hooper

Living with Pernicious Anaemia and Vitamin B12 Deficiency by Martyn Hooper


Pernicious Anemia can run in families although not everyone will suffer from it, it is known as a "familiar" illness. I understand what your daughter is going through as I had it for 15 years before finally being diagnosed when it almost killed me at 29 as my blood count was so low I actually turned green.

I was also put on anti depressants but later found out that Sertaline contains a blood thinner and due to my pernicious anemia should never have been taking it in the first place.

Under no conditions would I ever recommend stopping the b12 injections. Mine were stopped for 3 years until last August when again my levels were so low that it almost killed me and I ended up in hospital for 5 weeks. At 34 I am now unable too walk very far and have too use a stick at all times, as well as my spine being damaged and limited feeling and movement in both of my hands and feet. I am now on a form of morphine long term due too the pain caused by the nerve damage. My hair is now starting to grow back as over 50% of it fell out.

I cannot go 12 weeks between injections so I have come too an understanding with my GP, they will provide my b12 ampules and change my sharps box when needed and I give myself my injections once a month when I need them, so far this system seems too be working out.

A website called "no more panic" maybe of use too your daughter. It is a safe place too talk about health issues such as depression with other people also have depression and can provide support and a chat room for help and advice about how too cope with it.

1 like

Thank you for posting here. I had a test taken for b12 deficiency which shows normal levels. But I feel absolutely horrible and have had every blood test ran on me in the past three years. I wake up in pain every single day and I am now depressed and have anxiety problems caused by all this. The celebs helps for that a little bit but all my physical symptoms are still here and not getting better. But your story really makes me feel like I'm not just crazy. And it's not all in my head. It can cause physical illness as well and mental.


I know exactly how you feel. Some days I was fine and others I could barely get out of bed in the morning. As b12 levels are not checked on standard blood tests it took 15 years before mine was diagnosed. But I have found it so hard too get the treatment that I need as almost every GP will only give the b12 injections every 12 weeks (apart from loading dose).

I have found art therapy helps with the depression and my card making is a good form of complex physo for the nerve damage too my hands. Some local groups then benefit from my cards as raffle prizes or for special occasions. It then makes me feel good that someone else has got something out of my depression.


That's wonderful to hear. Are you taking b12 supplements or a sublingual spray or anything. And are you taking folate as well.


I give myself my b12 injection once a month and take 5mg folic acid daily but nothing else. I try to avoid daylight as much as possible as my skin burns really easily


Skip whatever supplement you'd not expect to continue, regardless of the test result. But don't skip, just because you're going to have a test. Don't try to force a bad result. You want to feel well. And if it turns out that despite an excellent test result, you still feel ill.... you have new information. e.g. if you continue all the supplements including injected , right up to just before the next planned dose, and have the test and the test result is low or normal... then you know to increase or maintain the dose; and test again in a few months. If the result is too high, then you know to reduce the dose; and test again in a few months. Just make sure the doctor interpreting the results knows about all the supplementary sources, so they can interpret correctly what to do next. Supplements have a predictable half-life , so it shouldn't be difficult for a doctor to interpret the results correctly.

1 like

Thank you all so much for all your help and advice. It's nice to know there are people out there who are trying to help us. I just wish someone had listened when I first took my daughter to the doctors when she was 10 so she wouldn't still be struggling at 21.


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