Pernicious Anaemia Society

Advice, please!

I am due a blood test next week, then my 2 monthly B12 injection, the first since the loading doses. I have been much better in general, but have definitely gone down hill recently, so need to convince my GP that I need more frequent top-ups. I know I am deficient, but I don't know what caused it or if there's anything else going on, so which specific tests should I ask for?

5 Replies

Do you have Pernicious Anaemia ? If you do that is the reason your levels are low. How many loading doses did you do?


I don't know if I have PA, just that the serum B12 was down to 83, so I had 6 loading doses and told to go back in 3 months. When I complained that it wasn't enough and quoted the NICE guidelines, I was given 8 more shots and put on 2 monthly top-ups.


Anyone else with advice, please?


Hi ednotdave (interesting name :-),

I amnot an expert, I have been recently diagnosed with PA, and my B12 was 65 ( had been 103 in 2011 but that is another story).

I had alternate day ( so 3 times a week) loading doses until my doc decided I must be full - idiot.

so - I have had to do a lot of research and ask a lot of questions here and on the PAS society forums so that the kind folks could help me out as my doc is pants.

anywho - as to your question - the test you are looking for to help identify Pernicious anemia are:

Intrinsic Factor Antibodies

Intrinsic factor is what is needed to absorb B12 from food.

Please remember - you may have to educate your doctor here, as my GP did not know this - Pernicious Anemia IS NOT diagnosed by anemia or Macrocytosis ( large red blood cells), and has not been for many years !

You can have pernicious anemia without having Iron or folate anemia, and also without having enlarged red blood cells - if he argues with you about this - tell him to speak to the Pernicious Anemia Society - they have many research papers, links and are more than happy to educate the outaded ideas of GP's.

B12 is NOT present in anything other than animal food - so your B12 may have dropped so low if you have been a veggie for a while.

It can also drop for a number of reasons, pregnancy, other illness - in which case it should go back up.

B12 deficiency from Pernicious Anemia does not get better on its own or via diet - you simply cannot absorb B12 from the gut - this can happen at any time in your life - it is an autoimmune disease.

so - next steps:

get the doc to test for intrinsic factor antibodies - if you have these - you have Pernicious anemia.

If you do not have these - there is another cause - check diet or any other illnessess (obstructed bowel and many more than I know of)

If you have pernicious anemia - you need to have loading dose UNTIL there is no further improvement.

when the doc decides that then he can put you on as little as 1 dose every 3 months (NHS guidelines), BUT he can still give you doses once a week - whatever he feels like - so it is up to you to battle with him.

I am in such a battle - my doc stopped for no reason and put me on one every 2 months with no follow up to see how I am doing.

Lots of people here will rtell you that you will notice when you are due, as the previous symptoms of mind fog, lethargy, constipation etc kick in like before - unfortunately for me - they never stopped - hence why I am upset with my doc.

The point is - you need to tell the doc how you felel, and give him a list of symptoms written down, tell him you have done your part by writing a diary and he needs to listen to you and ammend your dosage appropriately as the guidelines are just that, they are not a one size fits all patients.

If you show you have done your bit, that you are comitted to being a reasonable patient - he has no excuse.

I keep my fingers crossed for you and would love to hear how it goes, for me I have had bad experiences but others have found going prepared has helped their doctor give them the right level of treatment.

Best of luck, and BIG gentle Hugs,



Hi ednotdave,

You might find some answers in the new BCSH guidelines which have just been published, link here:

They should definitely be checking your anti intrinsic factor antibodies, but that only picks up 40-60% of sufferers. So if you test negative, but you have responded to the treatment, you are basically assumed to have "antibody negative PA" and require lifelong B12 treatment. If you skip to the flow chart on page 29 called Algorithm 1 you'll see what I mean.

Unfortunately it doesn't address the problems with treating PA and frequency of injections, treatment is still as per the BNF section 9.1.2. If the GP won't increase your injection frequency maybe consider doing your own. You will find lots of support and info on this Facebook group:

Also make sure you have good levels of folate and ferritin - B12 won't work properly without them. More good info here:



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