Pernicious Anaemia Society
14,661 members10,437 posts

Up to date with injections but still having symptoms

Hi Everyone,

Is anyone else having this problem? I'm up to date with Vit B12 injections at my surgery (Ihave them once a month) but have started to have the symptoms again and am off work at the moment, excessive tiredness, brain fog, dizziness, numbness in my left toes. Since changing from injections once every 2 months to once a month last year, my general health has been a lot better but now I feel like I'm back at square one. Can anyone recommend a specialist to go and see preferably north of London please? Thanks.

7 Replies

Difficult to gauge from your post what sort of a difference going from every other month to monthly has made.

There is a thing called 'functional B12 deficiency' which can result from the body responding to high levels of B12 in blood as a result of supplementation - an auto-immune reaction that leaves you with high B12 in blood but none at the cell level.

However, its also true that people vary a lot in how quickly the get rid of B12 from shots and it may just be that you are one of those people who need it more frequently even than monthly.

Sorry but don't have any recommendations re specialist - beyond the possibiltiy of looking into a referral to the neurology department mentioned in the abstract.


HI Gambit,

Thank you for replying. When I was having an injection once every two months I was still very tired and suffered with a lot of minor illnesses, plus the dizziness and brain fog of PA very often. After changing to more frequent injections (monthly) I haven't had many minor illnesses and the tiredness and dizziness reduced. I've seen my doc recently and he thinks my tissues aren't taking up the B12 in the injection effectively so we are trying to find somewhere locally I can go for the blood test for that.


Hope it goes well.


As well as knowing your B12 levels it's also useful to know your folate and ferritin levels.

You need good levels of folate and iron for uptake of B12 to be good. I always get copies of my blood tests.As well as B12, folate and ferritin, I get copies of FBC (Full Blood Count)

"my general health has been a lot better"

Have you increased your activity levels because you were feeling better? More exercise means more B12 used up.

Some people have an auto-immune response to high levels of B12 in their blood. I think Gambit knows about this.

Sadly some people if they have to wait a long time for diagnosis may experience some permanent damage.

Have you ever had thyroid tests? Coeliac tests?

Have you started any new medicines? Some drugs interfere with the uptake of B12.


HI Sleepybunny,

Thank you for replying. My ferritin and folate levels are slightly high. My blood tests over the past few years have shown gradually increasing ferritin levels each time.... not sure what that means.

Yes, my activity levels have increased with a promotion at work and more responsibility... So maybe that's the reason I'm not very good at the moment.. trying to do too much maybe..

I've had Thyroid tests and Coeliac, both negative. No new medicines.

Thanks again.


The Coeliac UK website mentions that is is possible to test negative for Coeliac disease but still have it. I think if coeliac symptoms continue GPs are supposed to test if you have IgA deficiency.

If you have an IgA deficiency I think you don't make the normal coeliac disease antibodies.

I have read that there may be an IgA deficiency link with pernicious Anaemia.


HI Sleepybunny,

Thanks v much. I will look into it.


You may also like...