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Pernicious Anaemia Society
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B12 deficiency. How long before permanent nerve damage is done?

After advice from your good selves and the b12 deficiency site I asked and after a bit of a fight because my last b12 test was 'in range' I managed to get blood tests done today for B12, Ferritin,Folate and MMA. I can't get my surgery to budge though on giving me b12 injections yet, even though I have had neurological problems for several weeks. My husband told the doctor that he is breaking N.I.CE. guidelines by not allowing me these injections but they refuse to treat me until the test results come back. Can anyone tell me how long an MMA test takes to come back, please? I cannot wait for weeks like this.

The pins and needles/burning in my legs is so bad , I cannot sleep and it's 24 hour pain that's scaring me now. I know I can buy the stuff to self-inject but I'm too scared of doing that myself and if I do that wont that mask a P.A. test if I needed one? I did ask for a test for that this time, as I have other autoimmune conditions closely linked to P.A. but presumably they don't think that's worth doing.

I've read so much about the need for treatment being started urgently if you have neurological problems and want to know how soon nerve damage can become irreversible . Can anyone enlighten me, please?

14 Replies

I'm in the US and the oft cited timeframe from my neurologists has been "six months from the time the neurological symptoms occurred." I also have nerve damage that may or may not be permanent. I've been under treatment for five months so far post PA diagnosis. As others here can attest it is systemic and may have a broad range of symptoms that come and go. PA is so individualistic that there really isn't one answer as it affects us all differently. Sounds as if a new doctor that is able to take into account your other autoimmune concerns as well if it is possible.

Please contact the PA Society and ask for assistance in making your voice heard. They are wonderful and it can only help. Being armed with valid medical information to make your case can certainly help. Keep pushing for answers and don't give up!

Best Wishes


Thank you for your response.

A neurologist wants me started on Topamax because he thinks its peripheral neuropathy down to my diabetes or Hashimotos and I'm waiting on my prescprtion any day but I'm not sure whether to put that off and go back and plead again for the b12 injections or just take the Topamax until the blood test comes back. I just don't want to mess up and if the Topamax stops the nerve pain, isn't there a danger that gives them even more reason to deny me jabs or further b12 or P.A. Investigation?

This morning, the pain is even worse and I have to go to the hospital for a thyroid nodule biopsy. I'm tempted to do a sit in in the haematology department afterwards with a large sign saying 'save my legs'!!



You're right that supplementation can affect test results. I wasted a lot of money due to this.

I've assumed you're in the UK.

My top tip is to talk to the PAS. The chairman is very sympathetic.

Head office: 01656 769 717 If you leave a message they will get back to you.


The library section on the PAS website has some interesting documents.

If you have neuro symptoms, you should get an injection every two days until improvement stops then an injection every two months.

Has your GP checked their copy of the BNF (British National Formulary)? Info they need is in Chapter 9 Section 1.2 I think.


if you haven't already, google "BCSH cobalamin and folate guidelines". These were updated in 2014 and your local CCG (Clinical Commisioning group) will be able to tell you if the NHS in your area is following these guidelines.

It's a very interesting document which admits there are difficulties with the way PA and B12 deficiency are diagnosed.

Have a look particularly at the diagnosis flowchart in the BCSH guidelines on page 29, I think. Perhaps your GP would like a copy?

The other documents that your GP might find helpful are


The BMJ article basically says that symptomatic patients should be treated.


If you still don't get the help you need then you could talk to your MP.


Wow. Thank you. I have printed off a UK NEQAS b12 alert dated Feb 2014, which is a few sentences long but very succinctly says what I think I need and am seriously thinking of going to haematology dept whilst I'm at the hospital today, on the off chance I may get somebody clued up on all this.

Thank you so much for taking the trouble to write such a lengthy, helpful reply.


It is irreversible I'm afraid. You can ask to go to the pain cilinic. They may help you better untill you get b12 injections.


OMG. Please tell me there is some chance of recovery. from the injections.


Apparently, nerve damage it depends on severity of the deficiency and duration but, in any case, everyone here would sympathise with your concerns that you be diagnosed and neurological symptoms treated quickly - your husband is quite right, they are not following BCSH, UKNEQAS guidelines or the latest BMJ research.

I agree with others here about contacting the PA Society for assistance and you could also write to your doctor, enclosing the latest BMJ research document summary (given here again) - they may take more notice if spelt out in black and white (being sued is apparently a concern to them I'm told) :


Cmim/BMJ document. " Summary:

* Vitamin B12 deficiency is a common but serious condition

* Clinical presentation may not be obvious thus leading to complex issues around diagnosis and treatment.

* There is no ideal test to define deficiency and therefore the clinical condition of the patient is of utmost importance."

* There is evidence that new techniques, such as measurement of holotranscobalamin and methylmalonic acid levels seem useful in more accurately defining deficiency.

* If clinical features suggest deficiency, then it is important to treat patients to avoid neurological impairment even if there may be discordance between test results and clinical features.

Severe deficiency shows evidence of bone marrow suppression, clear evidence of neurological features and risk of cardiomyopathy.

It is important to recognise that clinical features of deficiency can manifest without anaemia and also without low serum vitamin B12 levels. In these cases, treatment should still be given without delay."

PS. From the book, " Could it be B12? " - "deficiencies begin to appear in the cerebral spinal fluid below 550 pg/ml." "For brain and nervous system health and prevention of disease in older adults, serum B12 levels should be maintained near or above 1000 pg/ml.

PS. Can't help feeling Topamax might obscure the picture when you look at the side effects....

Very best wishes for a good outcome


"Please tell me there is some chance of recovery. from the injections."

My understanding is that response to injections is very individual.

Have you read "Could It Be B12" by Sally Pacholok?


From what I've read I think some people experience some recovery even after a long period of being ill.

There are some interesting videos about B12 deficiency on You Tube.

1 like

how long did you have the neuro symptoms for? Did treatment this past year help you, any relief at all and how much this past year? Thank you.



I've had neuro symptoms for not far off 20 years. Sadly took me many years to link it to B12 deficiency though.

Although I never wanted to self treat in the end I had no option as I failed to get NHS treatment. To be fair to GPs I was not an easy case. Apart from an initial diagnosis a few years ago of b12 deficiency (not diet related) when I already had multiple neuro symptoms (for which I just had 5 or 6 loading doses then no more) most of my test results have been negative or normal range.

Some of my neuro symptoms went when I started to self treat a few years ago, some improved and some stayed the same.

My personal belief is that I have some mild permanent nerve damage eg permanent tingling but have never been able to prove this as typical neuro exams always came out normal. I will add that no neuro ever tested what happened when I had my eyes closed...see an old thread of mine on "proprioception" if interested.

My IBS improved when I gave up gluten, some other symptoms improved as well. Coeliac tests were negative but I did find out that some people can still have Coeliac disease even if typical Coeliac tests are negative. I do wonder sometimes if I am Coeliac and if my neuropathic symptoms might be due to Coeliac disease. Not willing to start eating it again though to go through further tests.



Have thyroid disease and diabetes been ruled out?





just another thought...burning sensations in the feet can be a sign of Grierson-Gopalan syndrome which can be associated with B12 deficiency.


Oh, that's a new one on me. I'll look it up. Thank you.


Have just read through the above (very informative ) thread. Firstly Thank you for being so helpful.

My B12 P.A diagnosed 23 years ago. Initially had loding doses then every 12 weeks which were reduced to 8 as I was struggling.

Unfortunately 10 years ago I broke my neck so a lot of the B12 symptoms were diagnosed amongst these symptoms.

Thankfully, I recently found your site.

I can now self manage as I moved to Spain 12 months ago where I can buy injections over the counter.

My advise to the author trying to get answers go to your haematologist again. I found out everything I needed to know when I had a complete analysis.

Its difficult, trust me I know, when you are feeling so ill. Just listen to your instincts I'm so glad I did, as I wouldn't be here if I had trusted the GP service.


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