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Pernicious Anaemia Society
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Getting nowhere with B12..should I try self injecting

Hello, I am new to this and was looking for some advice about what I should do next in terms of the issues I’m having with the symptoms of a b12 deficiency.

I went to the doctors in March this year with joint pains in my legs, pins and needles, a numb right hand and dizziness. I got bloods done which came back with a b12 reading of 159 and no anemia. I got my loading dose (6 injections over 2 weeks) and by the end of it I noticed an improvement. The result of my intrinsic factor came back negative and was therefore told I needed no further treatment and sent on my way. A few weeks later i felt I’d gone back to how I was before and went back to the doctor who told me there must be something seriously wrong with me and they suspected MS and I was referred to neurology. After a lot of anxiety and panicking I eventually went private due to the long waiting times. I saw an excellent neurologist who totally understood the effects of b12 and was told this was the cause of all my problems. I had an MRI scan to check for other more serious conditions which came back clear and he was happy to start me on 2 monthly injections.

I got a blood test to check my b12 levels and was given the injection. Over the next few days I noticed a slight improvement again but this soon subsided. I then got the blood results back which showed a b12 level of over 500 before I’d even got the injection!!! And now my neurologist thinks there is something else involved.

Does anyone have any advice as to whether I could still be suffering from b12 deficiency or if it’s probably something else?

Also do you think it would be worth starting to self inject more regularly to see if it helps?

My current symptoms are:

Joint pain

Pins and needles


Tinnitus/ear pain

Muscle twitches

Vision disturbances (but not blurry)

Muscle weakness

Stiff shoulder/neck

Feeling of limping when walking


Brian fog/confusion/memory problems

I have quite a bad gluten intolerance but not confirmed as coeliac.

I am also aware that some of these symptoms could be caused by the anxiety I have in relation to this.

Any advice would be greatly appreciated, I feel like I’m going insane!


13 Replies

Don't think your neurologist really knows as much about B12 deficiency and treating it as you think he does.

Serum B12 is a pretty difficult test to use as a diagnostic tool before loading shots - it's really not a good diagnositic tool after diagnosis - normal range really doesn't apply as the loading shot introduces a new factor into the equation, the possibility of a reaction to high levels of B12 in the blood that means stops the B12 passing from blood to cells - it doesn't affect everyone but it does affect enough people to mean that 'functional B12 deficiency' is recognised as being a potential result of conditions that result in high serum B12 - such as liver and renal damage.

The most effective way of treating a functional deficiency caused by B12 injections is actually to keep levels very high - so that enough trickles through to cells.

These are a few articles on functional B12 deficiency that you might want to share with your neurologist.






some of these are only abstracts rather than full articles as the full articles are behind pay walls - your neurologist may have subscriptions to the relevant articles that will allow them to access the full articles


Many thanks for your advice.

Do you therefore think that my symptoms are still probably a result of the b12 deficiency and that continuing injections more frequently would hopefully make me feel better?


the fact that you respond to the injections would suggest that B12 is involved so more frequent could work - but there could also be other things going on.


Hi Elizabethrabbit. Hello and welcome. I'm sorry that you’re having such trouble getting treatment from your doctors.

First, I agree with gambit about your GP and neurologist's lack of understanding about B12 deficiency and it’s treatment.

The first thing to say is that there has been a 'missed step' in your treatment (and some misunderstandings - but more of that below).

There are two treatment regimes for B12 deficiency. The first is for those who do not have neurological symptoms: this is six loading doses and then injections every three months.

The second regime is for those with neurological symptoms (which you have): this is six loading doses and then injections every other day until no further improvement - perhaps for many months. This is the regime of injections you should be receiving.

It's worrying (to say the least) that the neurologist you saw was not aware of this.

So the answer to your question is - yes, more frequent injections would be needed to help your body repair and to help,you get well (though neurological repair take s longer than other forms of repair and can take some time). The fact that you improved following injections and then 'ran out' before the next one was due is a sure indicator that more B12 is needed. And the fact that you improved when having the injections is evidence of a successful theraputic trial - your GP should take note of this.

Some tips to get you started (then I'll leave some links to further information).

a) there are many causes of B12 deficiency (not just PA) - your initial B12 level was very low - your GP should be looking for a reason for your obvious deficiency (not just stopping treatment)

b) 40%-60% of people with PA test negative for IF antibodies. A negative IF result can not be used to rule out PA (unfortunately there is no gold standard test to 'prove' PA)

c) the serum B12 level of 500 prior to your second injection is quite low for someone who has just received six loading doses. After injections, B12 levels can be very high (mine are always over 2000ng/L), and can remain so for many months.

d) serum B12 levels following injections are meaningless (unless low) - they simply reflect the fact that large doses of B12 have been injected. So, following injections, serum B12 levels should never be used as a guide to whether further treatment is required. Your GP (and neurologist) should be looking at symptoms, not B12 levels. Just because your levels of B12 are now higher (be+ayes if the injections) it does not mean that you no longer have B12 deficiency (unless your GP has identified a cause that can be rectified e.g. infection with heliobactor pylori or medications that impede the absorption of B12 (PPI's, metformin etc).

e) 30% of people with B12 deficiency (whether due to PA or another cause) and neurological symptoms do not present with macrocytic (large red cell) anaemia. Many GP's assume that macrocytic anaemia is always present with PA and/or B12 deficiency. This is not the case.

e) the most likely cause of B12 deficiency is some sort of absorption problem - and this often means that other absorption problems are present too. Did your GP or neurologist test:

Folate: B12 and folate work together and if folate is low, your body cannot utilise B12 properly.

Ferritin (one marker of iron deficiency anaemia): iron deficiency anaemia can make you feel very ill indeed and, incidentally 'mask' the presence of macrocytic anaemia.

Vitamin D: again, a common deficiency that often accompanies B12 deficiency.

About the self injecting: many here do resort to that when they’ve exhausted all options and are unable to get more frequent treatment from a doctor.

However, it’s always preferable to try and get the correct treatment from a GP first (because it maintains access to supporting tests and enables onward referral to other specialists (often required with PA/B12 deficiency - and also to rule out other potential underlying cause for symptoms, if these continue.

Many here have had success getting the correct treatment by writing to their GP's (B12 treatment appeal) and including the relevant guidelines (many of which are sadly unknown to GP's).

In your case you could outline the tips I've included above (which your doctors don’t seem to be aware of) and focus on your concern that you are not receiving treatment for your neurological symptoms, as per the BSH Treatment Guidelines and BNF Prescribing guidelines (which I've included below) which could leave you at risk of irreversible neurological damage.

Also see the UKNEQAS B12 Treatment Alert in the links below. It instructs doctors to commence B12 treatment immediately if neurological symptoms are present - even if B12 levels are in the 'normal' reference range (and yours were well below).

Note: BNF guidelines refers to the treatment of PA. Whether you have PA or not is a moot point since the treatment for PA is treatment of the B12 deficiency it causes. You have proven B12 deficiency, so the treatment is the same as the treatment for PA. Your GP may have to read further down the BNF than usual - details of the neurological regime are the second or third paragraph.

If you do write to your GP (and I'd be tempted to write to the neurologist too - I expect you paid him a rather large sum) and don't get the right response (injections every other day until no further improvement - as per all the treatment guidelines for those with neurological symptoms), then people here can advise about safe suppliers of vitamin B12 etc.

Good luck with whatever you decide to do. Let us know how you get on and post again if you need anymore help.

Here come some links:


(BNF B12 Deficiency: Hydroxocobalamin Treatment Regimes)

pernicious-anaemia-society.... (PAS Symptom Checklist)

stichtingb12tekort.nl/weten... (BSH B12 Deficiency / PA Diagnostic Flowchart)

onlinelibrary.wiley.com/doi... in Haematology (BSH) Guidelines: Treatment of B12 Deficiency and Folate Disorders)

onlinelibrary.wiley.com/doi... (UKNEQAS B12 Treatment Alert, Neurological Symptoms and Risk of Subacute Combined Degeneration of the Spinal Cord – Immediate Treatment with B12 Injections)

stichtingb12tekort.nl/weten... (Problems with Serum B12 Test)

stichtingb12tekort.nl/weten... (Testing B12 During Treatment)

stichtingb12tekort.nl/weten... (Misconceptions About B12 Deficiency – Good to Know Before Seeing GP)

stichtingb12tekort.nl/weten... (B12 Deficiency: Neurological Symptoms Can Present Even When B12 is ‘In-Range’ and Without Macrocytosis (large red blood cells) or confirmed PA Diagnosis)

stichtingb12tekort.nl/weten... (B12 Deficiency and Intrinsic Factor – Can Be Negative and Still Have PA)



Thank you very much for your advice. I am constantly taken a back by how many times I have been given incorrect advice by Doctors on this matter.

I had read that I should be continuing the injections every second day for the neurological symptoms however I thought it would be unrealistic to get this. But I will now push my neurologist on this next time I see him.

I’ve cut ties with my GP on this issue as the last time I went I was called obsessive and that the only thing they could suggest was counselling.

All the other bloods I had done came back normal however I’m not sure if ferritin was tested. I will ask about this and in the mean time start on a multi vitamin maybe?

Thanks again for your advice. I definitely plan to speak to my neurologist again about more injections before I go down the shelf injecting route.

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Oh dear...another doctor who who thinks counselling is an acceptable way to deal with B12 deficiency. Another 'wheeze' we hear often is anxiety and depression...so many people offered antidepressant when what they actually need is treatment for B12 deficiency. Sad. And bad. Hope you've managed to find a better GP.

Good luck with the neurologist Elizabethrabbit...perhaps go along with some evidence from the links that you can share with him.

Take care and let us know how you get on 👍

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In answer to your question in the headline — yes I do think that you should start self- injecting . Treatment ASAP is paramount to prevent any irreversible symptoms . I had to do so myself . Just because your Intrinsic factor test came up negative does NOT mean that you don’t have PA. That happened to our chairman Martyn as well . S I is really cheap . Buying in bulk means an injection costs about £1.00 ( including ampoule , syringe, needles and swabs) B12 is NOT toxic in any way . I wasted too much valuable time fighting with GPs to get more than 1 injection every 3 months , at the same time feeling like death , with totally numb feet ( diagnosis was “ ideopathic “ ), I now self-inject weekly . My symptoms have gone , including my numb feet , but now they only burn , which I can put up with . I rest my case .

Don’t forget though that you need good amounts of folate , preferably as leafy green vegs peas etc . Failing that , take folic acid tablets (vitamin B9) . It works in tandem with B12 . Very best wishes to you .


Thank you very much for your reply. I think I plan to go back to my neurologist one more time in the hope I can get the injections every second day. If this is unsuccessful I will definitely be going down the self injection path. I am pleased to hear you had such an improvement! I too am suffering from numbness and didn’t know if the injections would help this.

I am ensuring I am eating a lot of vegetables to try and improve other levels and might consider a multivitamin too.

Thanks again for your advice

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You might need to inject daily to get rid of the numbness . It depends how long you have had it . I was worried about the numbness , as I would have had to give up driving if I hadn’t got rid of it . I have an acquaintance who was on omeprazole for 10 years ( stomach acid depressant ), which led to B12 deficiency resulting in numb feet . Totally misdiagnosed . After two operations on her spine , with no results, she had to give up driving , and is now in a wheel chair . The numbness is totally irreversible now.

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I am very new to this (just diagnosed B12- 148 in Sept of this year), and still trying to untangle the alphabet soup of deficiencies and causes. I did just receive my results from GeneSight's Combinatorial Pharmacogenomic Test, a mouth saliva swab test ordered by the psychiatrist at our local Behavioral/Mental Health Clinic (in USA) so he could figure out which anti-depressants may work best for me. (Which I probably won't take as the single B12 shot and supplements are starting to help with depression), I just wanted the test results- hahaha I had no clue what the tests were testing for and was surprised when finally after 6 weeks I got the results (which I got a copy of BEFORE my next appointment this Friday so I could research results and have intelligent questions to ask shrink) and found this gem along with what anti-depressants would work:

"This individual is heterozygous for C677T polymorphism in the MTHFR group. This genotype is associated with reduced folic acid metabolism, moderately decreased serum folate levels, and moderately increased homocysteine levels."

I recognized MTHFR as being important from other files posted to this group, but couldn't concentrate well enough to figure what all that was about. Now with my results and a few google searches it is all starting to make sense and that I need Folate supplements (preferably from food and NOT folic acid)! It also explains why I sometimes feel so yucky after eating pasta/grains/cereals that may have had folic acid added! Symptoms are also similar to B12 deficiency! Here are some good links I found. There are also links on this group that someone else can point you to about folate acid levels. I just used up all my brain energy for awhile. I hope this helps.





Many thanks for your reply. I will definitely have a look into this and mention it to my neurologist when I see him next.

Hope you start to feel better soon.

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Hi you have some great answers from people far more expert and knowledgeable than I. Just wanted to say don’t worry no need to panic. I have been in much the same state as you. I decided to cut out the middlemen ( the so called expert doctors). Unfortunately, the doctors can be extremely effective at doing more harm than good. Been self injecting for over a year now. Initially every day then tried every other. Been trying ever 3rd day for some weeks now, but just gone back to every other day, as have noticed a disimprovement. Will try every 3rd day again in 4 to 6 months, see how it goes. Hugely better than where I was 18 months ago but still a work in progress. Think if I had not taken responsibility for this (with the help and backing of a very supportive wife) I would be in a very much worse state by now. If you ever consider self injection, do not be afraid to try it, but be sure to keep to a diet that is high in folate, potassium, magnesium etc. All the right foods can be easily found on google. Bananas everyday helps with the potassium, which can take a big hit particularly in the early stages of self injection. Just research it a bit, ask questions on this site, all the info you need is easy to access.

Chin up and best luck



Thank you very much for your response. I am glad there are other people out there who feel as if they can’t go more than a few days without an injection!

Your response was very comforting as I constantly find myself saying surely this must all be caused by a serious disease and can’t just be a vitamin deficiency!

I will definitely have a look into these foods to ensure I am including them enough in my diet and hope that I get put back on my injections soon!

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