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Pernicious Anaemia Society
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B12 injection query

I went for my 8 weekly B12 injection today, a few days early due to holiday when next one was due.

The nurse said I was not due one and anyway B12 injections should be every 12 weeks.

We moved last year and my previous GP prescribed 8 weekly. When I moved here, I continued with 8 weekly injections with a three month break when I tried the tablets. I also have Coeliac disease and underactive thyroid. The tablets didn't agree with me and so was allowed to revert to injections.

I now have to have a blood test before I have the next injection and they will decide if I am allowed to have 8 weekly injections.

My previous GP agreed with the expert info on the PA site that 'normal' test results are not the same for everyone. Also different parts of the country have different criteria.

I've been having 8 weekly injections for about 3 years now so why the change?

My previous GP said that having the 8 weekly injections would do no harm but today I was told you can have too much. Anyone any ideas?

26 Replies

Ask the person who advised that you can have too much to put it in writing along with the research they used to provide the advice.

Both doctors and nurses are supposed to carry out research based practice at all times.

I wish someone like the PAS would do an accredited e-learning course that professionals could use as part of their continual professional development to bring them up to date.

My GP told me that he knew everything about b12 as he studied it as part of his training.

He's a clever man but he's been a doctor for a very long time.

That's worrying.


I just get a little bit miffed about the conflicting advice. They didn't really like me reverting to injections. I feel like a nuisance when I have to go for my injection.


Don't feel a nuisance, that's what they are there for, and a lot of them are paid a good salary and not doing their job properly.


The PAS do, indeed, provide just that - an e-learning course that can earn them CPD points.



Do you have a link?


Yup. I edited the link in while you was typing.

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Just done it. It's not very impressive sadly.

What's needed are a series of short videos dispelling the myths, with questions.

The one you link to is just reading the guidance the a few simple questions.

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To Steap - He may be clever but sounds a 'big head'. A GP I know said that 'Vitamins' were about an hour on a Friday afternoon in their second year. Luckily for me he has updated himself.

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Unfortunately knowledge of B12 and how it works tends to be extremely low - there are a lot of myths and ... sorry you are caught up in it.

8 weeks is not going to harm you - recommended treatment for cyanide poisoning is 5g hydroxo-B12 administered intravenously with follow on dose after 30 min if needed. That is more B12 in an hour than you are going to get in a life-time of 8 weekly maintenance shots.

Having coeliacs means the problem is absorption related and even high dose oral is unlikely to be effective.

Sounds like you had a GP who was reasonably aware of B12 but the new one is far from being up to speed.

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Ithanks for that. It was the nurse who said she couldn't give me the injection today, she had to get permission from a doctor. She did get the go ahead but I have a feeling that they will only give 12 weekly after today. Probably another NHS cut without understanding the effect it has on patients.

My previous GP was an absolute star, I never felt as though I was a problem. A bit different with this new practice. They have already stopped items I had previously on repeat prescription for long standing issues. Items I can't buy from the pharmacy.

They are stopping GF food on prescription as they believe it is 'readily available in the shops'. They should live where I do! Again cutting without understanding or experiencing the disease or the problems we have.


I thought that they were still doing GF food on prescription, but a much reduced range. Bread and pasta in; cakes and biscuits out.


When I registered with new doc, I was told if I needed flour I would have to make a request and they would consider it. It is no longer on my repeat prescriptions. That was last April and things have changed since then.


There are hundreds if not thousands of us who inject every day, some of whom have been doing so for decades and many others who have to have 2 injections per day.

clivealive on here is nowhere near as extreme as that but see his posts for some real inspiration and to see how wrong their suggestions are.

I have now done nearly 600 x 1.5 mg in 1 ml hydroxocobalamin daily injections and take all the supporting supplements I need to make it work. I am better beyond what I could have imagined when I started and am still improving.

If you need it you need it! Not getting enough causes damage which in time gets worse and can become irreversible.

Good luck with sorting it out!

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Thanks for that. I was so angry yesterday, it's good to hear that my previous GP was right.


It's maddening, isn't it! It's all so easy for them when it's your life, not theirs!

If you get a moment it's worth Googling "Recovering from Gaslighting" to see why their dismissive treatment feels SO horrible!

Good luck!

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I'm still mad with my NHS GP's dating from Jan. 2016. How can they be so obtuse. I just looked up 'obtuse' s exact meaning, (why I don't know)

"- not quick or alert in perception, feeling, or intellect; not sensitive or observant; dull."

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please don't feel you are being a nuisance.

"nurse said I was not due one and anyway B12 injections should be every 12 weeks"

In UK b12 injections should be every 8 weeks if patient has B12 deficiency with neuro symptoms.

Perhaps nurse could look in GPs copy of BNF to check?At some point I'm going to get my own copy.

BNF B12 info below


Same info is in BSH Cobalamin and Folate Guidelines, about a quarter through document. I take a copy of this document with me to appts sometimes.


Same info again in NICE


Do you have neuro symptoms?

pernicious-anaemia-society.... see Symptoms Checklist


"I now have to have a blood test before I have the next injection"

Think that BSH Cobalamin and Folate Guidelines mention that retesting of b12 levels is irrelevant after b12 treatment has started.

fbirder 's summary in third pinned post has lots of useful quotes from B12 documents, including some relating to retesting b12 levels.

I am not a medic just a person who has struggled to get a diagnosis.

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It worries me that the nurse believes that you can have too much B12.

It took 30 years for me to get the Coeliac diagnosis and almost as long for the thyroid diagnosis. Admittedly I didn't realise that the symptoms were thyroid problems until Google arrived. I then had a partial thyroidectomy when I had a cyst on it. I had blood tests following that but they always came back 'borderline'. Ten years after the op I was prescribed thyroxine.

Will wait and see what happens after my next blood test.


Hi Polly,

Do you have a diagnosis of PA (Pernicious Anaemia)?

As you already have two auto-immune diseases then the possibility of other auto-immune diseases increases (and PA is auto-immune).

Have you ever had an IFA (Intrinsic Factor Antibody) test? This can help to diagnose PA but IFA test is not always reliable and it is still possible to have pA if IFA results are negative( called Antibody Negative PA).

The reason I'm asking is that sometimes forum members have had injections stopped when B12 levels have been retested and found to be high. Treatment for PA is lifelong injections. There are other causes of B12 deficiency that require lifelong treatment.

Hopefully this will not happen to you but come back to forum for support if it does.

In UK people with b12 deficiency with neuro symptoms are supposed to get a loading injection every other day for as long as symptoms get better (could mean loading injections for weeks even months) then an injection every 2 months/8 weeks

Some UK people with B12 deficiency with neuro symptoms, on forum, whose doctors try to put them on standard B12 treatment (injections every 12 weeks) have found it helpful to write letters to GP. See link underneath.


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I don't remember having the IFA test, but I will ask if I can have it done.

I had the five loading injections over about ten days when I was first diagnosed with B12 deficiency. I was told that injections were for life but that was about all the info I was given. I then had 12 weekly but GP agreed to change to 8 weekly when I felt the symptoms showing again by 7/8 weeks.

I do have pins & needles in my toes, not sure if that is neuro.

At least I now have info to take when I go for my blood test.



Pins and needles is normally considered to be a neuro symptom, tingling is mentioned on PAS Symptoms Checklist.


IFA test

Be aware that if IFA test comes back negative, it's possible GP may consider stopping B12 injections. If this happens you could show them info on Antibody Negative PA, see link below.


"told that injections were for life but that was about all the info I was given"

The fact that you were told injections were for life when first diagnosed suggests to me that GP thought you had PA or another long term absorption problem.

"I had the five loading injections over about ten days when I was first diagnosed with B12 deficiency"

Not sure why you only had 5 loading injections as BNF (British National Formulary) Chapter 9 Section 1.2 states six loading doses over 2 weeks and a patient with b12 deficiency with neuro symptoms is supposed to have loading injections every other day for as long as symptoms get better.

This suggests to me that it's possible your GPs are following local NHS B12 deficiency guidelines. Some of these local guidelines have not been updated for several years and some differ in some details from advice in BSH Cobalamin guidelines, BNF etc.

Might be worth trying to track down local B12 guidelines as it might explain nurse's comments.

Local NHS B12 Deficiency guidelines might be found

1) By internet search

2) Search on local NHS website, possible under haematology policies/guidelines

3) FOI (Freedom of Information) request to local NHS website.

4) Your local CCG, if in England, may be able to tell you what B12 deficiency guidelines are being used in your area.


5) Request to GP practice manager asking what B12 guidelines practice is using. Warning.....This may irritate them.

6) If all else fails, then local MP may be able to help .MPs can be very useful in getting answers from officials who are unable to answer members of the public.

Causes of B12 deficiency


Have you ever got a copy of your medical records?

Would cost about £50 plus. It's possible that there may be something in there that confirms PA. Who diagnosed you with B12 deficiency? If it was a hospital consultant, there may be a letter from hospital to GP. Or maybe a letter from GP to haematologist asking for advice.




Other sources of B12 info

1) Pinned posts on this forum

2) BMJ b12 article

My GPs showed some interest in this. Think GPs trust BMJ articles.


3) PAS (Pernicious Anaemia Society) website


PAS tel no +44 (0)1656 769 717 answerphone so messages can be left

Martyn Hooper's blog


4) B12 deficiency Info website

Lots of B12 info and an interesting blog


5) b12d.org


6) Book "What You Need to Know About Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper. Martyn is the chair of PAS. Book is up to date with UK B12 guidelines.

7) Book "Could it Be b12" by Sally Pacholok and JJ. Stuart (USA authors)

Very comprehensive book about B12 deficiency


Many thanks for the info I will work my way through it.


B-12 Is Non-toxic...What Your Body Doesn't Use Your Body Gets Rid Of...Change Doctors...Your Levels Should Be Checked Monthly At The Least...They're Suspecting I Have Pernicious Anemia So The Only Way My Levels Stay Normal I Require Injections...Have Them Run Labs To Check Your Red Blood Cells...Palatial...My Cells Are Oval Shaped...Equivalent To Someone With Sickle Cell Anemia...My Levels Were So Low That I Ended Up With BCC Skin Cancer...& Had To Have Mohs Surgery (Nose)...I Advocate For Myself...When I Went To The Dermatologist They Asked If My B-12 Levels Were Low...There Are 100 Different Autoimmune Diseases...Usually If You Have One You Have At Least Three...

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I have underactive thyroid & Coeliac disease too. Apart from an annual blood test to check, that is the only monitoring I have.


Doctors Aren't Very Well Versed...It's Like A Mystery To Them...The Specialist You Can See Are...Rheumatologist, Neurologist, Endrocrinologist, Gastroentrologist & Hemotologist...So There's No Wonder It's Difficult To Get Proper Treatment...You Should See A Gastroentrologist & A Endrocrinologist.

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I saw a gastroenterologist a couple of times after I was diagnosed with Coeliac disease but that was 10 years ago. Have never seen any of the others.


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