Pernicious Anaemia Society
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Hubby was diagnosed with VIT B12 deficient a few years ago and was having 12 weekly injections. After a blood test the GP said his levels were now too high and to stop the injections (as this could prove dangerous and damaging).

A year on and he is still not having the jabs, his bloodwork last week came back as 'within range' and he is exhausted, dizzy, and sleeps 12 hours. Diabetes is well controlled and bloodwork shows no reason for his tiredness.

I have read conflicting things about B12 jabs, that people should still be on them as they won't cause any damage and I'm concerned the GP has got it all wrong.

HELP please

14 Replies

Hi Sonjah70. Oh dear, you'd be surprised how often we hear of B12 injections being stopped, usually because of ill-informed GP's and the consequent lack of knowledge about the treatment of B12 deficiency and PA.

So first, just a couple of questions that will help people here to help you.

Has your husband being diagnosed with PA? Has he been tested for Anti-IF and parietal cell antibodies? Did his GP find a cause for his B12 deficiency?

Do you know what his current level of serum B12 is - and the reference range used? Doctors will often say this is 'normal' when it's bumping along at the bottom of the range and this is not good enough for someone with B12 deficiency).

Now to the issue of B12 being 'too high, dangerous and damaging'. Utter and absolute nonsense!!

Excuse me if I cut and paste from an earlier reply to someone else (to save time)...

If you look at the PAS pinned posts to the right of the page when you enter this site and open the third post down ('Stichting B12 Tekort') and scroll down to the 6th article, you will be able to read a scientific research paper which shows that B12 injections have proved safe for over 50 years: you cannot overdose and it is not dangerous. Perhaps this will reassure you 😀. Incidentally, all the PAS pinned posts are well worth a read and will give you the crucial basics about B12 deficiency and PA, together guidelines for treatment and diagnostic protocols.

The next thing to say is that all the guidelines say that it is the symptoms that should be treated, not the serum B12 levels. Your husband obviously has symptoms that sound like B12 deficiency, so he should be treated! All the guidelines state this (see NEQAS guidelines in the second PAS pinned post).

If the GP is making the assumption that he is not B12 deficient, then he should be investigationing your husband's symptoms to find a cause...and, of course, then treat that cause.

If your husband has previously been diagnosed with PA, then the injections are for life and should never be stopped. The treatment for B12 deficiency is the same treatment as for PA...B12 injections. A grey area arises when GP's don't look for the cause of B12 deficiency and mistakenly assume that because B12 levels have increased, then the patient must be 'fixed'.

This of course is nonsense, since B12 levels are automatically raised, sometimes to very high levels, when B12 is injected. The levels drop slowly over time, sometimes taking months or up to two years to drop below the reference range again. The fact that your husband is again having symptoms could be due to the slowly falling B12 levels.

Also - the level of B12 in the blood tells you nothing about what is happening to B12 at a cell level. Some people have high B12 levels in the blood but not much getting through to the cells - they are said to have a functional B12 deficiency.

So, in conclusion, your GP was wrong to simply stop the B12 injections. B12 is not dangerous or damaging. There is no such thing as a too high B12 level (unless you have never had B12 injections and the level is raised).

Anybody who has injected B12 will inevitable have high B12 levels - this is as it should be! Mine is always over 2000 and the highest I have seen reported here is 5999 (Martyn Hooper, chair of the PAS).

So, I suggest you read through the pinned posts, go back to your GP armed with the relevant guidelines, and try to get the B12 injections started again.

This might be tough since many GP's don't like being challenged by patients and are incredibly ill-informed about B12 deficiency!

Good luck and please do post again if you need further advice or support. Lots of people here to help, if needed.

Take care and I hope your husband gets his B12 and begins to feel much better very soon X


As well as all of Foggyme's excellent advice, you may want to join the PAS and enlist their help. Here's a recent blog by Martyn on the problem -

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Hi fbirder,

On Martyn Hooper's blog today he is talking about a new pill for people with NETs. A trial is planned and they are looking for patients.

Sounds very interesting and if it works at dissolving the ' little blighters' it would save people having to have scopes annually.

J 🍀

Ps; I know you have this condition fbirder,

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Thank you

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It is around 600 I believe. I will double check this. My husband is concerned at having a full dose tomorrow of B12 as he says should he not be having the starting doses again?


Hi sonjah70 just a few questions to add to Foggyme's comprehensive reply.

Do you remember why your husband was diagnosed with B12 Deficiency in the first place?

Do you know what his Folate level is?

What medication is he on for his diabetes?

Has he had gastric surgery,

What is his diet like - does he eat plenty of B12 containing meat, fish, eggs, dairy produce etc?

Does he use Proton Pump Inhibitors or antacids?

Does he have Crohn’s disease, irritable bowel syndrome, gluten enteropathy (celiac disease), or any other disease that cause malabsorption of nutrients?

Is he over sixty?

Has he a family history of pernicious anaemia?

Has he had surgeries or dental procedures involving nitrous oxide?

All (and more) can cause depletion of B12 so if you and your husband can "see him" in any of the above I suggest you list them and present them to his doctor as reasons why the injections should continue.

I am not a medically qualified person but I do know that it important to have a healthy level of Folate as this essential to process the B12.


First diagnosed about two to three years ago.

Metformon slow release for his diabetes and that is always well controlled.

No gastric surgery.

Diet is reasonable but was probably misinformed that the diet would not help.

He is on omeprazole.

No crowns or bowel disease.

He is 63 years old.

No family history that we know of but he has diabetes type 2, rheumatoid arthritis, fibromyalgia,

Dental procedures nitrous oxide no idea at all.

But thank you kindly for your reply and input. Just gives us more cause for concern that a GP would be allowed to make decsisions over something that they are maybe not qualified or knowledgable enough to comprehend. Will be making another appointment to go and see the GP.


You've hit four nails on the head with Metformin and Omeprazole and his age plus fibromyalgia can also put him at risk of B12 Deficiency.

Metformin and Omeprazole are both known to interfere with the absorption of B12 and as we grow older the stomach produces less acid with is needed to "grab" the B12 in food on its way down.


Just a quick addition...rheumatoid arthritis is an autoimmune condition. As autoimmune diseases tend to turn up in 'packs' (once you have one, you tend to get others), it might be a good idea to get tested for PA (anti-IF and parietal call antibodies (PAC), as PA can also be caused by autoimmunity.

But be aware, PA tests are only 50% accurate so it is still possible to have PA even if the tests are negative 😀.

Also a good idea to have thyroid function tested since many people with autoimmune disease also have thyroid issues (especially Hashimoto's thyroiditis) as there is a lot of cross-over in the symptoms of B12 deficiency and thyroiditis.

For thyroid tests, your GP will only want to test TSH but this is as unreliable as the serum B12 test and will not give the full thyroid picture. For this, you will need to be tested for TSH, FT4, FT3, anti-TPO and anti-TG. Hope your GP agrees to the tests.

Oh and, often GP's say tests ar normal when they are not since bumping along the bottom of a range (or indeed, the top) is often not good enough.

You are quite within your rights to ask for copies of all your blood results so if you want to get them and post the results here, people will be able to advise and comment 😀

Good luck x


Thank you all for your replies, most helpful. I am booking hubby in for B12 injection tomorrow although he is concerned should he have a normal dose or go back to the starting doses again. His level is around 600 but the symptoms are quite profound. Thank you


Are you a member of the PAS(Pernicious Anaemia society)?


They are helpful and sympathetic and in some cases can intervene on behalf of members.

PAS tel no 01656 769 717

Blog entries on Martyn Hooper's blog that may be relevant. Martyn Hooper is the chair of the PAS.

Have a look at the pinned posts on this forum, lots of info about b12.

I found the summary of b12 documents fbirder compiled useful. Link to his summary in third pinned post and on his profile page. Lots of quotes from b12 documents/articles that might help if faced with a medic who does not understand B12 deficiency.

I would also suggest googling and reading "BCSH Cobalamin and Folate Guidelines".Page 29 is a diagnosis flowchart that outlines the process GPs should follow in UK with someone who has b12 deficiency. Page 8 gives details of UK B12 treatment. On another page, it basically says that testing b12 after supplementation has started is irrelevant. Some GPs may not have read this document. I gave a copy of this document to my GPs.

B12 books

"What You Need to Know About Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn hooper. Up to date with current UK guidelines.

"Could it Be b12" by Sally Pacholok and JJ. Stuart. Very comprehensive book about B12 deficiency.

Link about writing to Gp if unhappy with treatment. Does not seem to mention BCSH Cobalamin Guidelines which I would if I had to write to GPs. The person who runs the website can be contacted by e-mail.

As Foggyme says the IFA test is not always reliable. it is possible to have PA even if IFA test negative. The BCSH Cobalamin and Folate guidelines mention Antibody Negative PA on page 29 and elsewhere in document.

Testy Results/Medical Records

I always get copies of my blood tests now as in past I was told everything was normal and I found abnormal results on copies. In relation to b12, I look particularly at B12, folate , ferritin and full blood count.

Some people get a complete set of their medical records. Can be expensive but interesting to see what has been written in past. There have been people who found out that they were diagnosed with PA in past but were not told at time. Some surgeries have online access to a summary of records/test results but this will not necessarily have all the info.

Causes of b12 deficiency

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

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Don't forget the thyroid testing - like the pancreas it is all part of the Endocrine system. I read recently that diabetics should have their thyrouds checked - correctly that is 😊


I don't know if it is exactly the same in all areas but, after filling in a form from the surgery I have permanent on line access to most of my records via an option within the appointment system. I can fetch blood test results with graphs over time, most snail mail letters, vaccination record. and there is an option to print. Since nothing will persuade the local system to send me the copy GP letters I should get this is useful. My rheumy was pleased I was able to send her blood test results as one half of my county does not speak to the other.


Have his RDW ( red blood cell distribution width checked , if its above 14% then his vitb12 could affected , vitb12 should not be below 141ng/ nl though testing shortly after receiving injections won't help , hope this helps .


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