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Pernicious Anaemia Society
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Is it unreasonable to ask for another injection?

Hi, my situation is that after finding out my b12 was 68 I had 5 loading doses 6 months ago. After going back to the doctors because I could barely function due to my symptoms they told me my b12 was normal - it was 199.

I persuaded the doctor to give me another injection, this alleviated some of my tiredness but a week later I am still very foggy and having troubling concentrating. I have to return to university in less than a week and I am worried about conducting my studies with these symptoms. Therefore I requested another jab but was told I wasn't allowed. The gp said they didn't want to overdose me and it would be breaking protocol to just give me another jab because I asked for it since they'd already given me one when my levels were 'normal'.

Am I being unreasonable wanting another jab so badly? I'm worried and getting quite angry with my gp! Should I push for another?

Also, on a side note, is it normal for b12 levels to be about 700 one month after loading doses? Someone told me this was quite low for so soon after a set of loading injections.


9 Replies

No you aren't being unreasonable - you are just facing a wall of ignorance where B12 deficiency is concerned.

Treatment should not be based on serum test results - particularly after you have received loading shots.

Serum B12 is a rather blunt instrument and cannot be interpreted without looking at symptoms as the amount in your blood is not a good guide to what is going on in cells. Also people vary very much in the levels that they need to ensure that enough is getting through to cells - going by ranges that are based on statistical averages without bearing in mind that people are not statistics is bad science and even worse medicine ... but unfortunately far from uncommon.

People also vary very much in how long it takes for B12 to be removed from their blood - and 700 just 1 month after loading doses does imply that you are at the 'efficient end' for your kidneys filtering out B12 so need it much more frequently than you have been prescribed.

Unfortunately injectable B12 has only been licensed in the UK for a frequency of every 2 months - which is just a quirk of the way licenses are given. GPs are able to use their discretion on treatment but the license does tend to make them rather jittery about any more frequently than 2 months which is a huge pity as it isn't dangerous and for many would be life-saving.

Please - read through the materials in the pinned posts - especially those produced by fbirder and draw these to the attention of your GP. Please also join the PAS - as they may be able to get through to your GP if quoting materials such as the BCSH guidelines at your GP doesn't work.

The guidelines are quite clear that B12 treatment is for life and that there should be regular maintenance shots (at least every 3 months) unless it is proven that the original deficiency was caused by lack of B12 in your diet (which is very very unlikely unless you ate next to no meat/fish/dairy and had no supplementation, and even then it is just unlikely unless you actually had no meat/fish/dairy and never touched a fortified breakfast cereal). Your description of symptoms implies neurological involvement in which case the correct regime would have been shots every other day until your symptoms stopped improving followed by maintenance doses every 2 months (though given the way your levels plummet even that is unlikely to be sufficient)

Please also read this blog



This was very helpful thank you, I ended up buying own for a second injection x


Hi Bodley I am so sorry you are having to struggle so hard to get the treatment you need.

Do you know why you were so B12 deficient six months ago and do you know whether your Folate level was tested as this is essential to process the B12?

As Gambit62 says there are many reason for B12 deficiency and it might help with your "arguments" with your doctor if you could identify yourself in the following list.

Vegetarians, vegans and people eating macrobiotic diets.

People who’ve undergone any gastric and/or intestinal surgery, including bariatric surgery for weight loss purposes (Gastric bypass).

People who regularly use proton-pump- inhibitors. H2 blockers, antacids, Metformin, and related diabetes drugs, or other medications including the contraceptive pill that can interfere with B12 absorption.

People who undergo surgeries or dental procedures involving nitrous oxide, or who use the drug recreationally.

People with a history of eating disorders (anorexia or bulimia).

People with a history of alcoholism.

People with a family history of pernicious anaemia.

People diagnosed with anaemia (including iron deficiency anaemia, sickle cell anaemia and thalassaemia).

People with Crohn’s disease, irritable bowel syndrome, gluten enteropathy (celiac disease), or any other disease that cause malabsorption of nutrients.

People with autoimmune disorders (especially thyroid disorders such as Hashimoto’s thyroiditis and Grave’s disease) Type 1 diabetes, vitiligo, lupus, Addison’s disease, ulcerative colitis, infertility, acquired agammaglobulinemia, or a family history of these disorders.

Women with a history of infertility or multiple miscarriages.

Infants born to and/or breast fed by women who are symptomatic or are at risk for B12 deficiency.

I'm not a medically qualified person but there are others on here like Gambit who will be able to give you good advice.

I wish you well for the future.


Thank you for your advice. My folate level was 19.8 ug/L so normal i think.


Hi littledos,

I can't add much more helpful info than what Gambit62 & Clivealive wrote, except your doctor is very ill informed about B12! He's an idiot, in fact. I am angry on your behalf. I get upset when there is a ready, inexpensive solution to the problem-more B12- and it is so hard for people to get it from their GP's!

That is why so many folks on this forum chose to self inject. You can order from Germany. If you don't have luck with your doctor, you might consider self injecting. People in this forum can walk you through it.

I'm in the US, can't get it from Germany, so I can't advise on that.

Good luck!


oh no - not another gp taking about overdose and protocol.... read a lot of messages posted about this!

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Definitely not unreasonable little dos! As others have already mentioned, your test result was VERY low and B12 injections should have been every other day until no further improvement as per BNF guidelines to prevent your neurological symptoms becoming worse.

You could write to GP with the following latest BMJ research document (page 4) :


Under: How is response to treatment assessed?

"Cobalamin and holotranscobalamin levels are not helpful because they increase with vitamin B12 influx regardless of the effectiveness of treatment, and retesting is not normally required."

Under: Parenteral treatment

"Standard initial treatment for patients without neurological involvement is 1000 μg intramuscularly three times a week for two weeks. If there are neurological symptoms then 1000 μg intramuscularly on alternate days should be continued for up to three weeks or until there is no further improvement.4 25 In irreversible cases, for example, pernicious anaemia, the treatment should be continued for life."


You may also find the information in the following link helpful in deciding what to do next. If GP is still unco-operative, I would contact the PA Society to support your case, as urgent and sufficient B12 is essential to having a healthy life.



Thank you very much. Since your reply I have indeed to written to my doctor. I ended up buying my own b12 to inject so I could come back to university. My new doctor is more cooperative thankfully! x


That's such good news littledos - I'm so glad you took matters into your hands and are now are well enough to attend university 🤗

Very best wishes to you.

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