Pernicious Anaemia Society
16,347 members11,364 posts

Soooo confused!

Hi everyone

Hoping someone can clear this up for me.

I suffer from various illnesses, fibromyalgia, scoliosis, arthritis, trigeminal neuralgia, restless legs anxiety and depression. But most recently the neurologist arranged bloods for my vitamin b12 levels. These came back as 81 ng/L (normal range 145-914) with a serum folate reading of 2.67 ug/L (normal range 3-20). So she referred me back to the GP requesting he start me on supplements.

The GP told me to book b12 injections with the nurse which I did. She told me it would be 2 injections for 3 weeks then once every 3 months. However once I had 3 injections the GP requested more bloods. Which at the time the nurse said it was pointless as my b12 would show as a high level due to the boosters I was having. We did it anyway.

Today I had the last of the 6 booster injections. And my blood results came back which left the nurse asking me who started me on the injections in the first place as my reading was now 1500! She said she wouldn’t have thought it would have gone up that much. And now on my notes the GP wants to see me which I assume is probably to say I don’t have low B12. So I’m just confused as now the nurse is saying I prob won’t have anymore injections. Sorry for the long post. Has anyone had anything like this before?

Thanks for reading!

16 Replies

Oh good grief, what do these surgery staff know about B12?!

Once you'd had injections, OF COURSE your bloods would be high. I'm surprised they weren't higher! My GP requested the same repeat test, and the lab wrote back that it was pointless to test once you'd started injections. Your initial test was really low, you needed the jabs, and you will need more to 'top up' in future. Print some of the pinned posts on this site and take them in to your GP at your appointment.

Looking at some of your other diagnoses, it's possible that some of your symptoms may have been to do with B12 all along. Read up on some of the symptoms low B12 causes - sounds like your system was desperate for B12!

Lots of luck x


Thank you for your reply. Yes she said at the time it was pointless and then alongside another nurse today contradicted herself. I have so many symptoms that I finally felt like I was getting somewhere and that these injections would help with my fatigue and pain etc. Thought it would be the answer to my prayers but now sounds as thou it could be taken away due to the Surgery not being knowledgable enough on B12 x


In general levels would be off the top of the measurable scale just after an injection or loading doses - the B12 gets into your blood very quickly from an intra-muscular injection.

Most of it then gets removed - half in about 24-48 hours but it does vary a lot from individual to individual, and then it will gradually fall over time - though how quickly depends on a number of factors.

Serum B12 is rather irrelevant after loading injections and contrary to the nurse I would say that your results were actually quite low for someone receiving loading injections. The effect of B12 isn't caused by the amount of your blood but by the amount in your cells. Amount in your blood is a reasonable proxy measure if you haven't had injections but if you have had injections that introduces a number of factors that mean normal range just doesn't apply as a way of gauging if you are okay. Unfortunately most GPs are unaware of this (most of which is common sense and a very basic understanding of how the injections work but ...).

If you have neurological symptoms the loading regime should actually be loading shots 3xweekly until symptoms stop improving followed by maintenance doses every 2 months though if the results above are anything to go by I seriously doubt that that is going to be enough for you.


Hi Thank you for your reply. I was under the neurologist for trigeminal neuralgia and now she’s referred me back to the GP to control.

I appreciate all the info. Even had me doubting that maybe the first blood test was incorrect! I am yet to really notice a major difference and the nurses today made it sound as thou I should be bouncing off the walls!


people react very differently. I didn't really notice any difference until my 2nd maintenance shot ... though on reflection treatment did make me a lot worse until I worked out that I really needed a lot more B12 and levels off the scale to function post loading shots - not everyone needs really high levels after loading shots but it seems to be quite a high proportion of people.


Hi Carlie4987

You were deficient in both Vitamin B12 and Folate and as Gambit62 said according to the N.I.C.E guidelines loading doses should "continue until there is no further improvement" in neurological symptoms so one option would be to list them and go back to your doctor asking for the injections to continue.

Click on the above link, then on "Scenario: Management" and scroll down.

It would be good if your nurses could look up the guidelines for themselves.

Were you actually prescribed folic acid? If so what strength and for how long?

Replacing B12 will lead to a huge increase in the production of blood cells and platelets (which occurs in the bone marrow) and can lead to rapid depletion of folate and iron stores; this can then limit the expected recovery of Haemoglobin. Both iron and folate may be needed.

I am not a medically trained person but I've had Pernicious Anemia (a form of B12 deficiency) for more than 46 years.

I wish you well.



Thank you so much for your reply. I will take a look now.

No I wasn’t given anything for folate levels Cos they said the b12 injections should boost those anyway? It’s all new to me and when u don’t really know enough yourself your expected to trust what doctors/nurses tell you.



What a great informative site. Thank you. I will def be taking that info along to my appointment

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What a strange thing to say about Folate levels "b12 injections should boost those anyway" - Folic acid works closely with vitamin B12 in making red blood cells and helps iron function properly in the body - it is not produced by having B12 injected,

Actually Carlie4987 your "medical team" may "accidentally" have saved you a lot of "agony" by not prescribing folic acid before giving you the B12 injections.


Giving Folate to a B12 deficient person without B12 can lead to an irreversible exacerbation in neurological features

Care should be taken not to give folic acid (instead of B12) to any patient who is B12-deprived, as this may result in fulminant neurological deficit.

Click on Management

The British National Formulary (Section 9.1.2 Drugs used in megaloblastic anaemias) states

Folic acid has few indications for long-term therapy since most causes of folate deficiency are self-limiting or will yield to a short course of treatment. It should not be used in undiagnosed megaloblastic anaemia unless vitamin B12 is administered concurrently otherwise neuropathy may be precipitated.

Type (Section 9.1.2 Drugs used in megaloblastic anaemias) into the search box and scroll down to "Folic acid". Your doctor should have a copy of the British National Formulary on his desk.

Take care now.


I second all that has been said above and would like to add that as I started to read your list of diagnoses I was wondering "low B12, low folate" and would hope that with enough B12 and supporting supplements you will get a significant improvement in your comfort levels in time - and you may well find improvements for years to come.

The difficulty is getting enough B12 and folate from the Drs and they are even worse with other things you may need!

For the extra B12 to work properly your body will need a wide range of vitamins and minerals and many people benefit from taking a broad spectrum multivitamin and mineral supplement plus extra folate, potassium, magnesium and iron as well as making sure they have a diet rich in protein, providing all amino acids.

I suggest that you Google these to see what foods are rich in these that you may like.

Often blood tests results are not the whole story as, as Gambit says, it is also how the cells take up the nutrients that matters too - so sometimes you will find that you feel better when supplementing, even if your serum levels are fairly OK.

There are quite a lot of us who need more B12 than the NHS will supply and we buy our own supplies and self inject (SI). There are also many options available if you have other complications and huge amounts of fantastic help on here!

Good luck with everything and welcome to our community.


Hi Carlie4978 in feb 2017 my b12 was 93 I was really ill I took the advice give on this site and my health has really improved I decided to self inject every other day until no further improvement.


It makes me very proud how members come in to help new members, well done all Xx Carlie4978 you are in good hands here, just remains for you to take all the info and knowledge on board and start being the manager of your care programme as unfortunately most consultants, doctors and nurses just do not know and give out misleading advice. Xx


I am so grateful for everyone’s comments and advice. U have made me feel very welcome. I have never posted anything before in groups and now I really don’t know why ?! You are all so kind for helping me understand the diagnosis and helping me move forward.

Thank u all x


Have you read the book The Magnesium Miracle by Carolyn Dean. Many of your health issues could, and probably are, being caused/ made worse by magnesium deficiency. Even if you are taking magnesium it might not be being absorbed/ assimilated. Magnesium deficiency symptoms can be so varied in each of us. B12 helped me cope with magnesium deficiency symptoms but never actually fixed the symptoms like magnesium has. Also I had the long health issues journey of having to discover to stop having soymilk every day to allow magnesium to work properly in my body.

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I would second that.

B12 and magensium were life changing. I had all the symptoms you have Carlie and they all but disappeared.

However I am also hypothyroid and that can overlap with a lot of symptoms too.’so it may be worth checking thyroid tests also if no improvement. (And vit D!)

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Sorry haven’t read your replies so you might have already have had same answers.

Your B12 was very low, after an injection it shows up very high so blood test and numbers after injections don’t mean anything.

They’re obviously going to be high (sometimes very high).

You’ve had six injections so don’t the nurse and doctor know levels will show up high !......That is normal. My levels after injections were 2000 or 3000 (I’m not sure but one of the two).

Point is no point having blood test to check B12 levels after injecting B12. Nurse is wrong and she don’t know, she’s not a Dr.

Dr is also wrong as he needs to treat your symptoms and not look at your levels after giving you “loading doses”’s obviously going to be high. Your treatment needs to carry on with B12.

Your Folate is also low which should be taken daily when on B12. Makes a huge difference.

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