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Pernicious Anaemia Society
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Too high b12 level!?

I had a b12 level of 182 three years ago. Had lots of b12 deficiency symptoms. Had injections for three years roughly. Feel much better.

I've had blood tests done, but always just after my injection and my level is above 2000.

The doctor seems to think I don't need them anymore and I will need more tests.

Surely just after an injection it would be this high??

10 Replies


Re:"Surely just after an injection it would be this high??", yes, it would be better to have bloods taken before you are due your jab. But its not only about serum B12 levels, its also about how you feel, symptoms count as much as numbers.

Kind regards,


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My doctor has told me to have bloods done when I'm due my next injection. I'm worried that my injections won't be every 3 months if the levels are still high. I struggle when I'm due!

Maybe I will have to pay for an active b12 test.

Thanks for reply.


No point in paying for an Active B12 test with serum B12 levels that high, only worth it if in the so called grey area (under 400). Other things should be tested if you are not doing well on current treatment, things like serum folate (very common to become also folate def once B12 treatment has started, all B vitamins, particularly B12, folate and B 6, but also other minerals such as iron etc need each other, giving loads of one and not enough of the other just does not help). Also nearly 50% of people with PA develop hypo thyroid and visa versa so testing thyroid function (and possibly thyroid antibodies etc is useful.

There is Just no pint in doing an active B12 test with your results and being on B12 treatment.


extract from NICE guidance

Ongoing monitoring of people being treated with vitamin B12 or folic acid is generally considered unnecessary (unless a lack of compliance with folate treatment is suspected, or anaemia recurs).


This is because, unless you know that your original deficiency was down to diet (absolutely no animal products or supplementation with fortified cereals) then the original B12 deficiency you were being treated for was caused by a malabsorption problem.

The B12 shots you have received are keeping your B12 levels close to what you need but if the stop then the malabsorption will take over again and you will become deficient again.

It is possible that your results just before your tests might still come back high - because the test is looking at all the B12 in your system and not just at the form that you use ... and it certainly isn't giving any indication of what is happening at a cellular level - but that still wouldn't mean that you are getting enough B12.

Once you have started treatement a low result would be significant but a high result means absolutely nothing.

The basis for the recommendation references the possibility of deficiency recurring - it makes no reference to high levels because high levels are not a problem.

I had a blood test in December - booked after speaking to my GP which was after I'd taken my morning dose of methyl B12 (2.5mg nasally) - result came out as >2000 but was marked 'no action' by the lab ... so didn't have to have any discussion with people about not being able to overdose on B12 which was positive.

Really hope that you can get through to your GP


Thanks for reply.

Unfortunately every gp i have had doesn't seem to read any of the guidelines. If I ague with them about it they tell me they are the doctor.

This has really upset me and put me back to the beginning when I had to fight to even get the injections.

At a loss where to go from here. I would pay for private treatment, but not sure who I need to see.

Just wish some gp's would get the illness to see how Ill it can make you. Then we might get better treatment.


Is there a local patients group that you could raise the attitude with?

Sorry that the GPs your dealing with are so poor on people skills if that is how they are behaving.

B12 isn't toxic so there is always the option of treating yourself.

Subcutaneous injection - not as efficient as intramuscular - is quite easy to do ... and if you can get someone to show you how to do intramuscular then that's good but there are other options - I find nasal spray works really well for me and to be honest I only go back for loading shots to keep things on my medical records ... and think I'm probably due a maintenance shot soon :)

You can import B12 from other parts of the EU where injectable isn't a prescription only medication just because it is injectible. It isn't that expensive - one ampoule costs less than £1


Where did you get the nasal spray from.?

I think doctors are being told to try and cut patients injections down to cut costs.


I get mine from detox people


My wife just had her B12 Serum Test and after ajab was >2000 and Folate was 20. She still has the aches and pains and Doctor say's B12 is high.

I can private Injections in London for £55 without Doctors referral - Just Google B12 Injections London

I am very concerned about the position and have asked Doctor to carry out Thyroid tests and to look at why Serum B12 is so high at >2000 and Folate at 20 - Why is the body not utilising the B12 in the blood?


Ever since I first became deficient with b12 I have never felt back to normal even after 3 monthly injections.

I don't know why. The doctor can't see anything else on my blood tests and I've had brain scans, and all sorts of tests.

It's a strange illness as doctors seem to think if your levels are high you are fixed!

I think my problem is I was left to long trying to get the injections that I have permanent damage to my balance.

Thanks for the advice on the private jabs.

How long after an injection was your wife's level checked?


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