More B12 maybe : So I started with the... - Pernicious Anaemi...

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More B12 maybe


So I started with the injections over 8 months ago and I feel that the last injection will not get me through until the next one, I get them every 3 months, but I'm already starting to get the headaches and more muscles are twitching, so do I ask my doctor for another blood test to see if it's getting absorbed properly, hopefully someone might have some advice, thanks

6 Replies

A blood test will almost certainly show high levels of B12, so will be fairly pointless.

If you’re getting neurological symptoms then the BNF says you should be on 8-weekly injections.

Cb1963 in reply to fbirder

Thanks, I suffer with pn, but I have had numerous stomach problems over the years and I'm on life time omeprazole, and I know this interferes with absorption issues, but it's the start of the headaches is going to be a problem, absolutely crushing, so I'll follow up with the doctor next week, thank you for getting back to me, ta

Good luck! you will find tons of good advice here. I strongly recommend taking control and doing what your own body wants. 3 monthly or 2 monthly just may not be enough.

I inject when I feel I need it -- which varies from every 6 weeks to twice a week. What I need seems to depend on stress and physical activity. I aim only to inject when I need to and to listen to my body. I couldn't survive on once every 3 months.I started on that. I can end up unable to stand after a week, esp if stressed. Sometimes I'm fine for 3 months. The difference the injection makes is like a miracle. (I also take folate and D3 daily). I benefit hugely from being in charge, highly recommend it. doctors are mostly confused and over-cautious about a drug which is harmless....

(Another CB from 1963...)

Cb1963 in reply to Mashie44

Thanks for the reply, yep I think it was roughly two after I had the injection that I already feel like the zip had disappeared, and it seems to much of a coincidence that the headaches started at the same time, I dunno about you but I feel that these injections can be overlooked by the medical professionals and I've not had any sort of follow up, I would of thought a blood test in between injections would see if everything is in normal range,, I always wondered if these levels are all the same around the UK or does it differ with each medical practice, thanks again for the information.

Mashie44 in reply to Cb1963

The medical profession mostly don't know much, you're right to question it. The only way until they do is to read, experiment (it isn't dangerous if you learn about what you are doing when you self-medicate). This forum helped me tons. good luck!

FoggymeAdministrator in reply to Cb1963

Hi Cb1963. Just a quick comment...all the guidelines state that it is not necessary to test serum B12 levels following the commencement of injections - unless checking for low levels. The 'normal' reference range no longer applies since a) B12 levels tell you nothing about the efficacy of treatment and b) levels are astronomically high following injection, then fall until the next injection - so all that's being measured is how much B12 has been injected, metabolised and excreted. So this is an entirely different mechaism than the one at work when B12 is obtain via diet and drawn down from the liver.

It’s worth noting that when on injections, B12 levels are expected to be much higher than the 'normal' reference range - mine are always over 2000 and we've seen them as high as 5999 (as high as the test would measure). GPs often stop B12 injections or reduce the frequency if they test and find that B12 is within the normal reference range - this is wrong.

So, following the commencement of injections, monitoring symptoms (not serum B12 levels) is what's important - if symptoms come back before the next injection and are alleviated when the next jab is given, then that’s a sure indicator that more frequent injections are needed - though if a GP does not understand B12 deficiency, getting additional injections is no easy matter. Sadly.

Here's some information about serum B12 testing: (Problems with Serum B12 Test) (Testing B12 During Treatment)

And no, reference ranges are not the same everywhere.

There are different units for measuring B12:

133 - 675 pmol/L (picomole per litre)

200 - 900 pg/ml (picogram per litre)

180 - 914 ng/L (nanograms per litre)

The above ranges are not fixed in stone due to the use of different lab machines, so reference ranges are calibrated and fluctuation, depending what machine is being used. Reference ranges are also adjusted according to local 'determinations' of population statistical norms (for want of a better way of putting it). Understand variations can be quite wide - normal reference range for my serum B12 was quoted as 240 - 900 ng/L. So...refererence ranges vary widely and have to be interpreted according to the reference range provided alongside with the actual test result.

About ongoing testing - those with PA and/or B12 deficiency often have other absorption problems and so testing folate, ferritin (marker of iron deficiency anaemia) and vitamin D, as a minimum, on an annual basis (to check that levels are being maintained) would be best practice - but not many GPs do this. Unless asked - and then the sometimes protest.

So...don't worry if serum B12 levels are not tested following commencement of injections. Normal reference range no longer applies and what really matters is having injections frequently enough to keep symptoms at bay.


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