Pernicious Anaemia Society

Does spheracytosis aggrevate the symptoms of B12 deficiency?

My B12 is 160, just had my 4th injection at one a week but still have headaches and feeling exhausted; I rarely go a whole day without sleeping. Is my spheracytosis making the condition worse or is it because I have not had my B12 injections quickly enough? I am concerned that I will soon go on to one injection a month without actually feeling any better.

6 Replies

Hi helonlegs, one injection a week is not close enough together for the loading dose, it's meant to be 6 injections over 2 weeks, i.e. one every other day. Do you know why your doctor has spaced them out like this?

If you have neuro involvement it's actually meant to be one every other day until no further improvement, i.e. you keep on the loading dose for as long as you need (very few doctors actually do this but they should, it's in the BNF).

Here is the guidelines, see "dose":

I don't know anything about your other medical condition, so it may well be the spacing out has something to do with that, so you'll need to ask your doctor.

It's common to experience a worsening of symptoms or headaches on the loading dose. Make sure you're not too low on folate - you need to be well within the top half of the range. If you are at the bottom of the range your doctor should be prescribing 5mg folic acid, and on injection day take this about an hour before. Again I'm going to caveat with me not knowing anything about spheracytosis - it might be different for you? What are your ferritin/iron levels like?

I started to feel great after my 4th injection, but had returning symptoms only 2 weeks after the loading dose ended. Luckily my doctor has agreed to more frequent injections for now. Everyone is different. It takes time to heal, with ups and downs along the way. You may find that you need to stay on frequent injections for a while, if your doctor will agree.

The first thing you need to do is find out why he's not following BNF guidelines...



Hi Hampster, thanks for your reply.

I was only offered one or two injections a week, opted for two a week but due to half the nurses being on holiday I could only get one appointment a week.

I have been back to the doctor this evening who told me that only one injection a week is fine, I could just have one a month, and I should feel immediately better a short time after the injection. He is sending me for a further blood test to check my B12 levels and iron levels.

I will call tomorrow and speak to my GP about this


You might find this interesting. It is from the website. It talks about how the BNF guidelines have changed, and why improved treatment is necessary:


I meant to say also there's not much point in further B12 testing once you've started treatment, your levels will be really high! What happens then is they say "you're fine now" and stop the injections. This is very misguided, serum B12 is not a measure of what's going on at tissue level.

Are you having further investigations to establish the cause of your deficiency? If it's classic PA they would usually test for Intrinsic Factor antibodies and Parietal Cell antibodies.


Thanks for your feedback and the info on dosage. Did not get far with the doctor and yes, he did say we will see the levels from your blood test and amend the dosage. No response as to why they are not following guidelines even though I spoke to the senior doctor in the practice. I will try another one.


Sounds like you might have some persuading to do, here is the professional reference article on B12d:

The wording is very specific in the section headed "Management". It repeats the dosing/frequency guidelines I gave above, but also it states that:

"It should be remembered that serum B12 is not always an accurate reflection of deficiency at a cellular level.[24] It is perhaps for this reason that some patients become symptomatic if the frequency of their injections is reduced, despite having normal serum B12 levels."

This is basically confirming that treatment needs to be tailored to symptoms, not blood test results.

All you can do is get as knowledgeable as you can, and try and educate your doctor. Print of anything you think is relevant, drop it in to the doctor in advance, then make an appointment to discuss. Also be sure and ask them what investigations they plan to do to establish the cause of your B12d. Good luck!

H x


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