Pernicious Anaemia Society

Where can I find information relating to how long a person could inject hydroxocobalamin once every other day, as advised in BNF guidelines?

My GP allowed me to trial one B12 injection every other day for the period of a month after I showed him the information in the BNF guidelines relating to those people who have a B12 reading of below 200 as well as neurological symptoms (as do I). I improved enormously over that time, although by no means completely.

However, after one month, he stopped the treatment as he said he did not know what the long term effects of injecting in this way would be and that it was too risky to my health to continue. He wanted to know what 'until no further improvement' meant in real terms.

I am now injecting once weekly while we try to find an answer to his concerns - and my symptoms have returned sufficiently that I am again unable to work. This, however, has not shifted his stance. So, does anyone know:

a) where I might find documentation to support my return to 1 injection every other day for a longer period of time;

b) the names of any doctors (private or NHS) who would be able to advise either myself or my doctor?

Thank you so much.


4 Replies

Your Doctor has been brilliant, it's so nice to hear that some actually do listen. The Pernicious Anaemia Society could probably answer your question more fully than me, but here are some things I have picked up along the way:

- Maybe your Doctor could speak to Dr Chandy (see

- Re dosage concerns, as far as I'm aware the World Health Organisation has set no upper limit on B12 levels as there is no evidence of toxicity. It is water soluble and any excess is excreted in urine. This is from the website:

- People with homocystinuria get a B12 injection every 1-3 days for life - and it starts when diagnosed shortly after birth.

- Also, if you were being treated for cyanide poisoning, you'd be given an IV infusion of Hydroxo at a strength 5,000 times what is in one injection - and it can be repeated if necessary.

I hope this helps, Hampster


That is so helpful - many, many thanks. I did give my doctor the contact details of Dr Chandy but there has been no response. I shall try again. In the meantime, I will have a look at the links that you have provided. Fingers crossed!


I agree with every word by Hampster1 above.

As far as the words of the BNF are concerned it seems plain that "until no further improvement" means that all neurological symptoms have been resolved as far as they can be.

The best judge of that is you, the patient, surely?

You will get answers and support from the Pernicious Anaemia Society as Hampster1 suggested. There is a helpline available I think to members, here is the website link, though I think you are probably well aware of it already.


Thanks. The problem that I have is the discussion about treatment being symptom-led. My GP prefers to look at printed guidelines and protocols rather than the symptoms I bring with me! He and I sometimes have some distance in interpretation for phrases such as 'until no further improvement'! The links provided here are very helpful indeed to me. Fingers crossed!


You may also like...