Hi. I have been self administering B12 injections for 34 years following being diagnosed with macrocytic cells.
I have moved house and my new GP has discontinued them as a blood test identified normal levels. I must point out that I had received an injection ,4 months prior to the test.
Is this normal practice after so many years?
no - your GP just doesn't understand how a B12 absorption problem works and is acting on a misconception that normal levels in blood means everything is okay - it most definitely does not. If you have an absorption problem then you can't absorb B12 from your food - you are reliant on the amounts that are in your blood being sufficient to supply what your cells need. You can't rely on stores in the liver as releasing these relies on the same mechanism as you use to absorb B12 from your food.
Serum B12 isn't a good guide to what is happening with B12 at the cell level - useful-ish for diiagnosing an absorption problem but you already know you have that. The fact that you have had loading shots introduces factors that mean the normal range just doesn't apply in the same way.
You can try pointing out to your GP that, if they look at the BCSH guidelines which they can find on the BNF,treatment for PA (the most likely cause of your initial deficiency) is for life and that using serum B12 levels are not used as a guide to treatment. You could try pointing them at the area of the PAS website specifically aimed at medical practitioners.
pernicious-anaemia-society....
onlinelibrary.wiley.com/doi...
if that doesn't work or if you feel you need some more specific guidance (though might take a while to contact them) you could try joining and contacting the PAS directly
Was your Folate level tested by your new GP Chaka ?
Not sure
A possible cause of macrocytic anemia is deficiency or defective utilization of vitamin B12 or folate.
It is important that your Folate level is monitored as this is essential to process the B12.
There is a complex interaction between folic acid, vitamin B12 and iron. A deficiency of one may be "masked" by excess of another so the three must always be in balance.
Symptoms of a folate deficiency can include:
symptoms related to anaemia
reduced sense of taste
diarrhoea
numbness and tingling in the feet and hands
muscle weakness
depression
Folic acid works closely with vitamin B12 in making red blood cells and helps iron function properly in the body.
I am not a medically trained person but I've had P.A. (a form of B12 deficiency) for more than 45 years.
I wish you well
Many thanks. I will ask what my folic acid levels were.
This is a link to the latest BMJ research document summary (GP would probably be able to access the full document):
It states that there is no reliable test and, particularly, that there is no point in doctors testing serum levels (bottom of page 4 ' under, 'How is Response to treatment assessed' ), once b12 treatment has been given as levels will not reflect how effective the treatment is (unless still low) - it is the clinical condition of the patient that matters.
"Cobalamin and holotranscobalamin levels are not helpful because they increase with vitamin B12 influx regardless of the effectiveness of treatment, and retesting is not usually required."
The document also contains information regarding frequency of injections for neurological symptoms :'every other day until no further improvement (British National Formulary).
This is particularly important as it seems, the more severe the symptoms, the longer it takes to recover, particularly if they are neurological, - Dutch results in pinned posts.
B12 injections discontinued
B12 injections 
B12 injections been stopped
B12 INJECTIONS
B12 levels 6 months after loading injections
