Firstly I have it myself and due well on regular injections, however it is very poorly diagnosed and managed in this country, patients popped onto pills when they should be having jabs.
1. pernicious-anaemia-society.....
2 pulsetoday.co.uk/news/clini...
GP's appear to be poorly trained in diagnosis and management, it used to be the case that you were given injections according to symptoms not just a linear blood test, most people I know with it badly need more than an injection every three months so end up paying for extra ones. I do this myself.
It is not unusual to have a B12 problem if you are a Thyroid patient, taking a pill for B12 will alter your result for many weeks with the GP and may show that you have high levels, but not how your body is taking it up, and rather like low Iron will stop your Thyroid medication working properly, low Folate if not treated will stop you taking up your B12, so all a bit of a jigsaw.
Mary F