Re: Low B12- at what point could it cause symptoms?
I feel your frustration!
The problem seems to be that you are being treated as if it's a dietary deficiency, whilst you're sure it isn't.
Logically, if you can convince your doctor it isn't dietary then, following NHS guidelines, your treatment should be changed to B12 injections (loading doses plus maintenance doses).
Are you up to making a firm and persistant request to your Doctor? I don't know how comfortable you are with that sort of situation (I know I'm terrible and avoid confrontation at all costs) but if you can it might help. Getting things down on paper is good, as is taking someone (calm) with you if you need the backup.
What you need to tell him is that you'd like to try B12 injections. You say he thinks they are unneccesary and is reluctant to prescribe them, but there is still no clinical reason for him to refuse.
The points you need to raise are along the lines below:
- you have had consistantly low B12 results for over a year now.
- you eat a healthy diet including plenty of meat, eggs and dairy (not vegan/vegetarian/anorexic etc).
- previous B12 dietary supplements had no or minimal efect.
- you understand that whilst he doesn't think the depression/bipolar/fatigue are B12 related, B12 injections can do you no harm and if there's even a small chance they might help, surely they are worth trying now.
Just keep repeating that you'd like to try the B12 injections.
On the plus side, your Doctor seems to have been monitoring you well, so it isn't like he is completely uninterested. He is, however, taking what seems to be a slow approach to treatment. My guess would be this is because you are generally healthy and not presenting with any symptoms he would, rightly or wrongly, put down to B12 deficiency and therefore he sees no need for speedy improvements in your levels. If you flat out and out request injections he can either agree or disagree. At least you'll know where you stand, and luckily, being the UK, you are free to change GPs if necessary with no explanation or penalty.
Have you gone through some of the low B12 symptoms lists online to make sure you're presenting with everything? I know a whole load of odd niggly stuff I'd been discounting suddenly made a lot of sense in the light of a low B12 diagnosis.