Hi, and thanks for the speedy response!

I'm slightly nervous that I'll get grilled if I ask for my results, but I suppose it's not a big deal to ring up reception and ask them to dig them out. Normally they just pass on the message "it's normal" and tell me that's all the doctor said to them. The tests were run a year or so ago.

I do know about taking B12 on an empty stomach, yep. At the moment I'm going for evenings as they are making me tired, although last night I tried that and then couldn't get to sleep for a while. I'll see how it works out.

Am I right in thinking that you end up absorbing less if you take it orally than you do sublingually, so it's likely to end up being a higher dose? Or is the whole sublingual thing a red herring? They do get rather intense about some things on PR, I've noticed.

I've not been on the H2 blockers for long. I do wish they'd run some investigations into why I'm getting all this stomach pain and itchiness, instead of just bunging me on more and more meds, but that's what tends to happen when you have ME.

Any idea how fast I should increase the dosage of the B12? And is there any type of reaction which is a sign that I should back off, rather than waiting it out?