Thanks, everyone for your replies. Still hoping to hear from others as well.

mrsd, thanks for your advice. I don't think i'm trying to make excuses for my doc. He was very straight with me, after reading up on it said "I should've done these other tests (folic acid, HC, maybe MMA) before starting you on the shots".

I understand that's both to confirm that there's a functional deficiency, and to establish a baseline to see if therapy has an effect.

That paper looks great, thanks for the link, but it too recommends the tests be done before therapy is started. Too late for that.

But the fact that the shots almost immediately started to lessen my neuro symptoms seems to me a big indicator that I was in fact deficient, test or no test. Right?

The question at this point is whether it helps at all to do those tests now, after I've already had 3 shots and several oral supplements. He thought the results would be skewed by the recent supplementation and so weren't worth doing.

If you think otherwise, please let me know. I'm very willing to request he do the tests now, if I've got some info to back me up.

M.