After suffering with post viral syndrome for over 12 months (parvovirus in spring 2010), viral thyroiditis, and subsequent chronic fatigue, chronic pain, I discovered I had B12 deficiency (149 pmol/L). I was put on 1200IU oral tablets of B12 for 1 month to see if I responded to them before resorting to injections. After I started taking them I noticed less fatigue and better concentration. Pain levels, especially pain along my forearms that are prehaps nerve pain(?) were reduced (but not gone). However when I had my level tested again (about 4 weeks after starting the tablets) I am now in the 700's (over the normal limit?). I have been told to stop taking them. My Dr is also surprised that I have responded in such a way and that such a big change should not occur over such a short time span. My symptoms have already started coming back, especially the burning/pain along my forearms/back of hand and lower legs/top of feet. I'm also wondering why he is concerned that it has shot up so quickly?
Any help and advice would be appreciated.