Can someone please explain to me why my b12 level is 1400, SI 3x per week, iron is 12 range (11-34) and folate is >2500 normal is >1100. Symptoms were all almost completely gone after 4.5 months and all of a sudden this week many symptoms have reared their ugly head. They seem to show up and disappear. The worst being the throat tightening. It is driving me crazy! Wondering if I should try taking b12 sublingual on days in between injections. I just can't understand why all of a sudden this happens. So frustrating!