My B12 status truly confuses me. I had it tested recently and it was off the charts (>2,000 pg/ml). I do take some B12, but it is a relatively small amount, all oral, and mostly cyanocobolamin. Folate was normal. The other thing is that when I have had B12 injections, they make me feel horrible: very low energy, lethargic. I'm hoping to retest soon, having stopped taking B12 supplements to see if the high levels are coming from supplementation, as there as some very bad things that can cause high B12 levels.
Does anyone here know if you can get extremely high B12 serum levels from oral supplementation?