Just under 2 months ago I was dx "borderline" b-12 defiient (serum level of 220), with plenty of symptoms, although still unclear how many of them were due to b-12 or to what extent.

Since then I have gotten 5 B-12 shots (usual dose of cyano) and have also been taking 1000 mcg sublingual methyl B-12 daily for all but 1 week of that time.

The other day I got my levels retested, and they came out at around 540.

This was 2 weeks since my last shot, and about 24 hrs. since my last oral dose. They also took MMA and homocysteine, but those haven't come back yet. Folate levels were fine.

My question is: with that much B-12 entering my system over that period of time, is 540 good or bad? I know it's out of the danger range, but I'm trying to get clues as to whether or not I have PA & how bad my absorption is. Should it have increased more? Am I not getting enough shots?

Has anyone found any guides for how quickly serum levels should increase on a particular dosage & schedule?

Thanks!

My symptoms are not gone, BTW, although they are improved. So I'm also left wondering if I'm still healing from the B-12 or if there is another cause. I suspect it's both.