[matthews]

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.

[glenntaj]

--with the supplementation, that doesn't mean it's all working on the cellular level.

Repairs due to B12 deficiency are typically rather slow, with a lot of ups and downs. It is true that some people feel better quickly, especially in terms of energy levels, but if there's been considerable cellular damage done--and with the former levels you report, I suspect there was--it may take a long time for whatever repairs that can occur to be completed, and when your body gets down to that serious business (and you should be sure to have sufficent quantities of B6, folate, etc., as well--B12 acts in concert with these), don't be surprised if you feel as if you're having "setbacks".

The best way to track this is in long term retrospect--week to week, even month to month. See if there is overall improvement over these time frames.

I do suspect that you do have considerable malabsorption issues, and would probably benefit from higher dosing; you could probably go to 3000-5000mcg/day of methylcobalamin. (There's no known toxicity level of B12.) You might notice a jump in energy or "hyper-ness" if you do.

Most of us like to keep our serum B12 levels very high--in four digits--to make sure our tissues are bathed by a constant high concentration of B12. Those with malabsoprtion/storage issues may have to take the higher does to accomplish this.