Thanks, MrsD, I'll get the result number from my doc for my recent B12 test. I had gotten a D3 test a couple of months ago after going on a larger daily supplement (to prevent cluster headaches) and had raised it in about 4 months from 35 to 57. So I think I'm reasonably okay there.

I'm also taking 100 mcg Synthroid daily for hypothyroidism brought on by radiation treatment for throat cancer 4 years ago.

I've read some of the posts in the B12 thread you suggested... interesting stuff indeed. Do you think that for starters I get myself some B12 tablets and just dig in? I should add that I'm a vegetarian who eats fish maybe 3 times a month, so I'm certainly not getting much of it naturally. And if so, what should I be looking for in the brand labeling - anything in particular?

Many, many thanks for taking your valuable time to advise me!