On my B12 thread, I have a copy and link to Dr. Snow's article.

This research article has changed the way doctors should view B12 issues in people.

http://neurotalk.psychcentral.com/post698522-70.html

He states in that article that some few people will test out at 400 or close to and still have neuro issues. He recommends taking the B12 anyway for those patients.

You know there is a transporter to the CNS that moves B12 from the serum to the brain and spinal cord. That could not be working properly. Also people tend to store B12 in the liver, so if that is overactive it would pull B12 out of the serum making it unavailable to other sites. So there may be factors what exist in some people that just require higher levels.

Dr. Snow states that B12 is so inexpensive and benign it is not sensible to withhold it when neurological symptoms are present.

I really don't think the sublingual is very efficient. You end up swallowing the dissolved B12 in your saliva. The B12 molecule is huge and not easily passed thru membranes.

So most are sublingual...I just chew them and swallow them.

But one to avoid is "extended release".

There is a new one coming which I expect to be more expensive.
If you find this please let us know about it:
http://findarticles.com/p/articles/m.../ai_n30959773/

I expected it here by now...