while doing my online reading and research today I came across an article on the MERCOLA site which maybe of benefit to people looking for understanding of the process involved with testing for B12 deficiency.............

I have NO commercial interest in this site

http://www.mercola.com/2003/may/28/vitamin_b-12.htm

Just thought to pass this along for your information

See Ya later, Cheer's from Clare in Tassie