This might be what your looking for.....
http://www.yorkietalk.com/forums/off...-you-know.html
This book is
very good and has a lot more info than what I could ever put here.....you can also get it at the library.....
Amazon.com: Could It Be B12?: An Epidemic of...
If your going to get your B12 checked the urine MMA is the better test to get, also have your homocysteine level checked......if your B12 is low chances are this might be high, if it is, it greatly increases your chances of having a heart attack or stroke.....
Hope this helps.....