i have a personal experience with B-12. when i was testing for mercury poisoning a few years ago, i started with basic tests. i learned that B-12 would pull mercury from my teeth and chelate it. i also knew that the 24 hour urine test i was taking was not a very good indicator of measuring mercury load in the body because mercury doesn't hang out in the urine very long. so, i figured i could manipulate the test a bit by taking some B-12 during the test. i ground up one 100mcg tablet and swallowed it. i got extremely sick to my stomach. a little while later, i took one more without grinding it. i can truly say that within a very short time, this was one of the most illest (if you will) times of my life. just from that first one i took, i was green. i knew that it was bringing a lot of mercury out in my system. i don't know the exact result of that particular test, as i did a few tests and my doctor told me i had mercury poisoning (and nickel poisoning, as i tested for that as well).