Vitamin B12 (methycobalamin form)
Most wholistic health care professionals feel that the methycobalamin form of B12 is to be preferred over the hydroxocobalamin or cyanocobalamin forms. The latter is the most commonly used, is a cheap, synthetic formulation and contains minute quantities of cyanide. The cheaper form is routinely recommended, but we do not.
B12 is necessary for support of a healthy nervous system. B12 is found only in animal foods, so vegetarians and vegans are at risk for not getting enough B12. Since the body stores B12 for a long time, 10 or more years, it's easy for vegetarians to not realize they are not getting enough B12 to prevent nerve damage.