Each B vitamin is different. Japanese physicians inject 36 mg./day of methylcobalamine B-12 (that's 36,000 mcg!) to heal PN damaged nerves. It works with people and experimental animals. It's hard to imagine any amount of B-12 that you could afford that would cause damage.

On the other hand, some of the other B vitamins can be harmful to excess. A safe supplement limit would be either one B-100 formulation or two B-50 formulation tablets or capsules a day.

You can get info. on recommended amounts, therapeutic amounts, and recommended upper limits of the entire range of supplements, vitamins, and minerals at http://healthlibrary.epnet.com/GetCo...chunkiid=33802 .