Vitamin B6 treatment for tardive dyskinesia: a randomized, double-blind, placebo-controlled, crossover study.

Background: Tardive dyskinesia (TD) is a significant clinical problem. Vitamin B6 is a potent antioxidant and takes part in almost all of the possible mechanisms that are suggested as being associated with appearance of TD. The aims of this study were (1) to reexamine the efficacy and safety of higher doses of vitamin B6 versus placebo in a greater sample of patients for a longer time and (2) to evaluate the carryover effect of vitamin B6.