Efficacy of vitamin B6 and magnesium in the treatment of autism: a methodology review and summary of outcomes.

Pauling's orthomolecular hypothesis appeared in 1968, stating that some forms of mental illness and disease are related to biochemical errors in the body. Vitamin therapy is believed to be a means of compensating for such errors. There have been few empirical studies on vitamin therapy in individuals with autism. This article presents a critical analysis of the 12 published studies located through an extensive computerized search. Studies were systematically evaluated to provide an objective assessment of empirical evidence supporting the efficacy of vitamin treatment. The majority of studies report a favorable response to vitamin treatment. However, interpretation of these positive findings needs to be tempered because of methodological shortcomings inherent in many of the studies. For example, a number of studies employed imprecise outcome measures, were based on small samples and possible repeat use of the same subjects in more than one study, did not adjust for regression effects in measuring improvement, and omitted collecting long-term follow-up data. Recommendations are offered to assist researchers in designing future investigations.