Combined vitamin B6-magnesium treatment in autism spectrum disorder.

Nye C and Brice A.

(Cochrane Review) In: The Cochrane Library, Issue 1 2003. Oxford: Update Software.

Bottom Line

Do Vitamin B6 and magnesium supplements improve behaviour and social and communication skills in children and adults with autism?

  • Researchers looked at studies that tested whether Vitamin B6 and magnesium supplements improve functioning in people with autism
  • They reviewed studies that were designed to see whether the supplements improved use of language or increased the children’s ability to respond to their environment or to other people.
  • The studies reviewed were of poor quality and could not answer the questions.
  • It is not known if the supplements improve symptoms in children and adults with autism.

Question: Do Vitamin B6 and magnesium supplements improve behaviour and social and communication skills in children and adults with autism?

Background: In the early 1950s doctors tried using Vitamin B6 to treat people with schizophrenia. Later studies showed that there was possible improvement in language use, leading researchers to try supplements in children with autism. The high doses used caused side effects such as bedwetting, irritability, and oversensitivity to sound, but magnesium was added to reduce or eliminate these problems.

Most of the evidence during the early phases of this research was based on single case reports and not on controlled research. The purpose of this review was to search published literature to find reports of rigorous and scientifically valid research on this topic to demonstrate whether or not Vitamin B6 and magnesium supplements improve functioning in people with autism.

Data sources: Using a combination of the terms "child-development-disorders-pervasive," "speech disorders," "B6," "pyridoxine," "magnesium," "vitamin B6", the authors searched the Cochrane Controlled Trials Register, MEDLINE, EMBASE, and Dissertation Abstracts International using the FirstSearch search engine and handsearched the Journal of Autism and Developmental Disabilities. A further step in the process was to look at the reference lists of all the articles found and search for missed studies.

Study Selection

Types of Studies: Randomized trials in which one group of participants was given a combination of Vitamin B6 and magnesium and a control group was given either a placebo or no treatment.

Types of Participants: Children and adults with a diagnosis of autism.

Types of Interventions: Combination Vitamin B6 and magnesium supplementation in either powder or pill form.

Types of Outcome Measures:

1. Verbal behaviour (increased use of language)

2. Non-verbal behaviour (improved ability to respond to

3. Social interaction (increased ability to respond to other people).

Data extraction: Using the inclusion criteria described above, the authors summarized the findings of the two studies and commented on the design, participants, interventions and outcomes found.

Main results: Of the 58 articles found, two studies met the inclusion criteria and were included in the review. Both of the studies used a double-blind crossover design. The Tolbert study did not report the data in a form that could be readily analyzed and the author was unable to provide further information to make it so. The Findling study found no significant difference between the active treatment and placebo conditions.

Conclusions: There is no evidence of an acceptably high level to state that a combination of Vitamin B6 and magnesium improves the behaviour or social and communication skills of children and adults with autism.

The two included studies were:

Findling RL, Maxwell K, Scotese-Wojtila L, Huang J.

High-dose pyridoxine and magnesium administration in children: An absence of salutary effect in a double-blind, placebo-controlled study. Journal of Autism and Developmental Disorders 1997; 27(4): 467-78.

Tolbert L, Haigler t, Waits, MM, Dennis T.

Brief report: Lack of response in an autistic population to a low dose clinical trial of pyridoxine plus magnesium. Journal of Autism and Developmental Disorders 1993; 23(1): 193-9.