Why is vitamin B6 effective in alleviating the symptoms of autism?

Med Hypotheses. 2018 Jun;115:103-106. doi: 10.1016/j.mehy.2018.04.007. Epub 2018 Apr 12.


Many factors are reported to be involved in the complex pathophysiological processes of autism, suggesting that there is considerable variability in the manifestations of this disease. Several interventions are used to treat this disorder. Among them, vitamin B6 is widely used to treat the symptoms observed in autism. Vitamin B6 is beneficial for about half of autistic individuals in decreasing behavioral problems. However, until now, it remains unknown why vitamin B6 is effective for this disease. Although the exact pathogenesis is not defined, it is evident that certain neurotransmitter systems are impaired in the brains of autistic patients, causing the symptoms observed in the disease. In fact, impairment of many neurotransmitter systems has been reported, including GABA, serotonin, dopamine, and noradrenalin. Furthermore, vitamin B6 is important for the synthesis of many neurotransmitters, including GABA, serotonin, dopamine, noradrenalin, histamine, glycine, and d-serine, indicating that vitamin B6 supplementation may enhance many neurotransmitter systems. Thus, vitamin B6 supplementation can treat the impaired neurotransmitter systems in a given patient, even if the actual impaired neurotransmitter systems are not defined in that patient.

Keywords: Autism; Dopamine; GABA; Serotonin; Vitamin B6.

MeSH terms

  • Autistic Disorder / drug therapy*
  • Autistic Disorder / physiopathology
  • Dopamine / physiology
  • Glycine / physiology
  • Histamine / physiology
  • Humans
  • Models, Neurological
  • Neurotransmitter Agents / physiology
  • Norepinephrine / physiology
  • Serine / biosynthesis
  • Serotonin / physiology
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology
  • Vitamin B 6 / physiology
  • Vitamin B 6 / therapeutic use*
  • gamma-Aminobutyric Acid / physiology


  • Neurotransmitter Agents
  • Serotonin
  • Serine
  • gamma-Aminobutyric Acid
  • Vitamin B 6
  • Histamine
  • Glycine
  • Dopamine
  • Norepinephrine