Overview: The Biopsychopharmacology
of Vitamin B6
Vernon M. Neppe and Willem J. Serfontein
Vitamin B6 (pyridoxine), in a variety of chemical
forms, is a coenzyme in a large number of extremely
important metabolic processes in the nervous system.
Consequently, deficiency could theoretically produce
such diverse pictures as neuropathy epilepsy, and behavior
disturbance. In practice, however, despite several studies
suggesting that mild deficiency states are common in
both psychiatric patients and the normal population,
few patients appear symptomatic. Pyridoxine is frequently
used in the management of premenstrual syndromes and
in pregnancy-related depression. There is substantial
theoretical support for this empirical approach. It
also has been used in atypical cases of infantile autism
in megadoses, but this therapy is unproven. Its use
in schizophrenia is also unproven and it is unlikely
that it causes any kind of improvement. It is extremely
promising, however, in some types of homocystinuria
and Down's syndrome, and in both there are appropriate
biochemical correlates that motivate its use. It is
clearly indicated in pyridoxine deficiency infantile
epilepsy. The drug may become more useful when used
in appropriate combinations, e.g., one study suggested
its combination use with magnesium in autism. Moreover,
tempering its increased use is the discovery of a predominantly
sensory neuropathy that is reversible on cessation of
high-dose daily vitamin B6 therapy. Guidelines for future
research and for possible use in psychiatry are made.
The varying formulations of vitamin B6 have different
kinetics and may imply different use.
Keywords
Ascorbic acid - Attention deficit disorder - Autism
- Behavior disturbance - Down's syndrome - Drug interactions
- Epilepsy - Homocystinuria - Hyperventilation syndrome
- Megadose therapy - Mental retardation - Monoamine
oxidase inhibitors - Neuropathy - Premenstrual depression
- Pyridoxal phosphate - Pyridoxine - Schizophrenia -
Theory and practice in psychiatry - Vitamin B6.
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