Glutamic acid is a nonessential amino
acid, which means that it is manufactured from other amino acids in the liver;
it does not have to be obtained directly through the diet.
Glutamic acid is interconverted to
glutamine, which is known to be a very important amino acid in preventing
ammonia intoxication, and is also a brain-active neurotransmitter substance.
Adults may ingest 20 to 35 mg per day of this amino acid without any apparent
ill effects. In general, glutamine has been used therapeutically rather than
glutamate in the management of certain types of problems such as alcoholism,
liver problems, and certain biochemical problems.
Metabolism of glutamic acid can result in
the formation of gamma-aminobutyric acid (GABA), which is known to be an
inhibitory neurotransmitter in the brain. Deficiencies of GABA can result in
excess activity of certain regions of the brain and seizures or behavioral
hyperactivity. Dietary glutamic acid does not have a significant effect on GABA
in the nervous system.