Prevalence of vitamin A deficiency. Vitamin A deficiency (VAD) is a lack of vitamin A in humans. It is common in poorer countries but rarely seen in more developed countries. Nyctalopia (night blindness) is one of the first signs of VAD.revalence of vitamin A deficiency. Vitamin A deficiency (VAD) is a lack of vitamin A in humans. It is common in poorer countries but rarely seen in more developed countries. Nyctalopia (night blindness) is one of the first signs of VAD.
Both lithium and valproate have been reported to increase rat CSF GABA levels. Regarding valproate, animal studies reported that it enhances GABA levels, GABA synaptic release, GAD activity, neuronal GABA responsiveness, and inhibits GABA-T in several brain regions.
Neurotransmitters: Exciting and Inhibiting. Gamma-Amino-Butyric-Acid, or GABA, is the chief inhibitory neurotransmitter in the human brain. Along with serotonin, dopamine, glutamate, glycine, histamine, and norepinephrine, among dozens of other neurotransmitters, GABA regulates brain function. L-theanine also increases GABA activity. This amino acid is found in high doses in green tea. -Foods rich in B-complex vitamins, particularly inositol, also prompt GABA production. In fact, B-vitamins are necessary for the functioning of nearly all brain processes and chemicals.