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.
Valproic acid is also available is a liquid form (DepakeneÂ®) and an IV form (DepaconÂ®). In the brain, valproic acid inhibits voltage sensitive sodium (Na+) channels. Valproic acid also increases brain GABA levels. GABA is an inhibitory neurotransmitter.Valproic acid is a broad-spectrum anti-epileptic drug (AED).