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.
Antidepressant and antipsychotic drugs cause hyponatremia through the development of SIADH. Antiepileptic drugs: Carbamezepine, oxcarbazepine, sodium valproate, lamotrigine. Carbamazepine, oxcarbazepine and sodium valproate cause an increase in production of ADH, whereas carbamazepine and lamotrigine cause potentiation of ADH effect. Oxcarbazepine has been found to cause hyponatremia more commonly as compared to carbamazepine.