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.
Olaparib: Use caution if coadministration of olaparib with valproic acid is necessary, due to a risk of altered olaparib exposure. Olaparib is a CYP3A4 substrate and in vitro substrate of P-glycoprotein (P-gp); valproic acid is a weak CYP3A4 inhibitor/inducer (in vitro), as well as an in vitro P-gp inducer.