Headache and papilledema are features of toxicity of which vitamin?

Ans. is 'a' i.e., Vitamin AHypervitaminosis A* Caused by consumption of food rich in vitamin A like fish or liver (not by excessive intake of carotenoids as the conversion of carotene to vitamin A is regulated).* Mechanism of toxicity:# Suppresses osteoblasts and stimulates osteoclasts.# High retinol concentrations stimulate lysosomal enzyme release and cause local tissue damage.# Features include anorexia, irritability, headache, skin peeling, vomiting. Headache, vomiting and papilledema are found to be caused by increase in intracranial tension. Hence this condition is called as pseudotumourcerebri. As vitamin A stimulates osteoclasts, hypercalcemia, bony projections, pathological fractures are also observed as features.