|—n , pl P vitamins|
|citrin, Also called: bioflavonoid any of a group of water-soluble crystalline substances occurring mainly in citrus fruits, blackcurrants, and rosehips: they regulate the permeability of the blood capillaries|
vitamin P n.
A water-soluble vitamin, found as a crystalline substance especially in citrus juices, that functions as a bioflavonoid in promoting capillary resistance to hemorrhaging. Also called capillary permeability factor.