PROBLEMS OF A HIGH CONTENT OF VITAMIN-A I N THE LIVER OF CALVES, CATTLE, SHEEP AND PIGS FOR THE HUMAN-NUTRITION - AMOUNT OF THE STORAGE ANDTERATOGENIC MECHANISM OF ACTION

Cases of hypervitaminosis A in men - especially in pregnant women, wit h development of malformations - are reported. The existence of withdr awal times to slaughter after the application of vitamin-A-containing preparations with a content of 10 000 to 10(6) international units and more is described. The content of vitamin A in the liver of monogastr ic animals is closely related to that in the feed. In ruminants about 40 to 70% of the vitamin A of the feed is decomposed by the microorgan isms in the forestomachs. The amount of vitamin A stored in the liver after a therapeutic application is dependent of the initial content. T he velocity of the depletion of the stores at a carotin- and vitamin-A -poor feeding is described. In ruminants and pigs in the account of th e properties of the placenta no embryotoxicity of a therapeutic dosis of vitamin A is to be expected. The mechanism of the teratogenesis by vitamin A in mice is described.