606 IX. CAROTENOIDS AND VITAMINS A 



reader is referred to the excellent review on hypervitaminosis A by Nieman 

 and Klein Obbink^'"^ which appeared in 1954, and to the chapter of Wol- 

 bach'"-^ and that of Mason ^"-^ in the recent monograph on The Vitamins} 



{2) Symptoms of Hypervitaminosis A in A nimals 



Two types of experimental hypervitaminosis A occur, namely acute and 

 chronic intoxication. Acute intoxication supervenes within a few hours 

 after the administration of excessive doses of vitamin A, which are usually 

 given by injection. As an example, the toxic symptoms following the sub- 

 cutaneous injection of 0.5 c.c. of a 25% solution of "biosterol" (or "fat- 

 soluble A") into rats and mice, as reported by Takahashi et a/.''*^^ and by 

 Matsuoka,^^"* which were followed by death, are an example of the acute 

 type of toxicity. From fifteen to twenty minutes after the injection, the 

 hind legs became paralyzed, and generalized cramps developed, associated 

 with anemia, and a mucous discharge from the mouth. The animals be- 

 came unconscious and died.'^°^ On the other hand, chronic intoxication 

 with vitamin A appears when smaller doses of vitamin A are continued 

 over a period of time. In general, hypervitaminosis A results in arrested 

 growth, leading to a loss in weight, and marked emaciation, accompanied 

 by anemia and cachexia. RodahP^^^ is of the opinion that the reduction 

 in the growth rate results from a decreased food intake attributable to the 

 lessening of appetite caused by the overdoses of vitamin A. 



a. Skin Symptoms. Trophic changes occur in the epithelium which lead 

 to a localized loss of hair; the bare patches are frequently colored red, 

 indicating a hyperemia, and the hair becomes matted. That this effect 

 of hypervitaminosis A is generalized is indicated by the fact that it is 

 observed in the hedgehog (complete loss of quills thirty-four days after 

 the injection of 100,000 I.U. of vitamin A^^^"), and in the rat. In the latter 

 animal, baldness ensued within a month after the injection of high dosages 

 of the vitamin. ^^'^ 



Local appUcation of vitamin A to the skin produces a strong contact 



ii»6 c. Nieman and H. J. Klein Obbink, Vitamins and Hormones, 12, 69-99 (1954). 



"" L. Takahashi, Z. Nakamiya, K. Kawakami, and T. Kitasato, Sci. Papers Inst. 

 Phys. Cheni. Research (Tokyo), 3, 81-145 (1925). 



I'os M. Matsuoka, Bull. Inst. Phys. Chem. Research (Tokyo), 13, No. 10, 1267-1283 

 (1934); Chem. Ahst., 29, 5509 (1935); Sci. Papers Inst. Phys. Chem. Research, 25, Abst., 

 71-73 (Oct., 1934). 



I'os K. Rodahl, The Toxic Effect of Polar Bear Liver, Norsk Polar institutt Skr., No. 92, 

 1-90(1949). 



nio w Weslaw, B. Wronski, A. Wroblewski, and B. Wroblewski, Klin. Wochschr., 17, 

 777-781, 879-884 (1938). 



