614 IX. CAROTENOIDS AND VITAMINS A 



noted that guinea pigs began to lose weight within five days when 1.5 c.c. 

 of Vogan (180,000 I.U. of vitamin A) were given daily. RodahP"^^ re- 

 ported similar toxic effects in rats, guinea pigs, rabbits, and yomig cock- 

 erels after the administration of vitamin A in doses comparable on the 

 weight basis; symptoms of toxicity began with dosages of 50 to 130 I.U./g. 

 body weight. Rigdon et al.~°^ observed failure to gain weight in ducks fol- 

 lowing doses of 200,000 I.U. of ^'itamin A/day, although no bone fractures 

 occurred. 



c. Acute and Chronic Toxicity in Man. The acute toxic dose of vitamin 

 A, when given orally to adult humans, is in excess of 1,000,000 I.U. Values 

 recorded by various investigators are as follows: Getz and co-workers, 

 2,000,000 I.U. (dull headache); 1174 Poslavskii and Bogatkina, 1,000,000 

 to 5,000,000 I.U. (as whale liver o\\);''^^ Rodahl and Moore, 7,500,000 

 I.U. (irritability, sluggishness, drowsiness, headache, vomiting) ;^^4 and 

 Oyenhart and Wassermann, 300,000 to 1,200,000 I.U. (no untoward 

 effects). "75 



When vitamin A is given repeatedly, the level for chronic toxicity ap- 

 pears to be about 600,000 I.U./day. According to Frey and Schoch,"^* 

 daily dosages of 400,000 I.U. can be readily tolerated by adults, over an 

 extended period. Moreover, Van Bruggen and Straumfjord^^'' reported 

 no untoward effects resulting from the administration of 100,000 I.U. of 

 \'itamin A per day over a period of eighteen months, and Argonz and Abin- 

 zano 1176.1177 consider the treatment of premenstrual tension with 200,000 

 I.U. of vitamin A daily as harmless, and, in most cases, beneficial. On the 

 other hand, several investigators"^^ -n^^ found that a daily intake of 600,000 

 to 1,000,000 I.U. of vitamin A precipitated the symptoms of hypervita- 

 minosis A. Rodahl and Moore^^'* reported that several forms of indis- 

 position, including dizziness, appeared within five days, in men, when they 

 were given 6,000,000 I.U. of vitamin A daily. 



Although the daily administration of 300,000 I.U. of vitamin A over 

 several weeks did not precipitate a hypervitaminotic condition in chil- 

 dren, "^^ toxicity was e\ddent in the case of a two-year-old tuberculous child 

 who received 400,000 I.U. (in four divided doses) weekly; the effect was 

 indicated by a reduced erythrocyte count and an increased sedimentation 



"'^ H. R. Getz, G. B. Hildebrand, and M. Finn, ./. Am. Med. Assoc, 112, 1308-1311 

 (1939). 



'"* J. C. 0.yenhart and C. Wassermann, El dia nied., 12 (1950); cited by C. Nieman 

 and J. Klein Obbink, Vitamins and Hormones, 12, 69-99 (1954), p. 83. 



'"^ J. Argonz and C. Abinzano, Semana med. {Buenos Aires), 56, 407-417 (1949). 



1'" J. Argonz and C. Abinzano, /. Clin. Endocrinol, 10, 1579-1590 (1950). 



'"« E. Lehman and H. G. Rapaport, /. Am. Med. Assoc, 114, 386-393 (1940j. 



