FACTORS ALTERING CONCENTRATION OF CAROTENOIDS 503 



It has likewise been shown that the administration of massive doses of 

 vitamin A to chickens results in a pronounced decrease in the carotene 

 level of the plasma and of the egg yolk, 903 while vitamin A is being markedly 

 increased in these locations. These data are related to the observation of 

 Hammond and Harshaw 904 that there is a material in fortified cod-liver oil 

 which interferes with the deposition of xanthophyll in the shanks and skin 

 of chicks. The pigmentation-suppressing factor was later shown by 

 Rubin and Bird 905 to be vitamin A. Table 23 furnishes a summary of 

 these data. 



Table 23 



Effect of Several Levels of Vitamin A Intake on Carotenoid and Vitamin A 



Content of Plasma, Liver, Fat, and Egg Yolk of Chickens" 



° Data from H. J. Deuel, Jr., M. C. Hrubetz, F. H. Mattson, M. G. Morehouse, and 

 A. Richardson, J. Nutrition, 26, 673-685 (1943). 



When massive doses of vitamin A are administered over prolonged 

 periods, symptoms of hypervitaminosis A develop. According to 

 Josephs, 906 a hypervitaminemia A occurs, together with a lowered level of 

 blood carotene; in the one child studied, the serum vitamin A equaled 

 273 microgram per cent, while the serum carotene amounted to 1 10 micro- 

 gram per cent. In other reports of hypervitaminosis A in man, even 

 higher serum vitamin A levels were reported, namely 400 microgram per 

 cent, by Toomey and Morissette, 907 and 624 microgram per cent, by Roth- 



902 C. Jensen, P. D. Boyer, P. H. Phillips, I. W. Rupel, and N. S. Lundquist, J. Dairy 

 Sci., 25, 931-937 (1942). 



903 H. J. Deuel, Jr., M. C. Hrubetz, F. H. Mattson, M. G. Morehouse, and A. Richard- 

 son, J. Nutrition, 26, 673-685 (1943). 



904 J. C. Hammond and H. M. Harshaw, Poultry Sci., 20, 437-444 (1941). 



905 M. Rubin and H. R. Bird, Science, 103, 584-586 (1946). 



906 H. W. Josephs, Am. J. Diseases Children, 67, 33^3 (1944). 



907 J. A. Toomey and R. A. Morissette, Am. J. Diseases Children, 73, 473-480 (1947). 



