METABOLISM OF CAItOTENOIDS AND VITAMINS A 561 



Table 6 



The Effect of Supplementary Vitamin A 

 ON THE Composition of the Milk Fat of Cows" 



" Data from H. J. Deuel, Jr., L. F. Hallman, C. Johnston, and F. Mattson, /. Nutri- 

 tion, 23, 567-579(1942). 



'' 0.6 ng. of /3-carotene calculated as equal to one l.U. 



suppressive effect of massive doses of vitamin A on carotenoid metabolism, 

 the reader is referred to page 447. 



When large doses of vitamin A were taken by women during the last 

 trimester of pregnancy, and during lactation, the vitamin A content of the 

 milk produced was increased. -°^ Thus, the total vitamin A in the colos- 

 trum of women who had received doses of vitamin A by mouth at several 

 levels for the three months preceding parturition amounted to the follow- 

 ing (I.U./IOO ml.): l.U. group, 424; 50,000 l.U. group, 747; 100,000 

 l.U. group, 1037; and 200,000 l.U. group, 1,177. The maximum level of 

 vitamin A was noted in milk from a woman in the fourth group; the total 

 vitamin A amounted to 2,160 I.U./IOO ml. milk. In the samples of milk, 

 which were collected at intervals over a period of sixty-one days after the 

 start of the lactation period, the concentrations of vitamin A in the same 

 four groups (as I.U./IOO ml.) were respectively as follows: 281, 344, 885, 

 718. Although there was a marked decrease in milk carotene as the period 

 of lactation progressed, there was no evidence of a suppression of the ca- 

 rotenoid content in the milk, such as had previously been demonstrated in 

 the cow, following a massive vitamin A intake. Sobel and associates*^* 



8^5 A. E. Sobel, A. Rosenberg, and B. Kramer, Am. J. Diseases Children, 80, 932-943 

 (1950). 



