DIGESTION, ETC. OF FAT-SOLUBLE VITAMINS 315 



or to rats 429 in jojoba seed oil, ethyl laurate, basking shark liver oil, cot- 

 tonseed oil, corn oil, castor oil, or mineral oil. The vitamin A absorption 

 as determined from the vitamin A content of the liver under these several 

 conditions is summarized for chickens in Table 8 and for rats in Table 9. 



Table 9 



Average Storage of Vitamin A in Livers of Vitamin A-Defictent Rats after 



Feeding of 9000 Units of Vitamin A in the Form of Alcohol, Acetate, or Natural 



Ester in Six Divided Doses with Several Diluent Oils" 



Jojoba 

 Castor seed 



Diluent oil Corn oil oil oil 



Oil fed per dose, ml 0.4;0.1 0.4 0.4 



Vitamin A concentration, units/nil 7,500; 30,000 7,500 7,500 



Units of vitamin A per liver after: 



Alcohol 2,990;2,920 2,720 2,660 



Acetate 3,250;3,530 2,740 2,610 



Ester 2,630; 3, 140 2,690 1,770 



Per cent vitamin A stored after: 



Alcohol 33.2;32.4 30.2 29.5 



Acetate 36.1;39.2 30.4 28.9 



Ester 29.2;34.9 29.9 19.7 



10 rats were used per group. 



" Data from E. F. Week and F. J. Sevigne, J. Nutrition, 89, 251-257 (1949). 



Vitamin A deposition in the livers of chickens, which is an index of rela- 

 tive absorption, would appear to be dependent upon the form of vitamin 

 A used, as well as upon the diluent oil. In all cases, the vitamin A deposi- 

 tion is lowest when the natural ester is fed. In general, vitamin A acetate 

 elicits a slightly lower response than does the free alcohol, but this condi- 

 tion is revised if the quantity of oil given with the vitamin is reduced to a 

 minimum. The amount of vitamin A deposited in the liver when the 

 vitamin was dissolved in corn, cottonseed, or jojoba oil was highest for 

 the alcohol form. When ethyl laurate or castor oil was the diluent, 

 slightly lower results were obtained for all types of vitamin A. How- 

 ever, when sardine oil, basking shark oil, or mineral oil was employed, 

 the vitamin A deposition was reduced to 50 to 60% of that obtained with 

 cottonseed oil. 428 



On the other hand, the greatest discrepancies caused by the several 

 diluent oils were noted in the experiments in which the natural ester was 

 used. In the case of jojoba oil tests at 2.0 ml. of diluent oil per feeding, the 

 vitamin A was only one-fourth as effective (as regards deposition) when 



429 E. F. Week and F. J. Sevigne, ./. Nutrition, 39, 251-257 (1949). 



