U. S. DEPAETMEXT OF AGPJCULTUEE, 



cod-liver oil extensively as a food fat in the relief work with children 

 in Vienna after the war. The success of this makes it clear that cod- 

 liver oil can be relied on for such a purpose whenever circumstances 

 make this desirable. 



Many experimental studies of cod-liver oil have been reported in 

 medical literature. Some of the most interesting are those dealing 

 with its iodin content, which Andres, quoted by Lewkowitsch, 

 reports as 0.02 for pale oil and 0.03 per cent ^ for yellow oil, and to 

 which its therapeutic value has been attributed hj some. 



Osborne and Mendel ® first noted the remarkable potency of cod- 

 liver oil in vitamin A. More recently Zilva and Miura have shown 

 by new quantitative methods that crude cod-liver oil is in some cases 

 two hundred and fifty times as potent as butter fat and refined cod- 

 liver oil many times superior to butter in this respect.'^ This has 

 naturall}^ aroused much interest in the relation between its vitamin 

 content and its therapeutic value. Such investigations, together with 

 its successful use in the treatment of malnutrition in Vienna, can 

 hardly fail to bring about a more general use of cod-liver oil as 

 food fat. 



It is interesting to note that cod-liver oil has been studied in 

 animal feeding, specifically its effect on milk production when used 

 as a supplement to other fat in the ration of dairy cows. Hart, 

 Steenbock, and Hoppert report® that the daily addition of from 

 5 to 10 cubic centimeters of cod-liver oil to the diet of dry and milk- 

 ing goats consistently changed negative calcium balances to positive, 

 showing that some factor affecting calcium assimilation is present 

 in cod-liver oil. 



The digestibility of cod-liver oil by man has been studied by 

 Wells,'' who fed 100 grams per dsij to human subjects and found that 

 it was well assimilated. No significant difference was noted between 

 the emulsified and the unemulsified oil, the coefficients of digestibility 

 being respectively 96 and 97 per cent. Judging by the results ob- 

 tained, the cod-liver oil slightly increased the thoroughness of diges- 

 tion of the other fats present in the experimental ration. 



In the experiments made in this laboratory no difficulty was experi- 

 enced in feeding the cod-liver oil, the flavor being well masked by the 

 caramel and vanilla extract used in the cornstarch pudding which 

 served as a A^ehicle for the fat. The results of four experiments are 

 summarized in Table 1. 



s Chemical Technology and Analysis of Oil, Fats, and Waxes. 1909, 4 ed., vol. 2, 

 p. 361. 



«Jour. Biol. Chem., 17 (1914), No. 3, pp. 401-408. 

 ■^ Lancet [London], 200 (1921), No. 5085, p. 323. 

 * Jour. Biol. Chem.,, 48 (1921), pp. 33-50. 

 ' Brit. Med. Jour. No. 2181 (1902), pp. 1222-1224. 



