FISH-LIVER OILS 



519 



Table 113. 



Annual Importations of Fish Livers and Vitamin-bearing Fish Liver 

 Oils into the United States, 1934-1948. 



' Halibut-liver oil. ^ Shark-body oil and shark-liver oil. 



Source: Foreign Commerce and Navigation of the United States, U. S. Department of 

 Commerce. 



by exploitation of the fisheries of several of the South and Central American 

 countries. 



International and U.S.P. Standards for Vitamin A 



Rosenberg (1942) lists the interrelationship of the various vitamin A units 

 used as follov^^s: 



"One I.U. (International Unit) = One U.S.P. unit; one I.U. = 0.6 microgram of pure 

 beta-carotene, m.p. 184° C, optically inactive, dissolved in coconut oil with addition of 

 hydroquinone; one I.U. = 1.5 to 2 Sherman units. 



"One g of U.S.P. cod-liver oil must contain at least 600 U.S.P. units of vitamin A. 

 (Since July 1, 1940, a minimum of 850 units per g is required.) 

 "One g of pure vitamin A contains 4,500,000 International Units. 

 "One Cod Liver Oil Unit (C.L.O. Unit) 



= 125 gamma ( 1 gamma = 10"^ g) of beta-carotene 



==208 U.S.P. units 



= 10 "Lovibond units" 



= 50 Lovibond units (Wolff) 



= 550 blue units ( Moore ) 



"In British practice, one International Unit of vitamin A is in effect defined by 

 1: 



E t "' 328 millimicrons 

 1 cm 



0.000625 



which is equivalent to the use of 1600 as conversion factor for the physical measurement 

 value. In the United States the conversion factor of 2000 is usually used instead of 1600." 



