Vital Need of the Body for Certain Unsaturated Fatty Acids

As will be shown in the present communication, when rats are reared on complete diets, their body fats can be shown by direct feeding tests to contain appreciable amounts of the essential unsaturated fatty acids (vitamin F).As will also be shown, the vitally necessary substance is, however, either absent or greatly reduced in the carcass fat of rats reared on fat-free diets.To determine this, fats were isolated from the carcasses of rats maintained on different types of diets.Three diets' were used, stock Diets I and XIV and fat-free Diet 616.Adult female rats raised on these diets were ground up, their fats extracted with hot ethyl alcohol and ether, and converted to the methyl esters.