XEROPHTHALMIA IN FOWLS FED ON POLISHED RICE 
AND ITS CLINICAL IMPORTANCE 
By Drs. L. E. GUERRERO and I. CONCEPCION 
In 1909 Stepp for the first time deduced from his experi- 
mental work on rats that certain fatty substances, or some 
substances soluble in fats, were very essential to the mainte- 
nance of life and the growth of the organism. In 1913 Mc- 
Collum and Davis, and Osborne and Mendel demonstrated that, 
in addition to proteins, carbohydrates, fats, and mineral salts, 
certain accessories, or complementary substances, were neces- 
sary for the proper nourishment and growth of the body. 
These accessories are two in number, and McCollum and Kenedy 
named them provisionally “fat soluble A” and ‘‘water soluble B”’. 
Fat soluble A exists widely in animal and plant tissues. It 
has been found in butter fat, egg fat, beef fat, cod liver oil, 
the testes of codfish, the kidneys, liver and liver oil of pigs, 
in oleomargarine, fish fats, fish oils, dried unsweetened con- 
densed milk, corn, wheat, rye, oats, plant leaves, cotton flour, 
cottonseed oil, flax seeds and millet seeds, soy beans, peas, and 
bananas. It is absent or present only in insignificant amounts in 
lard, pig’s heart, pancreas, thymus and adrenals, olive oil, almond 
oil, linseed oil, corn oil, and in the oils of sunflower, soy beans, 
wheat, cottonseed, nut margarine, vegetable margarine, white 
beans, barley, and potatoes. It can be isolated from the animal 
tissues with ether, chloroform, benzine, and acetone. However, 
in order to isolate it from plants it is necessary to treat the 
mother substances with these solvents, and then extract it from 
the residue with hot alcohol. 
McCollum and his coworkers have shown, by numerous ex- 
periments on rats fed on different mixtures of various purified 
food products, that the absence, or insufficiency, of fat soluble 
A from the food caused in these animals marked general mal- 
nutrition and edema of the eyes which, on prolonged feeding, 
terminated in complete blindness and in the death of the ani- 
mals. They have often averted and overcome xerophthalmia by 
placing the animals on any of the above-mentioned foods rich 
in fat soluble A. 
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