The Relation of the Inorganic Constituents of a Ration to the Production of Ophthalmia in Rats

In 1922 McCollum, Simmonds, and Becker (1) described the production of an ophthalmia in rats on diets containing, what they thought to be, sufficient amounts of vitamin A. They believed that the ophthalmia was due to an improper balance of the inorganic constituents of the ration because their animals developed the ophthalmia if they fed their Salt Mixture 20, but not if they fed, instead, their Salt Mixture 185.In a second paper (2) these same investigators attempted to correlate the amount of vitamin B in the ration with the development of the sore eyes.In still more recent publications Simmonds, Becker, and McCollum(3) believe that they have shown a connection between the assimilation of iron and the reproductive factor, or vitamin E, both of which are associated in some unexplained manner with the eye trouble.They claim that the ferrous sulfate used in Salt Mixture 20 does not furnish the needed iron as well as the ferric citrate used in Salt Mixture 185, but if liberal amounts of vitamin E are present the ferrous iron is assimilated properly.Mori (4) has shown by microscopical studies on the animals that the eye lesions are identical with those of the xerophthalmia resulting from a vitamin A deficiency.Hopkins (5) has demonstrated that vitamin A is rather easily destroyed by oxidation.It is a well known fact that iron salts are good oxidative catalysts and especially at room or only slightly elevated temperatures.Karczag (6) has studied the effect of various inorganic salts on the speed of oxidative reactions.Of the salts investigated he found that the ferrous compounds had the 139