A CLINICAL METHOD FOR DETERMINING MODERATE DEGREES OF VITAMIN A DEFICIENCY

Abstract

The accepted and easily recognized clinical evidences of vitamin A deprivation are associated only with marked degrees of vitamin A deficiency. Night blindness is one of these several clinical phenomena, but it is one that is not recognized by an ordinary routine examination and one that usually is considered only when the complaint is made by the patient. A routine test for night blindness probably would reveal many more cases than are now suspected. It might be expected also that a suitable method of examination would detect night blindness, which is present in such a mild degree that the afflicted individual is entirely unaware of its existence. Since the etiology of night blindness in these cases is presumably the same, regardless of its degree, it should be possible to detect even moderate deficiency of vitamin A by means of appropriate tests. Our purpose in this presentation is to show that