Vitamin A status of children as determined by dark adaptation

Abstract

Summary The purpose of this investigation was to determine the frequency with which vitamin A deficiency is encountered in children. In view of the fact that vitamin A deficiency brings about an elevation in the final rod threshold, i.e., the minimum intensity of light observed by the subject after complete dark adaptation, we made use of the final rod threshold level as a criterion of vitamin A deficiency. Accordingly, the final rod threshold was determined in 144 children ranging in age from 6 to 12 years. Sixteen of these children were private patients, whereas the remainder were observed either in the wards or in the Outpatient Department at Bellevue Hospital. Forty-two children had rheumatic fever, fourteen had pneumonia, six had active tuberculosis, and the remainder were suffering from one of the following conditions: upper respiratory infection, lung abscess, bronchiectasis, Hodgkin's disease, diabetes, renal calculus, malformation of the ureter, malnutrition, sickle cell anemia, dysentery, hemophilia, vaginitis, and asthma. Dark adaptation tests revealed normal threshold values in all but one instance. The sole exception was in a child who, because of abdominal pain, had been placed on a rigorous diet which was low in vitamin A. Administration of 120,000 units of vitamin A in the form of percomorph-liver oil brought about a fall of the threshold to a normal value in thirty-five minutes. The effect of this enormous dose lasted twenty days, at the end of which time the threshold again reached an abnormally high level. The provitamin, carotene (120,000 units) was then given, and a prompt response was again noted, the threshold returning to normal in thirty-two minutes. This child was then placed on a regular diet, and repeated tests over a period of several months have revealed normal values. The results of this investigation indicate that vitamin A deficiency, as judged by dark adaptation, is an uncommon disorder in children in New York City.