Surveys of the Nutrition of Populations. The Vitamin A Nutrition of a Rural Population in Middle Tennessee (Part 3)

Abstract

There was a deficient dietary intake of vit. A in a large proportion of the population. This was not accompanied by a correspondingly high incidence of symptoms or physical signs of a deficiency. However, the tests of dark adaptation and the conc, of vit. A in the blood indicated a degree of deficiency somewhat comparable to that suggested by the dietary intake. The manifestations of a deficiency vary at different levels of intensity and duration and according to the definitions of the deficiency. Neither the deficiency of intake nor the objective manifestations of a deficient nutrition were distributed equally among the various age and sex and racial groups.