Vitamin A deficiency and its consequences: a field guide to detection and control / Vitamin A deficiency and its consequences: a field guide to detection and control

ABSTRACT

Ocular manifestations of vitamin A deficiency, particularly night blindness, have been recognized since antiguity. Animal research and clinical observations early in the twentieth century indicated that vitamin A was important for numerous bodily functions animals and humans deficient in vitamin A grew poorly, suffered more persistent or severe infections, and subsequently developed characteristic ocular problems termed "xerophthalmia" or "dry eye". By the early 1940s these readily apparent eye signs had been eliminated from wealthier countries through dietary interventions. In developing countries today, however, at least 5-10 million children developed xerophthalmia every year, of whom between a quarter and a half a million go blind