Vitamin A deficiency and its consequences
A field guide to their detection and control - Third edition
Ocular manisfestation of vitamin A deficiency, particularly night blindness, have been recognized since antiquity. Animal reseach 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 severrre 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 develop xerophthalmia every year, of whom between a quarter and a half a million go blind.
Recent data indicate that mortality rates are also increased among children with even mild vitamin A deficiency and that, in many areas, enhance vitamin A intake can reduce the risk of mortality from childhood infections by up to 54%. It is estimated that the deaths of at least one million children would be prevented each year if vitamin A status were improved.
The first edition of this manual was published in 1978 to meet the need for a practical guide for use by clinicians, nurses, and public health officials concerned with preventing xerophthalmia. The second edition, which appeared in 1982, reflected advances in understanding of the overall problem. Since then, the extension and further refinement of knowledge about the importance of vitamin A in the broader realm of child health and survival have made it necessary to revise and expand the manual. This greater understanding, combined with growing commitment by governments, enhances the feasibility of achieving the declared goal of eliminating vitamin A deficiency as a significant public health problem by the start of the next millennium.