Human zinc deficiency

The objective of this paper is to provide a current overview of the signifi cance of zinc in human nutrition. To achieve this, the following issues are addressed: (I) the biochemistry and biology of zinc in the context of thei r relevance to zinc in human nutrition and to our understanding of the comp lexity and practical importance of human zinc deficiency; (2) the history o f our understanding of human zinc deficiency with an emphasis both on its b revity and on notable recent progress; (3) the clinical spectrum of severe zinc deficiency; (4) the lack of ideal biomarkers for milder zinc deficienc y states, with the consequent dependence on randomized, placebo-controlled intervention studies to ascertain their prevalence and clinical consequence s, including growth delay, diarrhea, pneumonia, other infections, disturbed neuropsychological performance and abnormalities of fetal development; (5) the public health significance of human zinc deficiency in the developing world; (6) reasons for concern and unanswered questions about zinc nutritur e in the United States; (7) the need for better understanding of human zinc metabolism and homeostasis (including its limitations) at a molecular, cel lular, organ-system and whole body level and of factors that affect zinc bi oavailability; and (8) potential strategies for the prevention and manageme nt of human zinc deficiency, This review concludes with an emphasis on the immediate need for expanded research in directions that have become increas ingly well demarcated and impelling as a result of recent progress, which i s summarized in this overview.