Is zinc deficiency a public health problem?

Zinc is essential for all species. Human zinc deficiency related to diet was recognized 30 yr ago among adolescents in Iran and Egypt. Subsequent factorial calculations, balance studies, and tracer studies of bioavailability and turnover established the amounts of zinc needed for equilibrium and dietary factors that impair retention. Comparison of dietary intakes of zinc with requirements suggested many women and children are at risk of deficiency. Epidemiological studies associated low plasma levels of zinc with abnormal pregnancy outcomes and controlled intervention trials showed that zinc repletion improved pregnancy outcomes. Low iron nutriture, a common phenomenon in women, was shown to be associated with low zinc nutriture. Thus the hypothesis that zinc deficiency is a public health problem appears to be true.