Zinc requirements: assessment and population needs

Reliable estimates of zinc requirements have assumed greater priority as the global public health importance of preventing zinc deficiency has gained increasing recognition. On a global public health basis, our first most evident goal is reliable estimates of average population requirements. Despite expectations of rapid advances towards simpler and more sophisticated strategies, estimations of zinc requirements continue to depend on a factorial approach. Since the Dietary Reference Intakes (DRIs) were published, there have been important advances in techniques for the factorial approach but also confusion resulting from the subsequent publication of conflicting 'international' estimates. The reasons for these differences have now been fully elucidated, removing an obstruction to continuing progress and refinements of our knowledge base. A key advance has been the development and validation of a model that can be simply applied to determine the inhibitory effects of phytate on zinc absorption. Better understanding of maternal and young child zinc requirements continues to present a challenge of special importance.