[Zinc in human nutrition: physiological needs and bioavailability]

The zinc is one of basic essential trace-elements in human nutrition. The problem of the determination of zinc requirements in man is discussed in view of an appearance of adaptation to various levels of this trace element in a diet and degree of its bioavailability in basic kinds of foodstuff. The problem of evaluation of zinc bioavailability is highlighted from the positions of zinc absorption mechanisms based on the research data which have been obtained in model systems and in vivo in human and laboratory animals.