Discuss dietary factors that influence zinc absorption. Identify good food sources of zinc.

Absorption of zinc is variable and influenced by a number of factors. High non-heme iron intakes can inhibit zinc absorption, which is a primary concern with iron supplements, particularly during pregnancy and lactation. High intakes of heme iron appear to have no effect on zinc absorption. Although calcium is known to inhibit zinc absorption in animals, this has not been demonstrated to occur in humans. The phytates and fibre found in whole grains and beans strongly inhibit iron absorption. In contrast, dietary protein enhances zinc absorption, with animal-based proteins increasing the absorption of zinc to a much greater extent than plant-based proteins.