Comparative Absorption and Bioavailability of Various Chemical Forms of Zinc in Humans: A Narrative Review.

Zinc is an essential micronutrient that is needed for numerous critical health functions in the body. It is estimated that 17 to 20% of the global population is at risk for zinc deficiency, with certain groups at higher risk. The provision of supplemental zinc is a convenient and effective option for treating zinc deficiency and maintaining healthy levels of zinc. Several zinc salts are available for use in supplements. However, little information is available comparing the absorption and bioavailability of these different chemical forms of zinc. In this narrative review, we provide an overview of zinc absorption and bioavailability, discuss indicators of zinc status and risk factors for zinc deficiency, and review clinical studies comparing the absorption and bioavailability of different chemical forms of zinc in humans. This review of the clinical evidence suggests that zinc glycinate and zinc gluconate are better absorbed than other forms of zinc.