Does ageing affect zinc homeostasis and dietary requirements?
Dietary intakes of zinc are lower in the elderly because of reduced energy requirements, and it is not clear whether ageing impacts on adaptive homeostatic mechanisms, namely absorptive efficiency and endogenous losses in the GI tract. Physiological requirements for zinc are unlikely to change significantly, but there are several attributes of ageing that may affect aspects of zinc metabolism (e.g. changes in gut structure and function, disease states, chronic inflammation, epigenetic changes in genes that express zinc-related proteins and drug regimens) that are worthy of further investigation. There is, as yet, no information on the effects of ageing on zinc transporters, and there are no sensitive and specific measures of zinc status, therefore dietary recommendations for zinc have been derived from factorial calculations using information on zinc absorption and loss, and estimates of dietary bioavailability.
