Zinc (ZN) is an essential trace element (micronutrient) and plays a vital role in several biological processes 1. ZN is released from food as free ions during digestion. Specific transport proteins facilitate the passage of ZN across cell membranes into circulation. 70% of circulatory ZN is bound to albumin 2. As ZN does not attain redox properties, it is capable of transportation around the biological systems without inducing oxidative damage, which can occur with other essential trace elements like copper 3.
Physiological Significance
ZN has a key role in growth, reproduction, sexual maturity and the immune system. ZN is vitally important in the functionality of >300 enzymes utilised in the stabilisation of DNA and gene expression 1. ZN can constitute strong, yet readily available flexible and exchangeable, complexes with organic molecules, enabling it to modify the three-dimensional structure of specific proteins, nucleic acids, and cellular membranes, thereby influencing the catalytic properties of many enzyme systems and intracellular signalling. ZN is associated with >50 metalloenzymes with a diverse range of functions and so ZN plays a central role in metabolism, differentiation and cellular growth 3.
Deficiency
Zinc deficiency has been identified as a malnutrition issue worldwide. ZN deficiency is more prevalent in areas of low animal consumption and high cereal consumption. It’s not that the diet is low in ZN but more so the bio-availability of ZN which plays a major role in its absorption.
Toxicity
As there are multiple sources of ZN in the environment, exposure to and toxicity from ZN are not uncommon.