Zinc is an essential trace element necessary for the functioning of approximately 100 different enzymes in the body. It plays a vital role in many biological processes, such as the maintenance of protein structure, the regulation of gene expression and the metabolism of hormones. Zinc is abundant in red meats, certain seafood and whole grains, and many breakfast cereals are fortified with zinc. The proportion of dietary zinc absorbed is determined by the amount of zinc already present in the body, with higher absorption occurring when zinc status is low 1.
Zinc is regarded as relatively safe and generally well tolerated when taken at recommended doses. The U.S. Food and Drug Administration (FDA) has established a Reference Daily Intake (RDI) of 15 mg zinc for adults and children 4 or more years of age (21CFR101.9). RDIs are a set of dietary references for essential vitamins and minerals that are considered amounts sufficient to meet the daily requirements of healthy individuals. RDIs serve as the basis for calculating the percent daily value (%DV) amounts found on dietary supplement and food labels.