Zinc and the Synthesis of Zinc Binding Proteins (Protocol B)

Methods to assess the dietary zinc status of individual humans or populations are lacking. The study is a three period observational study of biomarkers of zinc status before, during and after zinc depletion. The entire dietary study will take 24 days composed of three parts: * Dietary Acclimation (Phase 1): 7 days * Dietary Zinc Restriction (Phase 2): 10 days * Dietary Zinc Repletion (Phase 3): 7 days The dietary treatments and all blood draws will be carried out in the General Clinical Research Center (GCRC) at University of Florida. Previous research from has shown that both metallothionein gene expression and specific zinc transporter genes in blood leukocyte subsets are directly proportional to dietary zinc intake. By using cDNA array analysis and quantitative PCR technology with blood RNA, those genes most sensitive to zinc nutrition will be identified for the purpose of developing zinc status assessment methods on how zinc functions in human biology. Additionally, buccal mucosal cells will be collected in the GCRC by using swabs, i.e., in a noninvasive manner, to further characterize the expression pattern of the genes under study. This method has the potential for nutrition studies in the field (international nutrition, etc).