Fig. 1

Study design flowchart. We evaluated the effect of different zinc statuses on peripheral blood mononuclear cells (PBMC) CREMα protein as well as RNA expression and subsequent IL-2 production capacity. Overall zinc status was assessed by measuring serum as well as PBMC intracellular labile zinc and applying a zinc-specific food frequency questionnaire to estimate dietary zinc intake. In this study, we compared 23 young, healthy adults to 31 hospitalized geriatric inpatients, further dividing the latter into either zinc-adequate (ZA) or zinc-deficient (ZD). A total of 10 seniors that were previously classified as zinc-deficient by the means of serum zinc or zinc uptake received short-term zinc supplementation (ZS), of whom, after all experiments were repeated, 6 were considered zinc-adequate and 4 were still mildly zinc-deficient (dotted lines)