Oyster-derived Zinc Exhibits Superior Anti-anemic Efficacy and Bioavailability Compared with Conventional Zinc Supplements

Abstract

Zinc is an essential trace element involved in numerous biological processes. Zinc bioavailability is a central issue in nutritional biochemistry; however, comparative evidence linking zinc source, intestinal absorption, and physiological efficacy remains limited. In this study, we compared the bioavailability and anti-anemic efficacy of zinc derived from oysters (Crassostrea gigas) with those of conventional zinc supplements. Using a phenylhydrazine-induced hemolytic anemia rat model, we demonstrate that oral supplementation with oyster-derived zinc effectively restores red blood cell counts. Selective chelation of zinc from oyster tissue using 1,10-phenanthroline abolished this effect, confirming zinc as the principal active component. Dose-response analysis identified a minimum effective dose of 2.1 mg Zn/rat/day for oyster-derived zinc, whereas a substantially higher dose of zinc sulfate (5.0 mg Zn/rat/day) was required to achieve comparable erythropoietic recovery. When equivalent zinc doses were administered, only oyster-derived zinc significantly increased plasma erythropoietin (EPO) levels and restored erythropoiesis. In vitro studies using simulated gastrointestinal digestion and Caco-2 cell transport assays revealed that oyster-derived zinc exhibits approximately two-fold higher bioavailability than inorganic zinc (zinc sulfate), organic zinc salts (zinc gluconate or zinc acetate), or peptide-bound zinc (polaprezinc). Collectively, these findings demonstrate that zinc delivered within a natural food matrix confers enhanced bioavailability and biological efficacy, highlighting oyster-derived zinc as a nutritionally advantageous source for alleviating zinc deficiency and correcting zinc-responsive anemia.