Beyond bioavailability: dual-source iron improves absorption and cellular handling.

Dual-source iron enhances intestinal absorption and cellular handling through complementary pathways. Schematic representation of the mechanisms underlying the improved performance of dual-source iron formulations containing both heme and non-heme iron. In the intestinal epithelium, heme iron is absorbed via heme carrier protein 1 (HCP1), while non-heme iron is taken up through divalent metal transporter 1 (DMT1), enabling the engagement of complementary uptake pathways. Following intestinal uptake, iron is efficiently processed within enterocytes, as indicated by increased ferritin-mediated intracellular storage and ferroportin-dependent export into the circulation. This coordinated handling supports improved systemic iron availability. Importantly, the combined engagement of these pathways is associated with preserved epithelial integrity, likely due to reduced levels of unabsorbed luminal iron. Overall, dual-source iron formulations integrate enhanced uptake and efficient intracellular processing with maintenance of intestinal barrier function, providing a mechanistic basis for improved iron handling.Illustration showing a dual-source iron supplement above a diagram of intestinal absorption. Heme iron enters through the HCP1 transporter, while non-heme iron enters through DMT1. Iron is stored as ferritin or released by ferroportin, supporting improved iron handling and epithelial integrity.