Stable Natural Iron Complex Micronutrient Powder for Enhanced Cellular Uptake

Iron deficiency anemia (IDA) is a persistent global health challenge, particularly in low- and middle-income countries, necessitating effective iron fortification strategies. In this study, we developed FeC-4-1, a novel iron complex composed of ferrous sulfate, vitamin C (VC), and histidine, to enhance iron stability, cellular iron uptake, and compatibility with food matrices. FeC-4-1 exhibited high stability across a broad pH range (3–12). Under simulated gastric conditions, FeC-4-1 released nearly 100% of its iron and VC within 10 min, ensuring efficient cellular iron uptake. FeC-4-1 also demonstrated superior oxidation resistance compared to FeSO₄, exhibiting 2.5-fold lower color change in polyphenol-rich banana milk after 2-h treatment. Long-term storage studies revealed that FeC-4-1 maintained 60% of its initial total iron content with the ferrous iron fraction remaining at ∼80% after 12 months, indicating minimal oxidation over time. Bioaccessibility studies following an established INFOGEST protocol showed that FeC-4-1 provided about 2-fold higher bioaccessible iron compared to FeSO₄ under room temperature conditions. In addition, FeC-4-1 resulted in approximately a 3.2-fold increase in total intracellular iron compared to FeSO₄ in Caco-2 cells. Sensory evaluation results demonstrated that FeC-4-1 fortification at 16 mg per serving (50% RDA of iron) in bouillon soup did not alter flavor or mouthfeel. These findings suggest that FeC-4-1 is a technically feasible and effective iron fortificant, offering enhanced stability, bioaccessibility, and consumer acceptability for in-home iron fortification.