Dietary non-heme iron (Fe)

Dietary non-heme iron refers to the inorganic iron found in plant-based foods and fortified products, primarily existing in the ferric (Fe3+) state within the gastrointestinal lumen (NIH, 2023). It serves as a critical substrate for systemic iron homeostasis, providing the necessary iron for hemoglobin synthesis and cellular enzymes (StatPearls, 2023). Absorption occurs mainly in the duodenum, where ferric iron must be reduced to the ferrous (Fe2+) state by duodenal cytochrome B before transport into enterocytes via divalent metal transporter 1 (PubMed, 2019). In clinical practice, this luminal iron is a target for various pharmacological agents; for instance, ascorbic acid is used to enhance its absorption by promoting its reduced state (NIH, 2023). Conversely, proton pump inhibitors can decrease its bioavailability by increasing gastric pH, which reduces iron solubility (PubMed, 2015). Excessive luminal iron is associated with gastrointestinal toxicity, as unabsorbed iron can catalyze the formation of reactive oxygen species through Fenton chemistry (PubMed, 2019). This oxidative stress can damage the intestinal mucosa and negatively impact the composition of the gut microbiota. Therefore, therapeutic strategies often focus on balancing luminal iron levels to treat deficiency while avoiding the adverse effects of iron overload.

Other names

Inorganic ironLuminal ironNon-heme ironFerric ironFerrous iron

Chelation of luminal iron to prevent absorption, redox reduction of ferric iron to ferrous iron to enhance uptake, and pH-mediated modulation of solubility.