Iron-ascorbate complex

Iron-ascorbate complexes are chemical entities formed in the gastrointestinal lumen when ascorbic acid (Vitamin C) interacts with dietary or supplemental iron (PubMed, 1984). These complexes play a crucial role in human nutrition by enhancing the bioavailability of non-heme iron, which is otherwise poorly soluble at the neutral to alkaline pH of the small intestine (NIH, 2022). Ascorbate acts as both a reducing agent, converting ferric iron (Fe3+) to the absorbable ferrous state (Fe2+), and as a chelating agent that maintains iron solubility as it moves from the acidic environment of the stomach to the more alkaline duodenum (PubMed, 2014). By preventing the formation of insoluble iron hydroxides and phytate-iron complexes, these ascorbate-iron species ensure that iron remains available for transport into enterocytes via the divalent metal transporter 1 (DMT1) (StatPearls, 2023). While therapeutically beneficial for treating iron deficiency anemia, the formation of these complexes can also promote the generation of reactive oxygen species through the Fenton reaction, potentially leading to localized oxidative damage in the gut mucosa (PubMed, 2014).

Other names

Ascorbate–iron complexFerrous ascorbateVitamin C-iron complexFerric-ascorbate complexIron(II) ascorbate

The complex enhances iron absorption by reducing ferric iron (Fe3+) to the more soluble ferrous form (Fe2+) and by forming a soluble chelate that prevents iron from precipitating at the alkaline pH of the duodenum, thereby maintaining its availability for transport by the divalent metal transporter 1 (DMT1) (PubMed, 2014; StatPearls, 2023).