Final answer:
Vitamin C is the nutrient that increases the absorption of non-heme iron by converting Fe3+ into the more soluble form Fe2+, aiding in its absorption in the digestive system.
Step-by-step explanation:
The nutrient that increases the absorption of non-heme iron by reducing ferric iron (Fe3+) to ferrous iron (Fe2+) is vitamin C. Non-heme iron is commonly found in plant foods and is less efficiently absorbed compared to heme iron from animal sources. Vitamin C (ascorbic acid) enhances non-heme iron absorption by converting Fe3+ to the more soluble Fe2+ state within the acidic environment of the stomach.
Various factors influence iron absorption from our diet. For instance, the presence of phytic acid and oxalic acid in foods can decrease iron absorption by forming insoluble compounds with iron. On the other hand, a diet low in these substances can increase iron absorption significantly. Iron supplementation in food uses forms like reduced iron, a fine metallic powder, which is then oxidized to Fe2+ in the digestive system for absorption. This process of fortification ensures sufficient iron intake, as iron is vital for many biological functions, including oxygen transport in hemoglobin and as a component of various enzymes.