What substance can decrease the bioavailability of non-heme iron?

The substance that can decrease the bioavailability of non-heme iron is calcium. Non-heme iron, which is found primarily in plant-based foods, has lower bioavailability compared to heme iron from animal sources. Calcium competes with non-heme iron for absorption in the intestines; when consumed together, high amounts of calcium can inhibit the uptake of iron. This is particularly significant during meals that contain both calcium-rich foods (like dairy) and non-heme iron sources (like leafy greens or legumes).

The other substances listed also interact with iron absorption in different ways. For instance, vitamin C actually enhances the absorption of non-heme iron, while phosphates can be a double-edged sword; they may have a negligible effect compared to calcium's stronger inhibitory role. Fiber can bind to minerals, including iron, but its effect is not as pronounced as that of calcium. Understanding these dynamics is crucial for optimizing iron intake, especially for those relying on non-heme sources.