 Standard approaches are not suitable for assessing the pharmacokinetics of iron supplements due to the ubiquity of endogenous iron, its compartmentalized sites of action, and the complexity of the iron metabolism. The primary site of action of iron is the erythrocyte, and unlike conventional drugs, there is no drug receptor interaction. It takes approximately three to four weeks for the formation of new erythrocytes, so serum iron levels and AUC are unsuitable for assessing iron utilization. Oral iron supplements can be administered intravenously in the form of polynuclear iron, three hydroxide complexes with carbohydrate ligands or orally as iron, two ferrous salts or iron, three ferric complexes. Several methods have been used to measure the pharmacodynamics of iron after oral administration, including quantifying iron uptake from radio-label preparations by the whole body or the erythrocytes, calculating total iron transfer based on known elimination rates and the intrinsic reactivity of individual preparations, measuring. This article was authored by Susanna Burkhardt and Peter Geisser. We are article.tv, links in the description below.