Evaluation of the Validity of a Novel Isotope Dilution Method to Assess the Iron Status and Its Changes in Swiss Women

Conventional indirect indicators of iron status, using serum and red blood cell biomarkers, are confounded by inflammation from common infections and are therefore of limited use in populations carrying a high burden of infection and inflammation, as for example women of reproductive age in malaria endemic areas in developing countries. Even without the confounding effect of inflammation, current markers of iron status are insensitive to small changes in dietary iron and do not allow to establish associations between dietary, lifestyle and genetic factors and iron balance. With a new method based on the dilution of a previously administered and equilibrated stable isotope signal, an accurate measurement of long-term oral iron balance and absorption is possible, allowing the estimation of iron requirements and potentially providing fundamental guidance for supplementation and fortification programs in both healthy and chronically inflamed/infected patients. In the current study the novel methodology will be validated in generally healthy subjects with low iron status. The technique will be used to assess dietary and lifestyle determinants of iron status and to compare the effect on iron balance and iron status of three distinct, commonly used iron interventions: food fortification with iron; oral iron supplementation, and intravenous iron infusion.