Albertine Donker

Chapter 2 76 CONCLUSIONS Knowledge on systemic and cellular iron homeostasis has greatly improved during the last decades, but many questions remain on the physiology of iron regulation in childhood. Our recent study in healthy children indicate that serum hepcidin relative to indicators of body iron is age dependent, suggesting a changing set point regarding systemic iron homeostasis during childhood. However, understanding of the optimal iron status for the different iron-demanding tissues is limited. Also mechanisms underlying the human body prioritorization and distribution of iron between the erythoblasts in the bone marrow, the brain and other iron-dependent organs systems during the different phases of development from fetus to adult are largely unknown. In order to get more insight into these processes, adequate assessment of iron status of the various iron-consuming organs in the developing child, and especially the central nervous system, is paramount, but appropriate (noninvasive) biomarkers are lacking until now. In this review we identified several knowledge gaps (summarized in Table 3 ). When these gaps have been succesfully addressed, the newly acquired insights will contribute to the development of clinical guidelines on a balanced iron supply and on the accurate diagnosis and treatment of iron disorders of the growing and developing child. For now, the limited understanding of iron physiology of childhood hampers the diagnosis and management of both acquired iron disorders as ID (anemia), anemia of inflammation or iron loading due to ineffective erythropoiesis and also anemias due to genetic disorders of iron metabolism.