This review by Abbaspour, Hurrell, and Kelishadi discusses the importance of iron for human health, covering its role in various metabolic processes, such as oxygen transport, DNA synthesis, and electron transport. Iron deficiency and overload are common disorders that can lead to a wide range of diseases, including anemia and neurodegenerative conditions. The article reviews recent advancements in understanding iron metabolism and bioavailability, and highlights the current knowledge of human iron requirements and the causes and consequences of iron deficiency. It also explores strategies for preventing iron deficiency, including dietary diversification, supplementation, fortification, and biofortification. The review emphasizes the importance of iron in different life stages, particularly in children, adolescents, and women of reproductive age, who are at higher risk of iron deficiency. Additionally, it discusses the impact of iron deficiency on anemia and its various causes, such as kidney disease, pregnancy, poor nutrition, obesity, alcoholism, sickle cell anemia, thalassemia, and aplastic anemia.This review by Abbaspour, Hurrell, and Kelishadi discusses the importance of iron for human health, covering its role in various metabolic processes, such as oxygen transport, DNA synthesis, and electron transport. Iron deficiency and overload are common disorders that can lead to a wide range of diseases, including anemia and neurodegenerative conditions. The article reviews recent advancements in understanding iron metabolism and bioavailability, and highlights the current knowledge of human iron requirements and the causes and consequences of iron deficiency. It also explores strategies for preventing iron deficiency, including dietary diversification, supplementation, fortification, and biofortification. The review emphasizes the importance of iron in different life stages, particularly in children, adolescents, and women of reproductive age, who are at higher risk of iron deficiency. Additionally, it discusses the impact of iron deficiency on anemia and its various causes, such as kidney disease, pregnancy, poor nutrition, obesity, alcoholism, sickle cell anemia, thalassemia, and aplastic anemia.