Diagnosis and Treatment of Iron Deficiency and Iron Deficiency Anemia in Children and Adolescents: Recommendations of the Polish Pediatric Society, the Polish Society of Pediatric Oncology and Hematology, the Polish Society of Neonatology, and the Po

<b>Background/Objectives.</b> Iron deficiency is one of the most common nutritional deficiencies worldwide and is the leading cause of anemia in the pediatric population (microcytic, hypochromic anemia due to iron deficiency). Moreover, untreated iron deficiency can lead to various systemic consequences and can disrupt the child's development. <b>Methods/Results.</b> Therefore, a team of experts from the Polish Pediatric Society, the Polish Society of Pediatric Oncology and Hematology, the Polish Neonatology Society, and the Polish Society of Family Medicine, based on a review of the current literature, their own clinical experience, and critical discussion, has developed updated guidelines for the diagnosis, prevention, and treatment of iron deficiency in children from birth to 18 years of age. These recommendations apply to the general population and do not take into account the specifics of individual conditions and diseases.