Iron is one of the most important macroelements in the body, which takes part in oxidation-reduction processes, and bioenergetics, and is a part of a number of enzymes. Iron deficiency is associated with food, pregnancy, fetal development, and some diseases. First of all, iron deficiency is established in iron-deficiency anemia, in addition to violations of biochemical indicators, immunological shifts and changes in the activity of vital organs and systems. The purpose of the study was to analyze the properties of iron and its preparations and their effects on the body. Materials and methods. On the topic of the study, a search and analysis of scientific literature was conducted in such databases as PubMed, Google Scholar, Scopus. Results and discussion. Iron reserves in the body are 3–6 g, the daily requirement is 20–30 mg. The need for iron increases in diseases with an increase in cardiac output, an increase in temperature, which requires taking drugs for oral and parenteral administration. In addition, if it is necessary to replenish iron reserves, it is recommended to take extracts from plants that contain it, such as common apricot (fruit pulp), blueberry fruits, beet roots, and common peach fruits. At the same time, it should be noted that iron can be in the oxidizing form of Fe2+ and the reduced form of Fe3+. It was determined that changes in iron metabolism and transport occur in pregnant women, which, in turn, is associated with changes in endothelial protective function. In modern methodological recommendations for the treatment of chronic heart failure, iron preparations are also included in the list of mandatory drugs, because in this condition, in addition to iron deficiency, disorders of the functions of the cardiovascular system have been found. A decrease in iron content has also been determined in various hypoxic conditions. Next they showed changes in iron metabolism in infectious diseases, such as COVID-19, tuberculosis, and HIV infection. In recent years, changes in iron content in neurodegenerative diseases have been noticed. Today, there are oral and parenteral iron preparations, but research is underway to create iron preparations that may have a more targeted effect and less toxicity. Conclusion. The current state of iron research in the functioning of vital organs and the occurrence of diseases presents scientists and clinicians with the task of involving new experimental and clinical methods to expand the understanding of the role of iron in pathobiochemical mechanisms, in pathological conditions, as well as the search for new approaches to treatment