The study guide is committed to provide current information about the human body protection against acute and chronic ionizing radiation. The study guide concerns the issues on applying radioprotective chemical agents and natural food items to increase the body resistance against the ionizing radiation in unfavourable environment as well as in the course of radiation therapy. Special attention is paid to the novel conception of radiation protection nutrition. This study guide is designed in accordance with the Curriculum of Radiation Medicine and Radiology to meet the academic, professional needs of medical interns and medical residents of higher medical establishments. It is intended for use by delivering the course of Radiation Medicine and Radiology to medical students.