The role of iron in the human body is as follows: 1, synthesis of hemoglobin: iron is an important component of hemoglobin in red blood cells, iron deficiency will reduce the amount of hemoglobin synthesized by red blood cells, which will make the volume of red blood cells become smaller, the oxygen-carrying capacity decreases, forming iron deficiency anemia, the patient will appear easy fatigue, dizziness, headache, blurred vision, rapid heartbeat, shortness of breath, easy infection, decreased appetite and other symptoms; 2, composition of myoglobin: iron is also a component of myoglobin in muscle, which can bind and store oxygen to provide energy for muscle activity; 3, participate in the synthesis of cytochrome enzymes and catalase: so that redox reactions in the body can be carried out normally; 4, other roles: to maintain the normal function of the immune system, participate in the metabolism of vitamin A and other trace elements.