Iron is an essential component of human cells, it has hematopoietic functions, participates in the production of hemoglobin and the synthesis of cytochromes and various enzymes, and promotes growth. Iron also plays a role in transporting and carrying nutrients in the blood, and if iron deficiency occurs, iron deficiency anemia can occur, which can also cause a decrease in immune function and metabolic disorders. However, if iron supplementation is excessive, poisoning can also occur, mainly manifested by nausea, vomiting, acute abdominal pain, diarrhea and fever. Iron poisoning is more common in children, and once it occurs, tissue necrosis can occur, making it easy to develop cirrhosis, diabetes, brown pigmentation of the skin, and heart failure, so nothing should be eaten in excess.