Physiological functions: ① participation in oxygen transport and tissue respiration; ② Maintain normal hematopoietic function; ③ Participate in other important functions: A is related to maintaining normal immune function; B Iron deficiency can increase the infectivity of the body, hinder microbial reproduction, reduce the bactericidal ability of white blood cells and damage the function of lymphocytes. Excessive iron can promote the growth of bacteria, which is not conducive to resisting infection. Will reduce the function of iron-containing enzymes; C iron deficiency can cause cell dysfunction; D iron is related to anti-lipid peroxidation.
The reasons affecting iron absorption are as follows: ① The absorption of iron by the body is related to the existing form of iron in food, and iron in diet can be divided into heme iron and non-heme iron. ② Heme iron mainly exists in animal food, which is not affected by phytate and oxalate, and is directly absorbed by intestinal mucosal epithelial cells, so the absorption rate is high. Non-heme iron mainly exists in plant foods, which is influenced by phytate, oxalate, carbonate and phosphate, and its absorption rate is low. ③ Amino acids such as cystine, lysine and histidine, lactose and vitamin C can promote the absorption of iron; ④ Due to growth, menstruation, pregnancy and other reasons, the body's demand for iron increases, which can also promote the absorption of iron.
Ischemia in vivo is divided into three stages: the first stage is iron reduction, iron storage reduction, serum iron concentration reduction, and no clinical symptoms. The second stage is the iron deficiency stage of erythropoiesis, that is, the concentration of serum iron decreases, the concentration of transferrin decreases and the concentration of free protoporphyrin increases, but the concentration of hemoglobin has not yet fallen to the anemia standard. The third stage is iron deficiency anemia, when hemoglobin and hematocrit are decreased, accompanied by clinical symptoms of iron deficiency anemia.
AI value: adult male 15mg/d, female 20mg/d, first trimester 15mg/d, second trimester and lactating mother 25mg/d, third trimester 35 mg/d, and UL 42mg/d.
Animal food is rich in iron, lean meat, eggs, animal whole blood, poultry, fish and so on. The iron content in vegetables, milk and dairy products is not high.