Zinc can maintain the normal immune function of human body. Zinc deficiency can make thymus and spleen atrophy, T cells decrease obviously, lymphocyte transformation rate is low, and cellular immune function is weakened, which is easy to lead to infectious diseases. Zinc is related to phagocytes. After acute infection, phagocytes can release endogenous cellular mediators (LEM) to transport zinc, iron and some amino acids to the liver, which is conducive to the synthesis and release of various "acute reactive globulins" by hepatocytes and strengthens the phagocytosis of white blood cells. Alkaline phosphatase is one of the enzymes containing zinc, and the activity of phagocytosis of alkaline phosphatase increases after acute infection. Zinc supplementation can enhance emergency response and improve immunity.