1. protein. Protein is the material basis of human immune function. If the intake is insufficient, it will affect tissue repair, reduce the local immunity of skin and mucosa, easily cause the reproduction and spread of pathogenic bacteria, and reduce the anti-infection ability. Protein is contained in many foods. In addition to common animal foods such as fish, shrimp, meat and eggs, protein is also found in plant foods such as rice, flour and soybeans. Protein in animal food (including protein in soybean and its products) is easier to be fully utilized by human body than plant protein.

2. vitamin a. Vitamin A plays an important role in the immune system. Once lacking, it can cause keratinization of respiratory, digestive, urinary and reproductive epithelial cells, which are easy to be invaded by bacteria and increase the risk of respiratory and intestinal infections. Foods rich in vitamin A are mainly animal livers, while plant foods can only provide carotenoids (which can be converted into vitamin A in the body). Carotenoids mainly exist in dark green or red and yellow vegetables and fruits, such as carrots, spinach, celery, mangoes and sweet potatoes.

3. Vitamin E Vitamin E is an antioxidant in the body and an effective immunomodulator, which can improve the anti-infection ability. Vitamin E supplementation can keep the immune system of the elderly working normally. The main sources of vitamin E include vegetable oil, nuts, beans and cereals.

In addition, vitamin C has antioxidant effect and is an essential vitamin for human immune system. Fresh vegetables and fruits are rich sources of vitamin C, such as fresh dates, green peppers, kiwis, spinach, hawthorn, citrus, grapefruit and strawberries. Iron. Iron deficiency is a common nutritional disease, which can lead to anemia and reduce anti-infection ability, especially for infants, pregnant women and lactating mothers. In order to supplement iron, we should eat some foods rich in heme iron, such as red meat, animal blood, animal internal organs, etc. At the same time, we should eat more foods rich in vitamin C and B vitamins, such as green leafy vegetables and green peppers. Zinc is a component of more than 65,438+000 enzymes in human body, which plays an important role in the development of immune system and the maintenance of normal immune function. Shellfish seafood, red meat and animal offal are good sources of zinc. Selenium is an essential trace element for human body and has a strong antioxidant effect. Selenium exists in almost all immune cells, and selenium supplementation can obviously improve the immunity of the body. Animal foods such as liver, kidney and seafood are good food sources of selenium.