In 2016, the Editorial Board of the Chinese Journal of Pediatrics, the Pediatric Health Care Group of the Chinese Medical Association, and the Neonatal Group of the Chinese Medical Association, Pediatrics Branch, jointly published the Recommendations for Post-discharge Feeding of Preterm, Low Birth Weight Infants, which stated that because both fat-soluble and water-soluble vitamins in human milk are difficult to meet the needs of preterm infants to catch up on growth, especially vitamin A (VA) and vitamin D (VD). Therefore, the recommendation emphasizes that preterm and low birth weight infants should be supplemented with VD 800-1000 IU/d immediately after birth and 400 IU/d after 3 months of age until 2 years of age, while the recommended intake of VA for preterm infants is 1332-3330 IU/(kg?d), which can be supplemented at the lower limit after discharge from the hospital. Not only preterm and low birth weight infants have serious vitamin A and D deficiencies, but epidemiological surveys in recent years have shown that vitamin A and D deficiencies are common among infants and children in China. VA in children under 5 years of age in poor rural areas of six western provinces of China is a severe deficiency, and the proportion of vitamin A deficiency (VAD) in hospitalized newborns in the Children’s Hospital of Chongqing Medical University is as high as 96.4%; the lowest serum vitamin A in the 0-1 year old group and the lowest 25-(OH)D in the 7-14 year old group in the resident Beijing urban area; the detection rate of VAD in all examined young children is 43.84% and the detection rate of VD deficiency is The detection rate of VAD was 43.84% and the detection rate of VD deficiency was 80.17% in all examined children. Most studies suggest that retinol is mainly transmitted to the fetus through the placenta during late pregnancy, so the physiological requirements of VA should be supplemented during mid- to late pregnancy and continued to be given to newborns after delivery. Infants and young children grow and develop rapidly, but their diet is relatively homogeneous and they do not get as much nutrients from food as adults. The VA content of infants and toddlers is low, which makes it difficult to meet the growth and development needs. In addition, infants and young children have limited stomach capacity and low intake of complementary foods, while carotenoids, which have low absorption and conversion rates, can only be absorbed in the presence of lipids. Therefore, a daily preventive dose of vitamin AD can effectively supplement the lack of vitamins A and D in the diet, maintain the normal functioning of physiological functions and promote healthy growth of infants and young children.