Should Chinese infants and toddlers be supplemented with vitamin D alone or with AD? This view is still controversial among some pediatricians, pediatricians and parents. To address this issue, we need to analyze the data from multiple perspectives. Vitamin A deficiency in Chinese infants and young children Vitamin A deficiency is one of the four major nutritional deficiencies announced by the World Health Organization, and the rate of vitamin A deficiency in developing countries is much higher than that in developed countries in Europe and the United States, which is related to different races, dietary structure, economic conditions, environmental and climatic factors. Vitamin A Deficiency Survey of Children Under 6 Years of Age in China shows that the rate of vitamin A deficiency and subclinical vitamin A deficiency among children aged 0-6 years in China is more than 50%, and the rate among infants younger than 6 months is even higher than 80%, therefore, China is a country with moderate vitamin A deficiency. The Prevention and Control Program for Subclinical Vitamin A Deficiency states that for vitamin A supplementation intervention for children with subclinical vitamin A deficiency, any one of the following two methods can be used: Ordinary oral method: infants and young children aged 0-3 years are given vitamin A orally at a daily dose of 1,500 to 2,000 IU (infants less than 1 year of age receive 1,500 IU, and children 1-3 years of age receive 2,000 IU). This method is the vitamin A supplementation method routinely used in our country, daily supplementation, high security, more suitable for our national conditions. Large-dose surprise method: oral vitamin A2 times in 1 year, each time 100,000-200,000 IU (100,000 IU for infants under 1 year old, 200,000 IU for children 1-3 years old), with an interval of 6 months. This method is low-cost, easy to operate, and is the vitamin A supplementation method currently adopted by many developing countries internationally. Current situation of vitamin D deficiency in Chinese infants and young children Although the incidence of vitamin D deficiency rickets in China has decreased, the prevalence rate of infants and young children in urban and rural areas is still as high as 25%. Inadequate vitamin D intake is common among infants and young children in China. Among them, infants, children and adolescents are the high-risk groups for vitamin D deficiency. The Recommendations for the Prevention and Control of Vitamin D Deficiency Rickets state that infants 2 weeks after birth should receive vitamin D 400U/d daily until 2 years of age. For high-risk groups such as preterm infants, low birth weight infants, and twin births, vitamin D supplementation should be started immediately after birth at 800-1000 U/d, and then changed to 400 U/d after 3 months. The American Academy of Pediatrics recommends that vitamin D supplementation should be started immediately after birth and continued through puberty. The synergistic effect of vitamin AD supplementation Adequate vitamin D is a prerequisite to ensure the absorption of calcium from food and the growth and development of bones, and deficiency can lead to rickets. The lack of vitamin A will cause bone tissue degeneration, affecting calcium absorption, so that the amount of bone and bone density decline, leading to delayed development of infants and young children’s bones, and at the same time will affect the development of teeth. AD with supplementation, together to promote children’s bone calcium absorption, promote the growth and development of bones and teeth. Vitamin A helps to maintain the integrity of the respiratory mucosa, enhance the defense ability of the epithelial tissue, and can improve the function of immune cells and promote antibody production. Vitamin D is also important for activating the body’s immune system. Children’s recurrent respiratory infections and other diseases and the body’s vitamin A, vitamin D levels decline. AD with supplementation, synergistic enhancement of infant resistance, reduce the incidence of infection. In addition, vitamin AD also has the ability to prevent iron-deficiency anemia, reduce the incidence of measles, reduce the risk of diabetes, tumors, hypertension and other diseases, affecting the health of the whole organism. How to supplement vitamin AD in China and abroad? Vitamin D deficiency is a globally widespread problem, so countries have different supplementation programs, even developed countries have clear supplementation recommendations, take the United States as an example, in November 2008 released a new “prevention of vitamin D deficiency and rickets in infants, young children and adolescents,” the recommended amount of the original 200IU/d increased to 400IU/d, the recommended age of supplementation including all infants ( starting a few days after birth), children and adolescents. Vitamin A deficiency varies from country to country, for certain developed countries in Europe and the United States, due to dietary structure, racial differences and other factors, the problem of vitamin A deficiency is not prominent, and there is no need to routinely supplement vitamin A. For the existence of vitamin A deficiency in the country, in order to save costs and facilitate the operation of the World Health Organization to give centralized high-dose supplementation of vitamin A for prevention of the recommendation, that is, each dose of 100,000 – 200,000 units every 4 to 6 months of dosing. Compared to single large-dose supplementation, daily small-dose supplementation is safer and more effective. China’s overall vitamin A intake for infants and children is low, and the country is considered to be moderately deficient in vitamin A. Therefore, it is important for Chinese infants and children to take a small daily supplement. Therefore, daily preventive vitamin A supplementation is essential for Chinese infants and children. To summarize, Chinese infants and children with vitamin A and vitamin D deficiencies have outstanding problems, and should be routinely supplemented with prophylactic vitamin AD preparations, which is recommended to start on the 15th day of life and continue to be supplemented until the age of 3 weeks. Recommendations: Vitamin A (retinol) and vitamin D (cholecalciferol) are included in the World Health Organization Standard List of Essential Medicines for Children (2nd edition), which belongs to the 27th category – vitamins and minerals. Vitamin AD capsules are included in the Chinese National Formulary (Children’s Edition) and are recommended to be taken by children under 1 year of age in the size of 1500IU of vitamin A and 500IU of vitamin D per capsule; and by children over 1 year of age in the size of 2000IU of vitamin A and 700IU of vitamin D per capsule. Used for the prevention and treatment of vitamin A and vitamin D deficiencies, such as night blindness, dry eye, rickets, osteochondritis dissecans. Take orally, 1 capsule once a day.