The recommended daily allowance for calcium is 500 mg for children aged one to three years. Parents can calculate whether their child’s calcium intake meets the Recommended Daily Intake (RDI) by looking at the foods consumed daily to assess the need for additional calcium supplementation. The ideal calcium intake can be achieved through: (1) diet, calcium-rich foods such as milk, bone broth, shrimp, fish, soy products, egg yolk, sesame paste, cabbage, celery, etc.; (2) calcium-fortified foods; (3) calcium supplements (calcium tablets). Calcium supplements are best from calcium-rich foods or calcium-fortified foods. Tofu and fish stewed together, shrimp skin chopped fried eggs, tomatoes and eggs fried together, cooking fish or ribs put some vinegar, can make the absorption and utilization of calcium greatly improved. Eat less high-salt, high-oil, high-protein diet, and less high-phosphorus foods such as soft drinks and colas. The former increases the excretion of calcium, and the latter hinders the absorption of calcium. Consider calcium supplements only if the diet is really unable to achieve adequate calcium intake. Surveys show that the calcium in the diet of infants and children aged 1-3 years in China still does not meet the required amount. To prevent calcium deficiency, the correct approach is: vitamin D supplementation + calcium supplementation. Because, in general, the effect of calcium supplementation alone is also not good, calcium supplementation with vitamin D at the same time, in order to facilitate calcium absorption. Sources of vitamin D: one, sunbathing, sunbathing not through the glass window, the sun’s ultraviolet rays can rarely penetrate the glass window. Also, try to expose as much skin as possible to increase skin synthesis of vitamin D. Second, oral concentrated cod liver oil, if calcium deficiency is obvious also need quantitative intramuscular injection of vitamin D3. supplementation VD and calcium supplements should generally continue until the age of 2 to 2 1/2 years. As children are growing and developing, parents pay special attention to their children’s health, worrying about stunted growth due to malnutrition and calcium deficiency. However, improper supplementation can be counterproductive, so parents should try to use special preparations for children and pay attention to the correct usage and dosage when supplementing their children with various nutrients. Excessive calcium supplementation in children can cause hypercalciuria, which increases the chance of forming stones in the urinary system; premature calcification of bones, premature closure of epiphysis, which affects the development of long bones and limits the final height; excessive calcium concentration in blood, which causes calcium to be deposited in internal organs or tissues, such as deposition around the cornea will affect vision, deposition on the heart valves will affect heart function, deposition on the walls of blood vessels will aggravate vascular sclerosis, etc. Excessive intake of vitamin D and increased calcium absorption in children will lead to hypercalcemia, manifested by indifferent expression, dry skin, vomiting, excessive drinking and urination, weight loss, etc. Children with suspected rickets or calcium deficiency should take calcium and vitamin D supplements under the guidance of a doctor. In addition, scientific research shows that calcium supplements alone cannot improve children’s height growth, and the so-called “eat calcium supplements to grow taller” advertising campaign lacks scientific basis. Calcium supplements alone will take a long time to increase the mineral content or bone density of children’s bones, and the cost is very high, which is a huge expense for most families. The best way to improve calcium nutrition in children is to increase the intake of milk and milk products, with a minimum daily intake of 500 ml of dairy for young children.