Normal infant sleep time should be maintained within 14 hours, children with difficulty falling asleep, frequent awakening at night, consider calcium deficiency, gastrointestinal discomfort, teething, as well as large motor development during the period will be prone to poor sleep. Babies should be supplemented with vitamin d or vitamin ad after 15 days of life to promote calcium absorption, and preterm infants should be supplemented with 400-800 units per day within one week of birth. If vitamin D is deficient it can cause poor absorption of calcium. Calcium is an indicator of maintaining the stability of the nervous system, so when this value is not high, it is easy to produce the nerve, the excitability is higher causing sleep disorders. Gastrointestinal development in infants and young children is not very good. Dietary reasons, weather reasons may cause flatulence, which affects sleep. You need to give your child with probiotics to do exhaust exercises every day, rub the stomach clockwise, and take simethicone oil to relieve flatulence if necessary. The child’s gums are uncomfortable during teething, and the child is prone to frequent irritability at night, which usually lasts for about half a month. After the child appears to roll over, it is easy to have a bad night sleep, this is because his light sleep is getting more and more in the light sleep state, it will also repeat the daytime big movement, so it is easy to appear this kind of repeated irritability, this is just a process of the child, basically a year and a half after the age of can be relieved.