Often parents and friends say that their children do not sleep well, to check “calcium deficiency”, parents say “calcium deficiency” our doctors in medicine called “vitamin D deficiency rickets”, actually it is vitamin D deficiency, “calcium deficiency” is only one of the causes of poor sleep, in fact, there are many reasons why children sleep well. In fact, it is vitamin D deficiency, parents see “calcium deficiency” is only one of the causes of children’s poor sleep, in fact, there are many reasons why children do not sleep well. We all know that children’s sleep is very important to their growth and development, children’s sleep is affected by many factors, including internal and external factors. First: first of all, the intrinsic factors include whether the child is sick (such as fever, diarrhea, abdominal pain, asthma, skin allergies, etc.), the child’s own temperament characteristics (such as difficult to raise the type of temperament), poor sleep habits. Second: external factors, including the sleep environment and nurturing environment: crowded living environment, noise, too much light, too much sleep cover, cover too hot, or too cold will affect the child’s sleep, especially the temperature of the sleep environment is too large a change in the temperature of the sleep environment will significantly interfere with the child’s sleep, the optimal temperature of the sleep environment is 22-27 degrees Celsius. Children sleeping in the same bed with their parents can also significantly affect the child’s sleep. These children, especially those who are breastfed, may show intermittent and discontinuous sleep patterns at night, so it is best for the child to sleep in a separate bed from the parents. Poor parental response can also affect the child’s sleep, for example, if the child moves or cries, the parents immediately pick up the child, feed him/her, or take him/her to the toilet, which will also affect the child’s sleep. The family’s economic status, cultural background, parents’ education level, whether the parents’ relationship is harmonious, whether the mother is separated from the child, whether the parents live a regular life, etc. will affect the child’s sleep.