There are many reasons why it is difficult for children to fall asleep, such as lack of vitamin D, too much food before going to sleep, too much activity before going to bed. 1. Lack of vitamin D: due to the lack of vitamin D and calcium in the child’s body, resulting in increased excitability of the central nervous system, it is more difficult to go to sleep, may also be accompanied by waking up during sleep, abnormal crying, etc., usually recommended more sunshine, vitamin D and calcium supplementation, can gradually improve. 2. Eat too much to sleep: usually eat too much, resulting in indigestion, food accumulation, causing abdominal pain, bloating, it will be difficult to fall asleep, it is recommended not to give the child too much to eat before going to bed, usually pay attention to the regularity of the diet. 3. Too much activity before going to bed: some children are still playing before bedtime, keep running, so lying in the nest, active cells did not stop, still in the state of excitement, so it will lead to difficult to fall asleep, it is recommended that children do not over-excitement before bedtime. If the difficulty in falling asleep is not relieved, it is recommended to go to the hospital for examination.