The baby’s day and night reversal may be caused by physiological factors, or may be caused by pathological factors such as vitamin D deficiency. General treatment can be taken, oral vitamin D drops and other medication to improve. 1. Physiological factors: babies sleep more during the day and less at night, which may lead to day and night reversal. Can be appropriate to wake up the baby during the day, and its interactive games, or increase the frequency of breastfeeding, to maintain the environment of normal light, no need to be particularly quiet; before going to bed at night need to turn off the lights, to maintain a quiet environment, so that the baby’s day and night reversal can be gradually adjusted. 2. Vitamin D deficiency: when the child has a vitamin D deficiency, it is easy to have night terrors, night sweats, crying, resulting in sleep disturbance, night sleep efficiency decreases, so that the daytime sleep more. At this time, oral vitamin D is needed to improve the baby’s symptoms. There are other reasons for your baby’s night and day reversals, so we recommend that you consult your doctor for a complete examination to find the cause of the problem, and then cooperate with your doctor for treatment if necessary. The above medication should be taken in accordance with the doctor’s prescription.