Baby sleeps during the day and does not sleep at night according to the specific reasons, you can change the child’s sleep pattern, reduce the time of daytime sleep, supplement vitamin D, etc., and gradually adjust. Babies who sleep during the day and do not sleep at night may have their days and nights reversed, so you can take your child outdoors during the day, and open the curtains indoors during the day to let your child feel the daytime, and reduce the amount of time spent sleeping during the day so that he or she can sleep better at night. If your baby is deficient in vitamin D, he or she may not sleep well at night so that he or she sleeps longer during the day, thus affecting his or her ability to sleep at night, and can be supplemented with vitamin D under the guidance of a doctor. However, it is important to be aware of the side effects of vitamin D, such as nausea, loss of appetite, and other adverse reactions. The baby sleeps during the day and does not sleep at night, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, to give targeted treatment or treatment.