Babies often sleep less, may be caused by physiological reasons, but also may be vitamin D deficiency, parasitic infection and other pathological factors. 1. Physiological factors: the child’s physical sleep is less, or the child is more excited before bedtime, in the long run can lead to the baby often sleep less. 2. Vitamin D deficiency: these children have increased nervous excitability, difficulty in sleeping, and easy to wake up, usually accompanied by night sweats, bone deformation and other symptoms. 3. Parasite infection: Parasites are also an important cause of poor sleep in children. Parasites in the intestinal tract and outside the intestines will produce irritation phenomenon, affecting the child’s sleep. There are other reasons why babies often sleep less, such as indigestion. If physiological factors are excluded, it is recommended to consult a doctor to find out the cause of the problem and treat it under the doctor’s guidance.