Baby sleep a shaking, mainly and lack of nutrients related, there is a situation is a normal physiological phenomenon. 1. lack of nutrients: when the baby lack of calcium or lack of vitamin D, there may be a body shaking situation, especially in sleep this situation is more obvious. 2. Physiological phenomenon: the baby in the small time the central nervous system of the brain is not fully developed, the cerebral cortex of the body’s control ability is relatively poor, so the baby will appear in the sleep of a shaking problem, which belongs to the normal physiological phenomenon. Baby sleep a shaking, there may also be other reasons, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, give targeted treatment or treatment.