A one-year-old baby tossing and turning in the middle of the night may be due to insufficient vitamin D or calcium, and may also be related to the external environment, indigestion and other factors. 1. Babies are in a period of rapid physical development, if the usual intake of vitamin D or calcium is insufficient, it will lead to calcium deficiency. Calcium deficiency often causes increased excitability of the nerves and muscles, which can lead to tossing and turning at night. 2. The external environment when the baby sleeps will also have an impact on the baby, the baby’s central nervous system is in the developmental period, for the stimulation of the external environment is more sensitive. Too high a temperature or a noisy environment can cause a baby to toss and turn at night. 3. The baby’s gastrointestinal digestive function is poor, so eat too fast or eat too much will lead to indigestion, it is easy to cause discomfort at night and thus tossing and turning. Eating too little can also lead to hunger pangs and tossing and turning at night. When your baby is not feeling well, you should go to the hospital immediately.