Under normal circumstances, you can feel the bone gap on the top of the baby’s skull, and generally the bone gap needs to be completely closed around two years old, but if you feel the bone gap on the baby’s head is wider and larger, you should pay attention to the following factors: 1. pay attention to the child’s head circumference measurement, pay attention to exclude the child’s bone gap enlargement due to hydrocephalus or high intracranial pressure; 2. pay attention to the child’s bone density, blood vitamin D, pay attention to the child may be due to vitamin D deficiency, or calcium supplementation and lead to the bone gap enlargement, this time we should pay attention to timely and adequate supplementation of calcium and vitamin D, as well as regular monitoring.