The causes of hair standing up in children include the following: first, due to genetic factors. If one or both of the child’s parents have hair that is hard and stands up, the child’s hair will also stand up due to genetic factors. Secondly, the symptoms are caused by calcium deficiency in children. If children usually have less sun exposure and do not take vitamin D supplements on time, they will develop vitamin D deficiency rickets, in which case they will have a calcium deficiency in their bodies, which will cause their hair to stand up. Finally, if the child has malnutrition anemia, will also cause hair erection, you can give children to eat more fish, shrimp, beef, duck blood, etc..