There are many reasons why children have gray hair, generally may include genetic factors, nutritional levels, mental factors and so on. 1. Genetic factors: generally speaking, if the parents have gray hair phenomenon, the child will have a greater chance of white hair, do not have to worry too much, relax, maintain a cheerful mood. 2. Nutritional level: small children with gray hair and their own nutritional level also has a certain relationship, when the child’s micronutrient level is low, such as copper, zinc, etc., easy to lead to the production of less melanin, white hair. It is recommended to go to the hospital to check the level of trace elements in the body, if found to be lacking in the corresponding trace elements, pay attention to supplement in the daily diet. 3. Mental factors: the existence of stress, mental tension, lack of sleep, etc., may lead to endocrine disorders in children, melanin secretion is insufficient, thus appearing white hair, should relax, maintain good habits.