Trace elements refer to elements that contain less than 0.01% in the human body. Among them, about 14 elements are essential for human life activities, which we call essential trace elements, such as zinc, copper, iron, manganese, iodine, molybdenum and fluorine. These elements are involved in various physiological activities and metabolic processes of human body, so their role is especially important for children who are in the period of vigorous growth and development. If there is a deficiency of essential trace elements in children for some reasons, it will not only directly affect the growth and development of children, but also lead to the occurrence of some diseases, which will have a serious impact on children’s health. So, how to prevent the lack of trace elements in children’s bodies to prevent hair yellowish? 1, breastfeeding: for infants and young children within 1 week of age, as far as possible, the use of breastfeeding. So far, breast milk is still the most suitable natural nutrition for infants that is irreplaceable. It not only contains rich and diverse nutrients, enzymes and antibodies, but also the trace elements contained in it are most easily absorbed by children. 2. Develop good eating habits: do not be partial or picky about food. The spectrum of trace elements contained in various foods is different, and the intake of a variety of foods can ensure adequate intake of trace elements and promote the body’s absorption of trace elements. If children are partial and picky eaters and have a single diet, it will undoubtedly lead to the lack of trace elements in the body. 3, encourage eating coarse food: some parents mistakenly believe that the food given to children, the finer the better. The process of food processing will lose a lot of trace elements, and the finer the processing, the more loss. Therefore, often give children to eat refined food, it is possible to cause a number of micronutrient deficiencies.