Trace elements for children include iron, iodine, zinc and copper, etc. Their testing needs to be analyzed specifically, e.g. zinc is usually tested for serum zinc levels, and iodine levels are judged by urine iodine concentration, etc. Trace elements in the human body include iron, iodine, zinc, copper, magnesium and selenium, etc. They are closely related to the growth and development of children. Iron, zinc and iodine deficiencies are more common in childhood. Micronutrient testing needs to be analyzed in relation to a specific element and cannot be standardized. For zinc, serum zinc is usually considered to be a reliable laboratory indicator, but lacks sensitivity. Serum zinc levels can remain normal in mild to moderate zinc deficiencies, and therefore need to be analyzed in the context of clinical specifics, such as dietary imbalances and other factors. Iodine levels are usually determined by thyroid ultrasound and thyroid stimulating hormone, and urinary iodine concentration is used to determine the iodine nutritional status of the population. Iron levels are determined by serum ferritin, serum iron and other indicators.