The six trace elements are checked for trace elements, which usually include zinc, iron, copper, magnesium, calcium and lead. When zinc is deficient, it can affect the child’s nervous system development and affect the digestive function. Common foods that contain more zinc include meat, liver, eggs, and animal offal. Iron deficiency can lead to iron deficiency anemia, and foods that are usually supplemented with iron include meat, liver, fish, and poultry. Copper is richer in fruits, nuts, liver, and meat; magnesium is richer in cereals, honey, green leafy vegetables, seafood, and spinach; calcium is richer in milk, dairy products, legumes, and shrimp. Frequent testing of trace elements is a reference value for growing children and pregnant women.