Micronutrient deficiencies in children may lead to mental retardation, weakness of the limbs, iron-deficiency anemia, short stature and other symptoms. 1. Zinc deficiency: A deficiency of zinc can lead to significant mental retardation in children. 2. Lack of potassium: Children lacking potassium will lead to hypokalemia. Hypokalemia will lead to an increase in the absolute value of the resting potential of muscle tissues and a decrease in excitability, thus causing symptoms such as muscle weakness. 3. Lack of iron element: lack of iron element will lead to the synthesis of red blood cells obstacle, children will have iron deficiency anemia. 4. Lack of iodine: Lack of iodine will lead to impaired synthesis of thyroid hormones, resulting in short stature and lower intelligence than their peers. If any of the above symptoms occur, it is recommended to visit the hospital for micronutrient testing.