Symptoms of zinc deficiency include: i. Slow growth, height 3-6cm lower than the same age group, weight 2-3kg lighter. ii. Low immunity, frequent colds and fevers, repeated respiratory infections such as tonsillitis, bronchitis, pneumonia, sweating, night sweats in bed, etc. iii. Third, white spots on nails, long barbs on fingers, map tongue. Fourth, vision problems, vision loss can easily lead to night vision difficulties, nearsightedness, farsightedness, astigmatism and so on. Skin damage, trauma wounds do not heal easily, prone to dermatitis, intractable eczema. Sixth, loss of appetite, picky eaters, anorexia, refusal to eat, general reduction in the amount of food, the child has no sense of hunger, do not take the initiative to eat. Seven, indiscriminate eating strange things, such as biting nails, clothing, chewing toys, eating hair, confetti, dirt, gravel and so on. VIII. Hyperactivity, slow reaction, poor concentration, poor learning ability.