The symptoms of zinc overdose include decreased resistance, memory loss and anemia, as follows: 1. Decreased resistance: Excessive blood zinc inhibits the phagocytosis and bactericidal effect of white blood cells, making the human body less resistant and vulnerable to pathogenic bacteria. 2. Decreased memory: For people who are not zinc deficient, additional supplementation may cause an excess of zinc in the body, which may cause metabolic disorders and even damage to the brain. 3. Anemia: Some parents mistakenly take zinc products as nutrients and give them to their babies in large quantities for a long time, not knowing that zinc oversupplementation can also be harmful, reducing the vitamin C and iron content in the body, inhibiting the absorption and utilization of iron, and easily causing and aggravating iron deficiency anemia.