A nine-month-old baby with zinc deficiency can be supplemented in the following ways: 1. Dietary supplementation. Although zinc is important, the baby’s demand is not large. It can be supplemented by pork, pork liver, chicken liver, egg yolk, kelp, fish and shrimp, etc. 2.Medicinal supplementation. Zinc gluconate is organic zinc, which only has mild gastrointestinal discomfort and can be eliminated by taking it after meals. It can be dissolved in juice and fed to the baby.3. Zinc supplementation should be higher in summer than in winter and spring.4. Medication interference. Zinc supplementation should not be taken at the same time as tetracycline, penicillin, folic acid, etc. Secondly, the main sources of zinc are zinc-rich foods, animal liver, fish, milk, meat, shrimp skin, nori, sesame, etc. Various kinds of beans and nuts in plant foods contain more zinc, and vegetables such as cabbage, white radish, eggplant and bok choy contain more zinc, so you can give your baby some in moderation.