If a two-and-a-half-year-old baby’s growth and development are within the normal range after a physical examination, and the trace element test is not abnormal, there is no need to supplement anything special. A normal diet, a balanced nutrition, and more outdoor activities will do. If your baby has calcium, iron or zinc deficiency in the trace element test, you need to treat it according to the doctor’s prescription, relying only on food supplementation will not achieve the purpose of treatment. Two and a half year old babies are most often suffering from low calcium due to vitamin D deficiency. Some children also have a partial diet and love colds, which indicates a possible zinc deficiency. Therefore, it is important to have a richer diet, with more vegetables, fruits, etc. If there is a zinc deficiency, it must be treated promptly. This is because zinc deficiency can lead to a low immune system, which can lead to respiratory and digestive tract infections.