As infants grow, their bodies require large amounts of calcium ions due to rapid physical development, and therefore calcium deficiency can result when lost or undersupplied. In general, infant calcium deficiency can be diagnosed through symptoms and clinical examination. I. What symptoms can determine the calcium deficiency in infants There are more symptoms of calcium deficiency in infants, which can be identified by the following symptoms: 1. mild calcium deficiency: manifested as sleeping, drinking milk and sweating a lot, easy to wake up, easy to jump, irritable, crying, occipital baldness, frequent cramps, etc.; 2. severe calcium deficiency: manifested as rickets, skeletal deformities, such as beaded chest, chicken chest, funnel chest, “X 2. Severe calcium deficiency: manifested as rickets, skeletal deformities, such as beaded chest, chicken chest, funnel chest, “X” leg, “O” leg, low muscle tone, backward motor function development, abnormal cerebral cortex development, indifferent expression, delayed language development, low immunity, and repeated colds. What tests can clarify calcium deficiency in infants Calcium deficiency in infants is often caused by vitamin D deficiency, which can be diagnosed by testing blood 25(OH)D3, calcium, phosphorus and alkaline phosphatase, and also by bone X-ray examination (bone density, bone epiphysis). How to supplement calcium deficiency in infants Calcium can be supplemented through the following ways: 1. indirectly through maternal supplementation: when breastfeeding, infants mostly take in nutrients through their mothers, so mothers should ensure a balanced diet, not picky and partial eating, and eat more calcium-rich foods; 2. direct supplementation: after 4 months of age, add high-calcium supplements in a timely manner, and at the same time, get more sunlight or take vitamin D supplements to facilitate the absorption of calcium in the body. If you need to supplement calcium through calcium supplements, pay attention not to eat with foods that affect the absorption of calcium. If the symptoms of calcium deficiency are more serious, you should go to the hospital for calcium supplementation under the guidance of a doctor.