Calcium shots can have side effects such as hypercalcemia, nausea and vomiting. Clinically, calcium injections are mainly used to treat calcium deficiency, acute calcium loss, allergic diseases and so on. Calcium injection is injected intravenously, which can easily cause unstable levels of calcium ions in the body and even hypercalcemia. If calcium is injected too quickly it will lead to localized pain as well as cardiac arrhythmia, and some patients will also have gastrointestinal reactions, such as nausea and vomiting, abdominal distension, etc. Therefore, it is generally not recommended to take calcium injections. If calcium deficiency occurs, calcium can be supplemented through dietary therapy, such as milk and so on. At the same time, under the guidance of the doctor, you can also take oral medication to supplement calcium, such as calcium gluconate, calcium carbonate and so on. At the same time, calcium supplementation must be supplemented with vitamin D. Vitamin D is needed for calcium absorption, and calcium balance is also affected by vitamin D. When the patient has a calcium deficiency, it is recommended that the patient take calcium supplements under the guidance of a doctor, and not blindly use medication, so as not to cause adverse effects.