Four-month-old babies can take medication if the doctor confirms the diagnosis of calcium deficiency. At the same time to check the trace elements, Diclo pediatric calcium carbonate D3 granules are effective. You can also give your baby calcium gluconate, so four-month-old babies need to go to the hospital in time if they have uncomfortable symptoms. In addition, more sunshine is also helpful, you can take the baby after 10:00 am sunshine. In addition, you can also give your baby more high vitamin and high protein diet. In severe cases, you need to inject vitamin D3 injection, as well as supplement zinc, iron and so on.