The human body can take calcium supplements every day through ingestion, however, due to the higher calcium requirement of pregnant women, they may need additional calcium supplements, which need to be regulated and reasonable under the guidance of a doctor. Calcium supplementation during pregnancy up to several months varies from person to person, usually starting from the middle of pregnancy until the end of delivery, but can be discontinued around 8 months of pregnancy if premature placentation occurs in late pregnancy. For pregnant women who breastfeed after delivery, it is recommended to continue calcium supplementation during breastfeeding. At around 5 months of gestation into the middle of pregnancy, until the birth of the fetus or even 6 months of life are in a period of rapid bone development, therefore, the demand for calcium for pregnant women and the fetus is high and needs to be supplemented in appropriate amounts. Pregnant women can clarify the length of the fetus’ main limb bones, femur, tibia and head circumference through obstetric ultrasound, and adjust the amount of calcium supplementation appropriately according to the doctor’s recommendation. Pregnant women are advised to consume foods with high calcium content such as milk, lean meat, eggs, fish and shrimp, kelp, nori and other foods in moderation while taking calcium supplements medically, and more sunshine can supplement vitamin D, which is beneficial to calcium absorption.