Calcium supplementation should be started in the 4th month of pregnancy and can be continued until the birth of the fetus, and the amount of calcium supplementation should increase as pregnancy increases. During the first 4 months of pregnancy, the fetus grows slowly in the mother’s body and the daily dietary intake can meet the calcium needs of the pregnant woman and the fetus. In the middle and late stages of pregnancy, the fetal growth and development starts to accelerate, the simple food intake can no longer meet the fetal and maternal demand for calcium, so you need to start taking calcium supplements, and you can choose to take calcium tablets every morning after meals to reduce the intestinal stimulation. You should also take outdoor activities every day and get more sunlight to promote calcium absorption. In addition, care needs to be taken to avoid excessive calcium supplementation, which may lead to placental aging and reduced amniotic fluid. In addition to calcium supplements, you can also supplement calcium through diet by eating more lean meat, soy products, milk, etc. Calcium supplementation during pregnancy can also prevent the risk of hypertensive disorders during pregnancy.