It is recommended that pregnant women start to take calcium supplements after the 5th month of mid-pregnancy, with a recommended increase of 200mg/d of calcium and 15g/d of protein. After the 5th month of pregnancy, the intake of calcium by the mother increases day by day due to the peak growth and development of the fetus, especially the rapid development of the skeleton. If the pregnant woman still maintains the original amount of supplementation, it may cause intrauterine development of the fetus to be limited or cause symptoms of maternal calcium deficiency, such as lower limb convulsions. Pregnant women can take calcium supplements through food and medicine. Preferred food-based calcium supplementation, milk is the best food source of calcium, and for pregnant women who gain weight too fast during pregnancy, you can choose low-fat milk, which is not excessive weight gain but also supplementation of suitable calcium content. In addition, it is recommended that pregnant women reach a level of at least 300g/d of milk after the fifth month of pregnancy, and after the seventh month of late pregnancy, they should supplement an additional 400g/d of milk to reach a level of at least 500g/d of milk, so as to safeguard the calcium needs of fetal bone development.