Calcium deficiency in pregnant women may be characterized by leg cramps, weakness, muscle aches and pains. In the middle and late stages of pregnancy, the growth and development of the fetus requires a large amount of calcium, if the pregnant woman does not make timely calcium supplementation will lead to calcium deficiency. Calcium deficiency in pregnant women leads to leg cramps which is a relatively common phenomenon, and may also lead to back pain. Calcium deficiency in pregnant women can cause osteoporosis, and may also lead to weakness, leg pain on both sides and other hazards. Calcium deficiency in pregnant women may also affect the development of the fetus, fetal calcium deficiency during pregnancy may lead to neonatal rickets. Therefore, pregnant women during pregnancy should take calcium supplements in time, go to the hospital on time for maternity checkups, timely detection of physical conditions during pregnancy, and give appropriate treatment.