Why do pregnant women need calcium supplements? After pregnancy, the fetus needs a large amount of calcium to form tissues such as teeth, bones, and muscles. If the calcium intake in the body of pregnant women is insufficient, it will be taken from bone reserves, leading to osteoporosis in pregnant women, which will have adverse effects on the health of pregnant women and fetuses. Therefore, getting enough calcium is crucial. The best way to supplement calcium for pregnant women is through food and medicine. Foods rich in calcium include milk, tofu, seaweed, etc.