The same is likely to be true in humans. Pregnant adult women need an extra 400 milligrams of calcium daily. That's about 50 percent more than recommended for women 25 and older. Nearly all of the extra calcium goes into the baby's bones. If there is not enough calcium in the mother's diet, the fetus may draw calcium from the mother's bones.
Nature also helps supply the extra calcium needed in pregnancy by improving calcium absorption.
Less is lost in urine and feces, and passage of calcium through the placenta to the fetus is facilitated. A pregnant woman needs three or more servings of milk or other dairy products a day to get 1,200 milligrams of calcium. Sometimes calcium supplements are recommended by a woman's doctor. But pregnant women should not take calcium supplements such as bone meal and dolomite. FDA surveys have shown that some bone meal and dolomite products contain substantial amounts of lead.