If you are pregnant or breastfeeding your newborn baby, you must receive the necessary amount of calcium and vitamin D. These nutrients are essential both for yourself and for your child’s developing skeleton. Do not forget that you are eating for two. If you do not take in as much calcium as required, your baby’s needs will be met by drawing calcium from your own bones.

If you are under the age of 19, you need 1300 mg of calcium and 400–800 international units (IU) of vitamin D daily. If you are over the age of 19, you need 1000 mg of calcium and 400–800 international units (IU) of vitamin D daily. Adequate intake of calcium and vitamin D during pregnancy is an excellent first step toward building healthy and strong bones for both you and your child.

Most studies show that although women lose part of their bone density during pregnancy, they usually regain it after delivery. In fact, multiple pregnancies, even more than 10, do not appear to lead to a predisposition to osteoporosis later in life. On the contrary, some studies suggest that multiple pregnancies may even protect against osteoporosis, a finding that is partly attributed to the high estrogen levels seen in highly fertile women.

As for women who become pregnant during adolescence, the situation is not clear. These young women usually have not yet reached their peak bone density. More research may be needed to determine whether pregnancy during adolescence affects later bone health.

Pregnancy-associated osteoporosis. Some women develop a form of transient osteoporosis during pregnancy. The causes of this form of the disease are unknown, and the mechanisms involved have not yet been fully understood. Nevertheless, it is very rare and usually resolves quickly after delivery.

Breastfeeding. Breastfeeding for 6–12 months after childbirth has important benefits for both mother and child. Like pregnancy, breastfeeding may also cause temporary bone loss. Within a short time after weaning, bone density recovers, and this does not appear to cause long-term harm to the health of the female skeleton. All pregnant and breastfeeding women should receive adequate amounts of calcium and vitamin D for themselves and for their child. Women who choose exclusive breastfeeding should consult their pediatrician about whether their baby should receive vitamin D supplements, especially if they do not get enough sunlight several times a week and do not eat fish.