Both pregnancy and breastfeeding cause changes in, and place extra demands on, women’s bodies. Some of these may affect their bones. The good news is that most women do not experience bone problems during pregnancy and breastfeeding. And if their bones are affected during these times, the problem often is corrected easily. Nevertheless, taking care of one’s bone health is especially important during pregnancy and breastfeeding, for the good health of both the mother and her baby.

During pregnancy, the baby growing in its mother’s womb needs plenty of calcium to develop its skeleton. This need is especially great during the last 3 months of pregnancy. If the mother doesn’t get enough calcium, her baby will draw what it needs from the mother’s bones. So, it is disconcerting that most women of childbearing years are not in the habit of getting enough calcium. Fortunately, pregnancy appears to help protect most women’s calcium reserves in several ways:

• Pregnant women absorb calcium from food and supplements better than women who are not pregnant. This is especially true during the last half of pregnancy, when the baby is growing quickly and has the greatest need for calcium.
• During pregnancy, women produce more estrogen, a hormone that protects bones.
• Any bone mass lost during pregnancy is typically restored within several months after the baby’s delivery (or several months after breastfeeding is stopped).

Some studies suggest that pregnancy may be good for bone health overall. Some evidence suggests that the more times a woman has been pregnant (for at least 28 weeks), the greater her bone density and the lower her risk of fracture.

In some cases, women develop osteoporosis during pregnancy or breastfeeding, although this is rare. Osteoporosis is bone loss that is serious enough to result in fragile bones and increased risk of fracture.

In many cases, women who develop osteoporosis during pregnancy or breastfeeding will recover lost bone after childbirth or after they stop breastfeeding. It is less clear whether teenage mothers can recover lost bone and go on to optimize their bone mass.

Teen pregnancy and bone health. Teenage mothers may be at especially high risk for bone loss during pregnancy and for osteoporosis later in life. Unlike older women, teenage mothers are still building much of their own total bone mass. The unborn baby’s need to develop its skeleton may compete with the young mother’s need for calcium to build her own bones, compromising her ability to achieve optimal bone mass that will help protect her from osteoporosis later in life. To minimize any bone loss, pregnant teens should be especially careful to get enough calcium during pregnancy and breastfeeding.

Breastfeeding also affects a mother’s bones. Studies have shown that women often lose 3 to 5 percent of their bone mass during breastfeeding, although they recover it rapidly after weaning. This bone loss may be caused by the growing baby’s increased need for calcium, which is drawn from the mother’s bones. The amount of calcium the mother needs depends on the amount of breast milk produced and how long breastfeeding continues. Women also may lose bone mass during breastfeeding because they’re producing less estrogen, which is the hormone that protects bones. The good news is that, like bone lost during pregnancy, bone lost during breastfeeding is usually recovered within a few months after breastfeeding ends.

Taking care of your bones is important throughout life, including before, during, and after pregnancy and breastfeeding. A balanced diet with adequate calcium, regular exercise, and a healthy lifestyle are good for mothers and their babies.

Calcium. Although this mineral is important throughout your lifetime, your body’s demand for calcium is greater during pregnancy and breastfeeding because both you and your baby need it. The National Academy of Sciences recommends that women who are pregnant or breastfeeding consume 1,000 mg (milligrams) of calcium each day. For pregnant teens, the recommended intake is even higher: 1,300 mg of calcium a day.

Good sources of calcium include:

• Low-fat dairy products, such as milk, yogurt, cheese, and ice cream.
• Dark green, leafy vegetables, such as broccoli, collard greens, and bok choy.
• Canned sardines and salmon with bones.
• Tofu, almonds, and corn tortillas.
• Foods fortified with calcium, such as orange juice, cereals, and breads.

In addition, your doctor probably will prescribe a vitamin and mineral supplement to take during pregnancy and breastfeeding to ensure that you get enough of this important mineral.

Exercise. Like muscles, bones respond to exercise by becoming stronger. Regular exercise, especially weight-bearing and resistance activities, are important. Examples of weight-bearing exercise include walking, climbing stairs, and dancing. Resistance exercises – such as lifting weights – can also make bones stronger. Exercising during pregnancy can benefit your health in other ways, too. According to the American College of Obstetricians and Gynecologists, being active during pregnancy can:

• Help reduce backaches, constipation, bloating, and swelling.
• Help prevent or treat gestational diabetes (a type of diabetes that starts during pregnancy).
• Increase energy.
• Improve mood.
• Improve posture.
• Promote muscle tone, strength, and endurance.
• Help you sleep better.
• Help you get back in shape after your baby is born.

Before you begin or resume an exercise program, talk to your doctor about your plans.

Healthy lifestyle. Smoking is bad for your baby, bad for your bones, and bad for your heart and lungs. If you smoke, talk to your doctor about quitting. He or she can suggest resources to help you. Alcohol also is bad for pregnant and breastfeeding women and their babies, and excess alcohol is bad for bones. Be sure to follow your doctor’s orders to avoid alcohol during this important time.

Calcium

To keep your bones strong, eat foods rich in calcium. Some people have trouble digesting the lactose found in milk and other dairy foods, including cheese and yogurt. Most supermarkets sell lactose-reduced dairy foods. Many nondairy foods are also calcium-rich.

Calcium-Rich Foods

Vitamin D

Vitamin D helps your body absorb calcium. As you grow older, your need for vitamin D goes up. Vitamin D is made by your skin when you are in the sun. For many, especially seniors, getting enough vitamin D from sunlight is not practical. Almost all milk and some other foods are fortified with vitamin D. If you are not getting enough calcium and vitamin D in your diet, supplements can be bone savers.

Your body needs calcium and vitamin D.

The foods we eat contain a variety of vitamins, minerals, and other important nutrients that help keep our bodies healthy. We need to get enough of two nutrients in particular, calcium and vitamin D, to help keep our bones strong.

What does calcium do for our bones?

Calcium is a mineral. Our bodies contain many different minerals, such as iron and magnesium, but the most abundant mineral in the body is calcium.

Also, our bones are partly made of calcium salts (mixtures of calcium with other minerals), especially calcium phosphate. Calcium phosphate hardens and strengthens bone.

Our bodies cannot make calcium. We need to get calcium from foods and drinks, and supplements when needed, to build strong bones and teeth and to keep them healthy. Healthy bones are less likely to break if we fall.

What happens to our bones without enough calcium?

Calcium does more than build strong bone. It also helps our muscles, heart, and nerves work properly.

If we do not get enough calcium in our diets, our body takes the calcium we need from our bones. Over time, this process makes bones weaker and raises the risk of osteoporosis. Osteoporosis is a disease that makes bones weak and brittle, and people with osteoporosis have a higher risk of fractures (broken bones).

How much calcium do we need?

The amount of calcium each person needs depends on their age and sex. Table 1 lists how much calcium people need every day to keep their bones strong and healthy.

Table 1

Source: National Institutes of Health Office of Dietary Supplements

What foods have calcium?

The best food sources of calcium are milk and other dairy products, like cheese and yogurt. Other food sources of calcium include:

• Fish (such as salmon and tuna).
• Leafy green vegetables (such as kale and turnip greens).
• Tofu (set with calcium).
• Small fish with bones (including sardines and canned salmon).

Some foods and drinks are fortified with calcium. A food is fortified when the manufacturer adds vitamins or minerals that the food does not naturally have. Examples of foods fortified with calcium are certain brands of juice, soymilk, oatmeal, and breakfast cereal.

Some supplements contain calcium. Talk to your health care provider if you are thinking about taking a calcium supplement.

What does vitamin D do for our bones?

Vitamin D promotes bone health in these ways:

• Helps absorb the calcium we get from food.
• Along with calcium, helps protects older adults from osteoporosis.
• Promotes healthy functioning of our muscles and immune system. We need strong muscles to help us balance and reduce the risk of falling and breaking bones.

What happens to our bones without enough vitamin D?

When children do not get enough vitamin D, they can develop rickets. With rickets, the bones are soft, weak, deformed, and painful.

In adults, too little vitamin D over time can cause:

• Osteomalacia, a painful condition that makes bones and muscles weak and more likely to bend and break.
• Osteoporosis.

How much vitamin D do we need?

Table 2 lists how much vitamin D people need every day to keep their bones healthy.

Table 2

Source: National Institutes of Health Office of Dietary Supplements

In the United States, most people do not consume enough vitamin D to meet recommended intakes. Some vitamin D can be made in the body with sun exposure. Still, many people have low vitamin D status.

What foods have vitamin D?

Not many foods have vitamin D. Some kinds of fish can provide some of the vitamin D we need each day. Examples are:

• Trout.
• Salmon.
• Tuna.
• Mackerel.

Most of the vitamin D that Americans get from food comes from fortified foods. Most milk and some yogurts in the United States are fortified with vitamin D, but most other dairy products do not have added vitamin D.

Other foods that may be fortified (check the label to be sure) include:

• Ready-to-eat breakfast cereals.
• Orange juice.

Some supplements contain vitamin D. Talk to your health care provider if you are thinking about taking a vitamin D supplement.