By: Rachel Neifeld RD, CDE, CDN

It’s known that eating well during pregnancy holds an abundance of health benefits for both mother and baby, but a new study has shed light on the extent to which nutrition during pregnancy can specifically affect a baby’s bone health.

A large study published in the American Journal of Clinical Nutrition found that children of mothers with higher intakes of protein, calcium, phosphorus, and vitamin B12 during pregnancy had higher bone mass at six years of age than children of mothers who had lower intakes of these nutrients. Higher intake of carbohydrate as well as higher homocysteine levels—an amino acid that builds up in the blood when B vitamins intake is low—were associated with lower childhood bone mass.

Not only can these important nutrients affect children’s’ bone development, but they are needed in adequate amounts during pregnancy to promote vital growth and development within the womb, including the repair of tissues and cells, normal heart function, and spinal cord and brain development. This research provides women with yet another reason to make those extra 300 calories needed during pregnancy count.

Along with taking a prenatal vitamin, pregnant women should strive to swap high carbohydrate, low nutrient-value foods for more nutrient-dense, “power” foods. Instead of choosing snacks with few vitamins and minerals such as chips, soda, and cookies, look for foods that provide more nutrients such as dried or fresh fruit, yogurt, nuts, and reduced-fat cheese with whole grain crackers.

Every meal, beverage, and snack can be a source of essential nutrients for a growing baby and is an opportunity for moms-to-be to make a healthy choice for their child; proper nutrition is necessary not only within the womb, but as growing research suggests, for the rest of their lives.

Below are the recommended amounts and sources of the nutrients found to promote children’s bone health:

Protein:  71 grams (may be a little more or less based on individual needs and activity levels).

  • You can get the recommended amount of protein by consuming about 5 ½ ounces of protein during the first trimester and 6 ½ during the second trimester. 1 ounce of meat, poultry or fish, ¼ cup cooked beans, 1 egg, 1 tablespoon of peanut butter, or ½ ounce of nuts or seeds can be considered as 1 ounce equivalent from the protein foods group.

Here’s what about 6 oz of protein servings looks like:

  • One egg (1 oz equivalent)
  • One 3-ounce serving of chicken breast (3-ounce equivalents)
  • ¼  cup cooked beans (1 ounce equivalent)
  • ½ ounce nuts which equals 12 almonds, 24 pistachios, or 7 walnut halves (each 1 -ounce equivalents)

Lean meats such as beef, poultry and fish contain the most protein. Dairy products such as low fat milk, cheese and eggs also contain good amounts of protein that our bodies can easily use. Beans, legumes and tofu are iron-rich, non-animal sources of protein for vegetarians and vegans. To increase the absorption of the iron from these sources of protein, it is recommended to consume them along with a vitamin C-rich food such as citrus fruits or tomatoes.

Calcium: 1000 milligrams daily (1300 milligrams for those younger than 19).

  • Milk and dairy products (preferably low fat) are the best source of calcium and also protein, phosphorus, and vitamins. You can also find it in fortified orange juice, sardines, and salmon with bones.
  • For vegans and those who are lactose intolerant, calcium can be found in plant sources such as collard greens, kale, mustard greens, spinach, and turnip greens. You can also try calcium-enriched tofu, soy milk, and rice milk.
  • If you eat dairy products, strive for 3 daily to get the recommended amount of calcium. One cup of milk, two small slices of Swiss cheese, or 1/3 cup of shredded cheese count as one cup. Two cups of calcium-rich vegetables count as 1 cup.
  • If you are lactose intolerant you could try lactase pills or drops to help break down the milk sugar. You could also take a daily antacid with calcium to boost your intake or purchase low-lactose milk and cheese. Also remember not to take calcium with iron as they interfere with each other’s absorption. Most prenatal vitamins do not contain enough calcium, so it is recommended you take a separate calcium supplement. Since only 500 mg can be absorbed at one time, you may want to take another 500 or 600 mg supplement at a different time of the day. Calcium citrate is better absorbed than calcium carbonate because it doesn’t require stomach acid to be broken down. If you take calcium carbonate, be sure to take it with a meal so it can break down more easily.

Vitamin B12: 2.6 milligrams

  • Aside from possibly affecting a child’s long-term bone health, vitamin B12 is needed in higher amounts before and in the beginning of pregnancy to ensure adequate development of the baby’s nervous system. Vitamin B12 is found mostly in meat and dairy foods- so as long as a woman includes lean protein and fish in her diet, she is likely obtaining enough.
  • For women who do not eat meat and especially for vegans who exclude dairy products from their diets, consuming fortified bread and breakfast cereals and possibly taking an additional vitamin B12 supplement is recommended.

Phosphorus: 700 milligrams

  • Dairy, nuts, beans, and meat are good sources of phosphorus. Women can obtain enough of this nutrient simply by consuming the recommended three daily servings of low fat dairy. Aside from dairy, great sources of phosphorus include heart healthy foods such as pinto beans, lentils, almonds, salmon, and halibut.


Source: Denise HM Heppe, Carolina Medina-Gomez, Albert Hofman, Oscar H Franco, Fernando Rivadeneira, and Vincent WV Jaddoe. Maternal first-trimester diet and childhood bone mass: the Generation R Study. Am J Clin Nutr 2013 ajcn.051052; First published online May 29, 2013. doi:10.3945/ajcn.112.051052