Calcium builds your baby’s bones and teeth. You need the same amount in pregnancy as before it, but most of it has to come from food, because prenatal vitamins usually contain only a fraction of what you need.

The short version

  • How much: 1,000 mg a day for women 19 to 50 and 1,300 mg a day for teens 14 to 18, the same as before pregnancy, according to the NIH.
  • Where it comes from: milk, yogurt, and cheese are the richest sources. Fortified plant milks and juices, tofu made with calcium sulfate, and canned fish with bones also count.
  • Prenatal vitamins: most contain about 200 mg, and gummies often contain none. They won’t close the gap on their own.
  • Supplements: not routine. ACOG recommends 1,500 to 2,000 mg a day only for women whose diet gives them less than 600 mg a day.
  • Upper limit: 2,500 mg a day for women 19 to 50 and 3,000 mg for teens, from food and supplements together.

Why calcium matters

Calcium is the main mineral in bones and teeth. Your baby needs it to build bones, and your body also uses it for muscles, nerves, blood clotting, and blood vessels. About 98% of your body’s calcium is stored in your bones, and your body draws on that store to keep your blood level steady, according to the NIH. Vitamin D is needed for your gut to absorb calcium.

Do women get enough?

Many do, with some help from supplements, but not all:

  • In national survey data from 2001 to 2014, about 1 in 5 pregnant women (21%) got less calcium from food than the average requirement. When supplements were counted, that fell to about 1 in 8 (13%).
  • Teens 14 to 18, women with less than a high school education, and women who aren’t non-Hispanic White were more likely to fall short.
  • Calcium is a “nutrient of public health concern” in the Dietary Guidelines for Americans because many people in the U.S. don’t get enough.

If you don’t eat dairy or calcium-fortified foods, you’re more likely to run low. That includes women who are lactose intolerant, have a milk allergy, or follow a vegan diet.

Where to get it

Food

Milk, yogurt, and cheese are the richest natural sources, and about 72% of the calcium in U.S. diets comes from dairy, according to the NIH. These amounts come from the NIH. Fortified products vary by brand, so check the label.

Food and serving Calcium (mg)
Yogurt, plain, low-fat, 8 ounces 415
Orange juice, calcium-fortified, 1 cup 349
Mozzarella, part-skim, 1.5 ounces 333
Sardines, canned in oil, with bones, 3 ounces 325
Cheddar cheese, 1.5 ounces 307
Milk, nonfat, 1 cup 299
Soy milk, calcium-fortified, 1 cup 299
Tofu, firm, made with calcium sulfate, ½ cup 253
Salmon, pink, canned, with bones, 3 ounces 181
Cottage cheese, 1% fat, 1 cup 138

Two ways to reach 1,000 mg

A day Calcium
With dairy: 1 cup milk, 8 ounces low-fat yogurt, 1.5 ounces cheddar About 1,020 mg
Without dairy: 1 cup fortified soy milk, 1 cup fortified orange juice, ½ cup calcium-set tofu, plus a prenatal with 200 mg About 1,100 mg

What your body absorbs

The calcium on a label isn’t all absorbed. The NIH notes:

  • You absorb about 30% of the calcium in dairy products and fortified foods.
  • Spinach has calcium, but only about 5% of it is absorbed, compared with 27% from milk. Compounds in spinach bind to the calcium.
  • Broccoli, kale, and cabbage are absorbed about as well as milk, but a serving has much less calcium.
  • Low vitamin D lowers absorption a lot, and caffeine and phosphorus lower it a little.

So greens help, but they’re a poor way to hit 1,000 mg on their own.

Prenatal vitamins

Prenatals don’t contain much calcium. In a 2021 review of 188 prenatal vitamins, 78% included calcium, with a median of 200 mg per serving. Another review found that over-the-counter prenatals averaged 368 mg and prescription ones 172 mg. Gummy prenatals often contain no calcium, according to the NIH. See Prenatal Vitamin Questions, Answered.

Do you need a calcium supplement?

Most women who eat dairy or calcium-fortified foods don’t. A supplement is mainly for women whose diet leaves them well short. The NIH summarizes what the main groups advise:

  • ACOG: 1,500 to 2,000 mg a day of supplemental calcium for pregnant women who take in less than 600 mg a day, to lower the risk of preeclampsia (a dangerous rise in blood pressure). Two cups of milk gives you about 600 mg.
  • World Health Organization: the same amount for women with low calcium intake, divided into three doses and taken with meals, and kept several hours apart from iron supplements.
  • Dietary Guidelines for Americans: no calcium supplement advice, but they flag calcium as underconsumed.

What the research shows

A 2024 review of 26 trials with about 20,000 women found that calcium supplements lowered the risk of preeclampsia by 49% and of gestational high blood pressure by 30%. They made no clear difference to preterm birth, low birth weight, or deaths. The benefit appears mainly in women who start out with low calcium intake, and many of the trials had weaknesses, which is why supplements are usually advised only for women with low intakes. Whether calcium prevents leg cramps in pregnancy is unclear.

If you take a supplement

  • Forms: the two main forms are calcium carbonate and calcium citrate. Calcium carbonate is absorbed best with food, according to the NIH.
  • Antacids count. Tums and Rolaids contain calcium carbonate, so add them to your total if you use them for heartburn.
  • Keep it apart from iron. Calcium can interfere with iron absorption, so take a calcium supplement at a different time of day from your prenatal or iron pill.
  • Medicines: calcium can interfere with some medicines, including dolutegravir (an HIV medicine) and lithium. Tell your provider and pharmacist what you take.
  • Upper limit: 2,500 mg a day for women 19 to 50 and 3,000 mg for teens, from food and supplements together. About 3% of pregnant women in national survey data from 2001 to 2014 went over it.

What to do now

  • Add up a typical day with the table above. Three to four servings of dairy or fortified foods, plus your prenatal, usually gets you to 1,000 mg.
  • Check your prenatal label for calcium. If it says gummy, it may have none.
  • If you eat little dairy or fortified food, ask your provider whether you need a supplement.
  • Keep any calcium supplement apart from your iron.
  • Keep your vitamin D up too, since it helps you absorb calcium. See Vitamin D in Pregnancy.

Related reading

Sources

Updated November 2026. This article is for general information and is not a substitute for advice from your health care provider.