Vitamin D helps your body absorb calcium, the mineral your baby needs to build bones. Your need for it doesn’t change during pregnancy, but it can be hard to get enough from food alone, and the research on taking extra is still unsettled.

The short version

  • How much: 600 IU (15 micrograms) a day during pregnancy and breastfeeding, the same as before pregnancy, according to MedlinePlus.
  • Upper limit: 4,000 IU (100 micrograms) a day from all sources, unless your provider recommends more.
  • Where it comes from: sunlight on your skin, fatty fish, and fortified foods like milk and cereal. Most U.S. milk has about 100 IU per cup.
  • Prenatal vitamins: many include vitamin D, but amounts vary. Check the label.
  • Extra vitamin D: a 2024 review of the research found the evidence on whether extra vitamin D prevents pregnancy problems is uncertain. Getting the recommended amount is what’s well supported.

What vitamin D does

Vitamin D helps your body absorb calcium, which you and your baby need for normal bone formation, according to MedlinePlus. Without enough vitamin D, your body can’t absorb enough calcium, and bones can suffer. Over time, a lack of vitamin D can lead to weak bones in adults and a bone disease called rickets in children.

What the research shows about pregnancy

Low vitamin D in pregnancy has been linked in some studies to problems like preeclampsia (a dangerous rise in blood pressure), gestational diabetes, and low birth weight. The question is whether taking extra vitamin D prevents them.

The most recent Cochrane review, updated in 2024, looked at the clinical trials and found:

Outcome What the review found
Preeclampsia Evidence very uncertain
Gestational diabetes Evidence very uncertain
Preterm birth Evidence very uncertain
Low birth weight May be reduced (low-certainty evidence)
Severe bleeding after birth May be reduced, based on one study (low-certainty evidence)

Source: Cochrane, 2024.

An earlier Cochrane review on dose found that taking more than 600 IU a day may lower the risk of gestational diabetes, but that going to 4,000 IU or more made little or no difference compared with lower doses, according to Cochrane.

ACOG’s 2011 committee opinion on vitamin D took a similar position: women who aren’t at higher risk for low vitamin D generally get enough from a prenatal vitamin, and recommendations for extra vitamin D beyond that should wait for better evidence. So for now, aim for the recommended 600 IU, and talk with your provider before taking more.

How much you need

These amounts come from MedlinePlus, based on the National Academies’ recommendations.

Stage Daily need Upper limit
Teens and adults, including pregnancy and breastfeeding 600 IU (15 mcg) 4,000 IU (100 mcg)
Babies, birth to 6 months 400 IU (10 mcg) 1,000 IU (25 mcg)
Babies, 7 to 12 months 400 IU (10 mcg) 1,500 IU (38 mcg)

IU or mcg? Labels may list vitamin D in international units (IU), micrograms (mcg), or both. One microgram equals 40 IU, so 15 mcg is the same as 600 IU.

Check your prenatal vitamin. Many prenatals include vitamin D, but the amount varies from product to product. Add it to what you get from food and any other supplement, and keep the total under 4,000 IU unless your provider recommends otherwise.

Why the upper limit matters. Too much vitamin D makes your body absorb too much calcium. High blood calcium can cause nausea, vomiting, constipation, weakness, confusion, and kidney stones, and over time can damage the kidneys. Vitamin D toxicity almost always comes from taking too many supplements, not from food or sunlight.

Where to get it

Sunlight. Your skin makes vitamin D when it’s exposed to the sun, and most people get at least some of their vitamin D this way, according to MedlinePlus. How much you make varies a lot: cloudy days, shade, living farther north, and darker skin all cut down on it. Because sun exposure raises the risk of skin cancer, more than a few minutes without sunscreen isn’t recommended, so sunlight can’t be counted on to cover your needs.

Food. Very few foods have much vitamin D naturally, which is why many are fortified:

  • Fatty fish such as salmon, tuna, and mackerel are among the best natural sources. In pregnancy, choose lower-mercury options like salmon, and limit white (albacore) tuna to 1 serving (4 ounces) a week, as the FDA advises.
  • Fortified milk. Most U.S. milk has 400 IU per quart, or about 100 IU per cup. Cheese and ice cream usually aren’t fortified.
  • Other fortified foods include many breakfast cereals and some orange juice, yogurt, soy drinks, and margarine. Check the Nutrition Facts label.
  • Mushrooms have some vitamin D, and those treated with ultraviolet light have more.
  • Egg yolks, cheese, and beef liver have small amounts. (Limit liver in pregnancy because of its vitamin A content.)

Supplements. It can be hard to get enough from food alone, so many people rely on a prenatal vitamin or a separate supplement. Supplements come in two forms, D2 and D3. See Vitamin D Supplements in Pregnancy.

What to do now

  • Check how much vitamin D is in your prenatal vitamin.
  • Add vitamin D foods you eat regularly, like fortified milk, cereal, or salmon.
  • If you rarely get sun, have darker skin, or eat few fortified foods, ask your provider whether you’re getting enough. See Vitamin D Deficiency in Pregnancy.
  • Don’t go over 4,000 IU a day unless your provider tells you to.

Related reading

Sources

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