Vitamin D is an often overlooked nutrient you should be getting enough of during pregnancy to support your health as well as your baby’s development.

During pregnancy, it’s important that you obtain adequate nutrients to support fetal development, with folate, magnesium, and iron among the many nutrients you might need more of during this phase.

However, it’s also vital that you get enough amounts of other vitamins and minerals, too, such as vitamin D (calciferol). It’s common to need vitamin D supplements during pregnancy, but it’s important to discuss these with a doctor before taking them.

Vitamin D is a fat-soluble nutrient that is essential for numerous roles in the human body. Among these include:

  • bone health
  • boosted immune function
  • cellular growth
  • everyday neuromuscular functions
  • glucose metabolism
  • reduced inflammation

The National Institutes of Health Office of Dietary Supplements says that the recommended daily allowance (RDA) of vitamin D is 15 micrograms (mcg).

However, despite the fact that the RDA for pregnant and non-pregnant people is the same for vitamin D, it’s thought that 90% of people in the U.S. do not meet the estimated average requirement.

Not only is vitamin D an essential nutrient, but it can also support bone development in a fetus during pregnancy. Some research also points to a link between vitamin D intake and the reduced risk of:

Deciding whether you need vitamin D supplements during pregnancy ultimately depends on whether you have a deficiency. Research suggests that most people do need supplementation.

Vitamin D is naturally occurring in many food sources. These include:

  • fatty fish
  • egg yolks
  • fortified products such as plant-based or cow’s milk

However, if you don’t eat enough vitamin D-containing foods, you could be deficient in this important nutrient.

You also get some forms of vitamin D naturally through sun exposure. For this reason, some people who have very limited exposure to natural sunlight might also be vitamin D deficient.

A doctor may be able to determine if you have a vitamin D deficiency based on your diet, blood testing, and any related signs and symptoms. If vitamin D levels cannot be addressed through diet, they might then recommend supplements.

With that said, you should only take vitamin D as recommended by a doctor so that you do not experience toxicity from taking too much. There are also key benefits and risks to consider with vitamin D supplements during pregnancy.

Benefits

Vitamin D supplements can help correct a related nutritional deficiency during pregnancy and support your growing baby. In such cases, a daily dose of between 1,000 and 2,000 (25 to 50 mcg) international units (IUs) is considered safe.

A doctor will likely recommend supplements containing D3. Most prenatal vitamins sold in the U.S. also contain vitamin D, but many of these contain just 400 IUs.

A healthcare professional might also recommend vitamin D supplements during pregnancy if you have certain risk factors for a deficiency. These include:

Due to the important role of vitamin D in fetal development, one 2020 review recommends that all pregnant people receive supplementation to make sure they get enough of this nutrient. However, it’s important to ask a doctor before taking any new supplements.

Risks

The biggest risk of taking vitamin D supplements during pregnancy is toxicity. While rare, taking too much vitamin D is still a possibility you should discuss with your doctor.

The Office of Dietary Supplements also reports that the upper limit of vitamin D during pregnancy is 100 mcg. In other words, this is the highest amount that may be considered safe without causing side effects.

With that said, if you are already getting enough vitamin D, exceeding 100 mcg per day with supplementation could cause side effects.

This is why it’s important to work with a doctor to determine whether you need a vitamin D supplement. They can also check your vitamin D levels in your blood through a serum 25(OH)D test on a regular basis to see if you’re getting the right amount.

Also, you should never take regular multivitamins during pregnancy. These may contain certain nutrients at excess levels, such as vitamin A, that can be harmful to your baby.

Most cases of vitamin D deficiency are asymptomatic until levels are dangerously low. Talk with a doctor if you’re experiencing possible symptoms of vitamin D deficiency, such as:

  • bone pain
  • joint pain
  • muscle aches and weakness
  • twitching muscles
  • fatigue

While less common, signs and symptoms of vitamin D toxicity from taking too many supplements include:

  • nausea
  • vomiting
  • constipation
  • weakness
  • loss of appetite
  • unintentional weight loss

If you have concerns about possible vitamin D deficiency, talk with a doctor or your obstetrician right away. They can order blood tests to determine if you’re getting enough of this important nutrient and recommend possible supplementation when appropriate.

While the majority of females do not require vitamin D testing, a doctor will likely want to check your levels when you’re pregnant due to side effects on fetal development associated with low vitamin D. This is especially the case if you have risk factors for vitamin D deficiency.

You should also contact a doctor if you’re currently taking a prenatal vitamin and/or vitamin D supplements and have any other concerns about your levels.

Consider the following frequently asked questions about vitamin D during pregnancy, you might wish to discuss further at your next doctor’s appointment:

It’s important that you get enough vitamin D, but especially when you’re pregnant.

A doctor may recommend a prenatal multivitamin that has vitamin D as a key ingredient. If you are extremely deficient in vitamin D, they might also suggest additional supplementation. You should not, however, take a vitamin D supplement unless recommended by your doctor.

The recommended daily allowance for vitamin D during pregnancy is 15 mcg, and the upper limit is 100 mcg. A doctor can help you decide the exact amount you should take every day based on blood testing.

Research supports vitamin D and vitamin K as two important supplements during pregnancy, with the latter playing a role in blood clotting.

Unlike vitamin D, which may be taken up by a fetus, though, vitamin K cannot pass to your baby via the placenta as easily. This is why your newborn will usually be given a vitamin K shot within 6 hours after birth.

Most people do not get enough vitamin D, an important fat-soluble nutrient that helps with bone and immune health, among other functions.

Not getting enough vitamin D during pregnancy, however, may possibly increase the risk of inadequate bone development in babies and other possible side effects. As such, a doctor may recommend you increase your vitamin D intake with the help of supplementation.

It’s important to talk with a doctor before taking any new supplements, especially during pregnancy. They can recommend the right brand and dosage, and also help monitor your vitamin D levels.