Taking prenatal vitamins when planning for pregnancy or early into your pregnancy can help you receive vital nutrients needed for fetal development.

There are a lot of limits on the types of medications and supplements you can take during pregnancy — but prenatal vitamins are not only allowed, they’re strongly recommended.

A good prenatal vitamin can help keep you and your growing baby healthy by ensuring that you’re both getting all the nutrients you need to make it through those 9 codependent months of pregnancy.

There are two answers here, but neither involves waiting until your first-trimester ultrasound.

When you decide to try for a pregnancy

Prenatal vitamins are an important part of preconception care.

In addition to scheduling a visit with your gynecologist, you should consider taking prenatal vitamins.

If you’re planning to start a family, it can be difficult to predict how long it will take you to get pregnant — it could be weeks or months.

As soon as you find out you’re pregnant

If you aren’t already taking prenatal vitamins, you should consider taking them once you receive a positive pregnancy test. Drugstores and grocery stores will have prenatal vitamins that you can purchase over the counter.

Speaking with your healthcare professional regarding your chosen vitamins can also be helpful. Your OB-GYN may eventually suggest a specific brand or even offer you a prescription.

Your body goes through many changes during pregnancy. As your baby grows, they rely on your body’s natural resources to develop vital organs. This may cause you to experience:

Your baby gets all the nutrients it needs directly from you, so it’s easy to become deficient in important vitamins and minerals during pregnancy. Beginning to take prenatal vitamins prior to pregnancy may make it easier to ensure your body has what it needs to nourish both of you.

Think of it like building up a reserve: If you have more than enough of the vitamins and nutrients you need to thrive, then you can afford to share them with your baby as they grow.

While having a well-rounded balance of vitamins and nutrients during pregnancy is important, some are truly MVPs. They can help your baby form vital organs and body systems, many of which begin developing in the earliest weeks of pregnancy.

According to the American College of Obstetricians and Gynecologists (ACOG), these are the most important nutrients you need:

Folic acid

One of the most important prenatal nutrients, this B vitamin is responsible for creating your baby’s neural tube, or the structure that eventually forms the brain and spinal column. Without a fully developed neural tube, a baby could be born with spina bifida or anencephaly.

According to the US Preventive Services Task Force (USPSTF), folic acid supplements significantly increase the likelihood of healthy neural tube growth. The American Academy of Pediatrics has also long held the position that folic acid can reduce neural tube defects by at least 50%.

The neural tube closes within the first 4 weeks after conception, so taking prenatal vitamins before pregnancy can be beneficial.

Because folic acid is so effective, the Centers for Disease Control and Prevention recommends that you take 400 micrograms (mcg) of folic acid daily, either as a prenatal vitamin or an individual supplement.

Iron

Iron supplies the fetus with blood and oxygen, helps build the placenta, and gives you the extra blood volume you need throughout pregnancy. Since pregnant people are prone to anemia, iron supplementation also ensures that you have the right amount of red blood cells in your blood.

Anemia during pregnancy is associated with higher rates of premature delivery and low infant birth weight.

Calcium

Your baby spends a lot of time in your uterus building up their bones and teeth. To achieve this Herculean feat, they need plenty of calcium — which means you need plenty of calcium, too.

If you don’t get enough calcium, your body will take calcium from your bones to supply your baby with what it needs during pregnancy. This can lead to temporary bone loss.

Generally speaking, the vitamins and nutrients included in prenatals won’t cause detrimental side effects.

That said, prenatal vitamins do contain nutrients specific to supporting pregnancy. If you aren’t pregnant, they may not be the best long-term choice.

Your iron needs, for example, increase from 18 milligrams to 27 milligrams during pregnancy. While the short-term side effects of too much iron include mild gastrointestinal (GI) upsets like constipation and nausea, over time that excess of nutrients could become more problematic.

Some celebrities swear by prenatal vitamins as the secret to their glowing skin and luscious locks because they contain biotin, one of the all-important B vitamins.

However, one study after another has failed to prove any significant beauty benefits to taking biotin.

Besides biotin, though, there aresome extra benefits to prenatal vitamins. If you take one with DHA, for example, you’ll get a boost of omega-3 fatty acids that may help your baby’s brain and eyes develop.

You may also get thyroid-regulating iodine, which can aid in your baby’s nervous system development.

Finally, there’s some research indicating that taking prenatal vitamins may increase your chances of pregnancy.

To be clear, prenatals are not a magic cure for fertility challenges and getting pregnant isn’t as simple as popping a vitamin. However, many nutrients in prenatal vitamins regulate the body systems responsible for making pregnancy possible.

There are dozens of options out there, but make sure you check for a few key things before buying a prenatal vitamin:

Regulatory oversight

This is a fancy way of reminding you to ensure that some certified organization has verified the health and ingredient claims made by your vitamin manufacturer.

Since the Food and Drug Administration doesn’t regulate anydietary supplements, including prenatal vitamins, look for a thumbs-up from groups like the Office of Dietary Supplements or the U.S. Pharmacopeia Convention.

Doses

Compare the amounts of key nutrients, like iron and folate, in your vitamin to ACOG’s recommended amounts. You don’t want to take a vitamin with too much or too little of what you need.

Over-the-counter (OTC) or prescription

Some insurance providers will cover some or all of the costs of prenatal vitamins, saving you money. If yours does, you may want to ask your provider for a prescription instead of buying your own.

If you still have questions about choosing the right vitamin, feel free to ask your doctor for advice. You can also visit our resource page to learn about some of the best prenatal vitamins to consider, too.

  • Ask your doctor about switching to another brand: Sometimes, a prenatal is formulated in a way that just doesn’t isn’t right for you.
  • Try a different method: Prenatals are often available as capsules, beverages, gummies, and even protein shakes — and ingesting them differently can aid the digestive process. Try switching from one large capsule to three gummies per day or splitting up two doses 12 hours apart.
  • Drink lots of water before and after: If you’re having constipation, make sure you keep your GI system flushed out. You can also add a fiber supplement if you’re really feeling backed up (but get a recommendation from your doctor first).
  • Experiment with food: If your vitamins make you nauseated, try taking them with or without food. Some people think taking vitamins on an empty stomach is irritating; others find that they can onlytake them on an empty stomach.

If you’re considering becoming pregnant in the next few months, starting a prenatal vitamin can help you and your baby grow strong and healthy.

If you’re not considering pregnancy at the moment but technically could become pregnant, stick to a daily folic acid supplement. It will give you what you need should you become pregnant without loading you up with an unnecessary excess of prenatal nutrients.