Prenatal Vitamins—What You Need and What You Don’t

Emily Oster

9 min Read Emily Oster

Emily Oster

Prenatal Vitamins—What You Need and What You Don’t

Why you can skip the expensive pills

Emily Oster

9 min Read

Prenatal vitamins! If there is any product that seems designed to prey on our fears, it is this one. You’re newly pregnant, or trying to get pregnant. You want to do it right — yet there are so many things that feel complicated and new. Everyone agrees you need prenatal vitamins, so you get them. But do you want to be that person who just … buys the generic prenatal vitamins? You’re a sitting duck for ads that promise that some particular prenatal vitamins are going to give you the absolute best baby.  

And that best baby is going to cost you, or it might. On Amazon, prenatal vitamins range from 11 cents per pill (Nature Made) up to 83 cents (New Chapter, for women over 35). The question you face: is there any reason to pay eight times as much for one pill over another? 

Setting the stage: Vitamins

Before we get into prenatals, I want to very briefly address the overall issue of vitamins. For more on this, please visit this post, which is all about vitamins in general. The short summary is: In the vast majority of cases, people do not need vitamins. Unless you have a specific vitamin deficiency — which is extremely rare for people who have reliable food access — you do not benefit from more vitamins through supplementation.  

True vitamin deficiencies can be dangerous and even deadly. If you’re on a boat in the 16th century, eating only hardtack, you could get scurvy and die. But your need for (in this case) vitamin C to prevent scurvy is almost certainly met by what you’re eating. A few packets of ketchup a day would be enough to get all the vitamin C you need.  

What I’m saying is that vitamins are mostly pointless for people in general, and before you write back about this to indicate your disagreement, please read the original post

Prenatal vitamins

There are some components of prenatal vitamins that you do need, some that are questionable, and many that are a waste. Let’s review.

Items you definitely or very likely need

Folic acid  

The number one thing you should have in your prenatal vitamin is folic acid (or folate). Folic acid has been shown in randomized trials to reduce the risk of neural tube defects by between 70% and 95%. Neural tube defects (like spina bifida) are rare already, but supplementation pushes them close to zero. The recommended dose is at least 400 micrograms (mcg) per day; higher is also okay.

There is a lot of debate on the internet about folic acid versus folate. Folate is the nutrient you need, and it’s found in food. Folic acid is a less expensive synthetic form of folate that your body can break down into folate. Prenatal vitamins can also contain folate directly. For some people, a genetic variant may limit their ability to break down folic acid into folate. However, there isn’t any strong evidence to suggest that folate is better — this suggests that the vast majority of people are able to use folic acid to a sufficient degree. And the randomized trials all use folic acid. There isn’t anything wrong with folate, but it’s also unnecessary to pay more for it. 

Iron (+ vitamin C)

Anemia (low iron) is a common issue for women in general and pregnant and postpartum women in particular. Anemia can cause low energy, fatigue, depression, and dizziness. Most pregnant women should be screened for low iron and in extreme cases may need more than supplementation. But a very large share of women would benefit from an iron supplement during pregnancy. An easy way to get it is in your prenatal vitamin.

You also want vitamin C in your vitamin because it helps absorb iron. It’s otherwise useless (see below), but it matters here. 

(Yes, you can have too much iron, although it is not common. This is why a blood test is useful.)

Vitamin B12 if you do not eat animal products

Vitamin B12 is necessary if you do not eat animal products, as that’s the only place to get it otherwise. This is a supplement you’re likely taking regularly if you’re in this group, but it’s especially important in pregnancy.

Specific vitamin deficiencies

I want to call out: you might have a specific vitamin deficiency. It’s not that likely! But if you do, you should be taking a supplement, whether pregnant or not. If you eat a solely plant-based diet, there are a few other nutrients (iodine, zinc) that you’re more likely to be deficient in. Again, this is broader than pregnancy.

Items with mixed evidence, or theory but no evidence

DHA

DHA is an omega-3 fatty acid that is found in cold-water fish. It’s also possible to get it in supplement form through fish oil. There is a lot of speculation that DHA consumption during pregnancy could improve kids’ cognitive development.

The data is, at best, pretty mixed. There is, for example, a sizable randomized trial with follow-up at 18 months, 4 years, and 7 years that showed no impacts of DHA supplementation on cognitive test performance. Then we have a second randomized trial, which shows impacts on one cognitive test but not another at age 5. Overall, as a Cochrane review of trials points out, there is little evidence to support the value of DHA in development. (There is plenty of data showing that DHA consumption and child development is correlated, but that evidence is unlikely to be causal, due to differences across women.)

However: fish oil supplements do seem to reduce the risk of preterm birth in trials. We also see this reduction from fish consumption, and it seems to be larger for people who have low omega-3s to begin with. This is probably the best reason to consider a prenatal that includes DHA. 

Choline

Choline is a nutrient found in a variety of animal products, especially fatty ones (salmon, eggs, beef liver, etc.). It’s important for brain function, so there is the idea that it might also be important for fetal brain development. There is some animal model evidence that might support this. There are also a couple of (very small) randomized trials in humans that show impacts of supplementation on cognitive function in elementary  school.

I’m skeptical of these studies for some of the reasons discussed in this post on p-hacking. The studies are not really large enough to be powered to find the effects that they do, so this makes me worry about publication bias. In the end, it feels like a theoretical possibility that is probably not important in practice.

To the extent that there is value in choline supplementation, it would likely be greater if you currently consumed fewer animal products in your diet.

Vitamin D and calcium

There are theoretical reasons why calcium might be beneficial during pregnancy, mostly if you consume a diet with very low calcium. Similarly, vitamin D is broadly relevant for bone health, so it seems like it might be important. But we don’t have any concrete data suggesting there is some known threshold that matters.

Things with no evidence

A typical prenatal vitamin contains most or all of the above nutrients, plus a lot of other stuff. This includes (typically) vitamin A, vitamin E, vitamin K, thiamin, riboflavin, niacin, biotin, magnesium, and zinc. Sometimes there are others. 

There is no compelling evidence that these are necessary in pregnancy or otherwise, for nearly all people. It’s not that they are bad for you (at least not at the levels they are in the vitamins); it’s just that they are unnecessary. You definitely should not pay more for them. 

The ideal prenatal

Here’s what you want in your prenatal vitamin if you are a consumer of animal products:

  • Folic acid
  • Iron
  • Vitamin C
  • DHA (for the preterm birth benefits)

If you do not consume animal products, add B12, plus a few others depending on your diet.

That is it. Any prenatal vitamin that contains these is enough. And lest you be concerned that you need to buy an expensive prenatal because some vitamins are created differently, they aren’t. Vitamins are just vitamins. If they come in a fancy pill that looks like it’s full of gold (I’m looking at you, Ritual), it does not make them any different. 

You can find an inexpensive prenatal vitamin that contains the above. Actually, what’s hard is to find one that doesn’t have all the other things. Fortunately, it’s fine to have them even if they don’t matter. 

This list is good to keep in mind if you’re struggling with getting these pills down, especially during the first trimester. Folic acid is by far the most important. If you just took a single-ingredient folic acid pill, you would get a huge share of the most evidence-based benefits. 

So that’s it: prenatals are simple! Save money by buying something cheap. Trust me that there will be plenty of adorable onesies to spend it on later.

P.S. Before you ask, no, you do not need to take your prenatal after birth, even if you are breastfeeding. You might need iron, but the rest is a waste.

Bottom line

  • Vitamins are vitamins. Fancier vitamins are not better.
  • Folic acid is the most important prenatal ingredient. 
  • Iron (with vitamin C) and DHA are also nice to have. 
  • Other included ingredients have only weak or no evidence to support their use. 
A vitamin capsule opens to reveal fruits and vegetables on a blue background.

Aug 26 2022

4 min read

Should I Take Vitamins?

Ask ParentData

Emily Oster
Bowls of various pills and capsules on a light pink background.

Aug 08 2022

9 min read

Vitamins Are (Mostly) Pointless

Here are the few exceptions

Emily Oster
Prenatal vitamins scattered over images from a sonogram.

Mar 11 2022

3 min read

Should I Take Folate or Folic Acid in My Prenatal Vitamins?

My sister (who’s not a doctor) told me it’s better to take prenatal vitamins with folate instead of folic acid Read more

Emily Oster
Pregnant woman holds vitamins and a glass of water

Dec 12 2023

3 min read

Will Taking Prenatal Vitamin D Help Prevent Asthma in My Kids?

I would love to know Emily’s thoughts on the recent data around prenatal vitamin D reducing the risk of asthma. Read more

Emily Oster

Instagram

left right
If you have a fever during pregnancy, you should take Tylenol, both because it will make you feel better and because of concerns about fever in pregnancy (although these are also overstated).

The evidence that suggests risks to Tylenol focuses largely on more extensive exposure — say, taking it for more than 28 days during pregnancy. There is no credible evidence, even correlational, to suggest that taking it occasionally for a fever or headache would be an issue.

People take Tylenol for a reason. For many people, the choice may be between debilitating weekly migraines and regular Tylenol usage. The impacts studies suggest are very small. In making this decision, we should weigh the real, known benefit against the suggestion of this possible risk. Perhaps not everyone will come out at the same place on this, but it is crucial we give people the tools to make the choice for themselves.

#emilyoster #parentdata #tylenol #pregnancy #pregnancytips

If you have a fever during pregnancy, you should take Tylenol, both because it will make you feel better and because of concerns about fever in pregnancy (although these are also overstated).

The evidence that suggests risks to Tylenol focuses largely on more extensive exposure — say, taking it for more than 28 days during pregnancy. There is no credible evidence, even correlational, to suggest that taking it occasionally for a fever or headache would be an issue.

People take Tylenol for a reason. For many people, the choice may be between debilitating weekly migraines and regular Tylenol usage. The impacts studies suggest are very small. In making this decision, we should weigh the real, known benefit against the suggestion of this possible risk. Perhaps not everyone will come out at the same place on this, but it is crucial we give people the tools to make the choice for themselves.

#emilyoster #parentdata #tylenol #pregnancy #pregnancytips
...

Parenting trends are like Cabbage Patch Kids: they’re usually only popular because a bunch of people are using them! Most of the time, these trends are not based on new scientific research, and even if they are, that new research doesn’t reflect all of what we’ve studied before.

In the future, before hopping onto the latest trend, check the data first. Unlike Cabbage Patch Kids, parenting trends can add a lot of unnecessary stress and challenges to your plate. What’s a recent trend that you’ve been wondering about?

#parentdata #emilyoster #parentingtips #parentingadvice #parentinghacks

Parenting trends are like Cabbage Patch Kids: they’re usually only popular because a bunch of people are using them! Most of the time, these trends are not based on new scientific research, and even if they are, that new research doesn’t reflect all of what we’ve studied before.

In the future, before hopping onto the latest trend, check the data first. Unlike Cabbage Patch Kids, parenting trends can add a lot of unnecessary stress and challenges to your plate. What’s a recent trend that you’ve been wondering about?

#parentdata #emilyoster #parentingtips #parentingadvice #parentinghacks
...

As of this week, 1 million copies of my books have been sold. This feels humbling and, frankly, unbelievable. I’m so thankful to those of you who’ve read and passed along your recommendations of the books.

When I wrote Expecting Better, I had no plan for all of this — I wrote that book because I felt compelled to write it, because it was the book I wanted to read. As I’ve come out with more books, and now ParentData, I am closer to seeing what I hope we can all create. That is: a world where everyone has access to reliable data, based on causal evidence, to make informed, confident decisions that work for their families.

I’m so grateful you’re all here as a part of this, and I want to thank you! If you’ve been waiting for the right moment to sign up for full access to ParentData, this is it. ⭐️ Comment “Link” for a DM with a discount code for 20% off of a new monthly or annual subscription to ParentData! 

Thank you again for being the best community of readers and internet-friends on the planet. I am so lucky to have you all here.

#parentdata #emilyoster #expectingbetter #cribsheet #familyfirm #parentingcommunity

As of this week, 1 million copies of my books have been sold. This feels humbling and, frankly, unbelievable. I’m so thankful to those of you who’ve read and passed along your recommendations of the books.

When I wrote Expecting Better, I had no plan for all of this — I wrote that book because I felt compelled to write it, because it was the book I wanted to read. As I’ve come out with more books, and now ParentData, I am closer to seeing what I hope we can all create. That is: a world where everyone has access to reliable data, based on causal evidence, to make informed, confident decisions that work for their families.

I’m so grateful you’re all here as a part of this, and I want to thank you! If you’ve been waiting for the right moment to sign up for full access to ParentData, this is it. ⭐️ Comment “Link” for a DM with a discount code for 20% off of a new monthly or annual subscription to ParentData!

Thank you again for being the best community of readers and internet-friends on the planet. I am so lucky to have you all here.

#parentdata #emilyoster #expectingbetter #cribsheet #familyfirm #parentingcommunity
...

Just eat your Cheerios and move on.

Just eat your Cheerios and move on. ...

The AAP’s guidelines recommend sleeping in the same room as your baby “ideally for the first six months.” However, the risk of SIDS is dramatically lower after four months, and the evidence in favor of the protective effect of room sharing is quite weak (both overall and even more so after four months). There is also growing evidence that infants who sleep in their own room by four months sleep better at four months, better at nine months, and even better at 30 months.

With this in mind, it’s worth asking why this recommendation continues at all — or at least why the AAP doesn’t push it back to four months. They say decreased arousals from sleep are linked to SIDS, which could mean that babies sleeping in their own room is risky. But this link is extremely indirect, and they do not show direct evidence to support it.

According to the data we have, parents should sleep in the same room as a baby for as long as it works for them! Sharing a room with a child may have negative impacts on both child and adult sleep. We should give families more help in navigating these trade-offs and making the decisions that work best for them.

#emilyoster #parentdata #roomsharing #sids #parentingguide

The AAP’s guidelines recommend sleeping in the same room as your baby “ideally for the first six months.” However, the risk of SIDS is dramatically lower after four months, and the evidence in favor of the protective effect of room sharing is quite weak (both overall and even more so after four months). There is also growing evidence that infants who sleep in their own room by four months sleep better at four months, better at nine months, and even better at 30 months.

With this in mind, it’s worth asking why this recommendation continues at all — or at least why the AAP doesn’t push it back to four months. They say decreased arousals from sleep are linked to SIDS, which could mean that babies sleeping in their own room is risky. But this link is extremely indirect, and they do not show direct evidence to support it.

According to the data we have, parents should sleep in the same room as a baby for as long as it works for them! Sharing a room with a child may have negative impacts on both child and adult sleep. We should give families more help in navigating these trade-offs and making the decisions that work best for them.

#emilyoster #parentdata #roomsharing #sids #parentingguide
...

It was an absolute pleasure to be featured on the @tamronhallshow! We talked about all things data-driven parenting and, in this clip, what I call the plague of secret parenting. To balance having a career and having a family, we can’t hide the fact that we’re parents. If mothers and fathers at the top can speak more openly about child-care obligations, it will help us all set a new precedent.

Watch the full segment at the link in my bio 🔗

#tamronhall #tamronhallshow #emilyoster #parentingsupport #workingparents

It was an absolute pleasure to be featured on the @tamronhallshow! We talked about all things data-driven parenting and, in this clip, what I call the plague of secret parenting. To balance having a career and having a family, we can’t hide the fact that we’re parents. If mothers and fathers at the top can speak more openly about child-care obligations, it will help us all set a new precedent.

Watch the full segment at the link in my bio 🔗

#tamronhall #tamronhallshow #emilyoster #parentingsupport #workingparents
...

Invisible labor. It’s the work — in our households especially — that has to happen but that no one sees. It’s making the doctor’s appointment, ensuring birthday cards are purchased, remembering the milk.

My guest on this episode, @everodsky, has come up with a solution here, or at least a way for us to recognize the problem and make our own solutions. I’ve wanted to speak with Eve for ages, since I read her book Fair Play. We had a great conversation about the division of household labor, one I think you’ll get a lot out of!

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#emilyoster #parentdata #parentdatapodcast #parentingpodcast #householdtips #fairplay #invisiblelabor

Invisible labor. It’s the work — in our households especially — that has to happen but that no one sees. It’s making the doctor’s appointment, ensuring birthday cards are purchased, remembering the milk.

My guest on this episode, @everodsky, has come up with a solution here, or at least a way for us to recognize the problem and make our own solutions. I’ve wanted to speak with Eve for ages, since I read her book Fair Play. We had a great conversation about the division of household labor, one I think you’ll get a lot out of!

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#emilyoster #parentdata #parentdatapodcast #parentingpodcast #householdtips #fairplay #invisiblelabor
...

Prenatal vitamins 💊 If there is any product that seems designed to prey on our fears, it’s this one. You’re newly pregnant and you want to do it right. Everyone agrees you need prenatal vitamins, so you get them. But do you want to be that person who just… buys the generic prenatal vitamins?

Good news: fancier vitamins are not better.  Folic acid is the most important prenatal ingredient. Iron (with vitamin C) and DHA are also nice to have. Other included ingredients have only weak or no evidence to support their use. (If you do not consume animal products, add B12, plus a few others depending on your diet.)

Vitamins are just vitamins. Any prenatal vitamin that contains these is enough. 

Comment “Link” for a DM to an article with everything you need to know about prenatal vitamins.

#emilyoster #parentdata #prenatalvitamins #pregnancydiet #pregnancytips

Prenatal vitamins 💊 If there is any product that seems designed to prey on our fears, it’s this one. You’re newly pregnant and you want to do it right. Everyone agrees you need prenatal vitamins, so you get them. But do you want to be that person who just… buys the generic prenatal vitamins?

Good news: fancier vitamins are not better. Folic acid is the most important prenatal ingredient. Iron (with vitamin C) and DHA are also nice to have. Other included ingredients have only weak or no evidence to support their use. (If you do not consume animal products, add B12, plus a few others depending on your diet.)

Vitamins are just vitamins. Any prenatal vitamin that contains these is enough.

Comment “Link” for a DM to an article with everything you need to know about prenatal vitamins.

#emilyoster #parentdata #prenatalvitamins #pregnancydiet #pregnancytips
...

When it comes to introducing your newborn to the world, timing matters. It’s a good idea to minimize germ exposure in the first 6-8 weeks; after that, it’s inevitable and, very likely, a good idea! This doesn’t mean you need to be trapped inside. The most significant exposure risks are from seeing other people at home — family, etc. These interactions are not infinitely risky, but they do pose more risk than a walk or a trip to the grocery store, since they involve closer interaction. Think simple and make sure everyone is washing their hands before holding the baby. 💛

#parentdata #emilyoster #newborncare #parentingadvice #parentingtips

When it comes to introducing your newborn to the world, timing matters. It’s a good idea to minimize germ exposure in the first 6-8 weeks; after that, it’s inevitable and, very likely, a good idea! This doesn’t mean you need to be trapped inside. The most significant exposure risks are from seeing other people at home — family, etc. These interactions are not infinitely risky, but they do pose more risk than a walk or a trip to the grocery store, since they involve closer interaction. Think simple and make sure everyone is washing their hands before holding the baby. 💛

#parentdata #emilyoster #newborncare #parentingadvice #parentingtips
...

The first edition of Hot Flash is out now! Comment “Link” for a DM to learn more about the late-reproductive stage.

There are times when we expect hormonal shifts. Our reproductive lives are bookended by puberty and menopause. We discuss those changes often because they are definitive and dramatic — a first period is something many of us remember clearly. But between ages 13 and 53, our hormones are changing in more subtle ways. During the late-reproductive stage (in your 40s), you can expect a lot of changes in your menstrual cycle, including the length and symptoms you experience throughout. It’s an important time in our lives that is often overlooked!

🔥 Hot Flash from ParentData is a weekly newsletter on navigating your health and hormones in the post-reproductive years. Written by Dr. Gillian Goddard, Hot Flash provides all of the information you need to have a productive, evidence-based conversation about hormonal health with your doctor.

#emilyoster #parentdata #hotflash #perimenopause #womenshealth

The first edition of Hot Flash is out now! Comment “Link” for a DM to learn more about the late-reproductive stage.

There are times when we expect hormonal shifts. Our reproductive lives are bookended by puberty and menopause. We discuss those changes often because they are definitive and dramatic — a first period is something many of us remember clearly. But between ages 13 and 53, our hormones are changing in more subtle ways. During the late-reproductive stage (in your 40s), you can expect a lot of changes in your menstrual cycle, including the length and symptoms you experience throughout. It’s an important time in our lives that is often overlooked!

🔥 Hot Flash from ParentData is a weekly newsletter on navigating your health and hormones in the post-reproductive years. Written by Dr. Gillian Goddard, Hot Flash provides all of the information you need to have a productive, evidence-based conversation about hormonal health with your doctor.

#emilyoster #parentdata #hotflash #perimenopause #womenshealth
...

There are plenty of reels telling you how to parent. Plenty of panic headlines saying that “studies show” what’s best for your kid. Even good data, from a trusted source, can send us into a spiral of comparison. But I want you to remember that no one knows your kid better than you. It’s important to absorb the research, but only you will know the approach that works best for you and your child. 💙

Now tell me in the comments: what’s a parenting move you’ve made recently that feels right to you?

#parentingcommunity #parentingsupport #parentingquotes #emilyoster #parentdata

There are plenty of reels telling you how to parent. Plenty of panic headlines saying that “studies show” what’s best for your kid. Even good data, from a trusted source, can send us into a spiral of comparison. But I want you to remember that no one knows your kid better than you. It’s important to absorb the research, but only you will know the approach that works best for you and your child. 💙

Now tell me in the comments: what’s a parenting move you’ve made recently that feels right to you?

#parentingcommunity #parentingsupport #parentingquotes #emilyoster #parentdata
...

Let’s talk about sex (after) baby! Today on the podcast, I was lucky enough to speak with @enagoski about her new book on sexual connection in long-term relationships. Especially after having kids, this is something many people struggle with. Emily tells us to stop worrying about what’s “normal” and focus on pleasure in its many forms.

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#parentdata #parentdatapodcast #emilyoster #emilynagoski #comeasyouare #cometogether #longtermrelationship #intimacy #relationships

Let’s talk about sex (after) baby! Today on the podcast, I was lucky enough to speak with @enagoski about her new book on sexual connection in long-term relationships. Especially after having kids, this is something many people struggle with. Emily tells us to stop worrying about what’s “normal” and focus on pleasure in its many forms.

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#parentdata #parentdatapodcast #emilyoster #emilynagoski #comeasyouare #cometogether #longtermrelationship #intimacy #relationships
...

Ever wondered if you can safely use leftover baby formula? 🍼 The CDC says to throw out unused formula immediately because of the risk of bacterial growth. However, research suggests that bacterial concentrations do not appreciably increase after 3, 12, or even 24 hours at refrigerator temperatures. Good news! This means there’s not a strong data-based reason to throw out formula right away if you store it in the fridge.

Comment “Link” for a DM to an article on another common formula question: should you throw away old formula powder?

#emilyoster #parentdata #babyformula #babyfeeding #parentingstruggles

Ever wondered if you can safely use leftover baby formula? 🍼 The CDC says to throw out unused formula immediately because of the risk of bacterial growth. However, research suggests that bacterial concentrations do not appreciably increase after 3, 12, or even 24 hours at refrigerator temperatures. Good news! This means there’s not a strong data-based reason to throw out formula right away if you store it in the fridge.

Comment “Link” for a DM to an article on another common formula question: should you throw away old formula powder?

#emilyoster #parentdata #babyformula #babyfeeding #parentingstruggles
...

What’s the most important piece of advice for new parents? Here’s one answer, but I want to hear from you! Share your suggestions in the comments ⬇️

#emilyoster #parentdata #parentingtips #parentingadvice #newparents #parentingcommunity

What’s the most important piece of advice for new parents? Here’s one answer, but I want to hear from you! Share your suggestions in the comments ⬇️

#emilyoster #parentdata #parentingtips #parentingadvice #newparents #parentingcommunity
...

What's in the bag of a Vagina Economist? 👀 Someone please tell me this looks familiar to you.

What`s in the bag of a Vagina Economist? 👀 Someone please tell me this looks familiar to you. ...