An OB-GYN Answers All Your Questions About Prenatal Vitamins

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By Anna Gannon | Medically Reviewed by Dr. Sheryl A. Ross | Updated on Feb 7, 2024
Image for article An OB-GYN Answers All Your Questions About Prenatal Vitamins

TLDR: Prenatal vitamins are important to take whether you’re trying to conceive or are already pregnant. Here you’ll learn what vitamins and minerals to look for in a prenatal vitamin, whether the form matters (gummy vs. liquid vs. pill), and why you should keep it up even after you give birth. 


When I became pregnant with my daughter, I didn’t know which prenatal vitamin to choose. So, I did what so many other pregnant women do: I went in for my initial doctor’s visit and asked my ob-gyn to recommend one. Within seconds, they prescribed me a $60 bottle. I began taking it the next day. 

However, a few weeks later I began to recognize a strange connection between my morning sickness and my prenatal vitamins. Every day, I would wake up feeling fine, but then the moment I took my vitamin, I would feel nauseous. At first, I thought it was just a coincidence, but after experimenting with not taking the vitamin one morning, I found that my nausea completely stopped.

After reaching out to my doctor about this, they switched me to an over-the-counter $10 bottle of gummy prenatal vitamins, and to my surprise, my sickness never came back. I wondered why.

I talked with Dr. Sherry Ross, ob-gyn and author of She-ology: The Definitive Guide to Women’s Intimate Health1 , to find out everything you need to know when it comes to choosing the best prenatal vitamin for you.

Dr. Sherry Ross: Your calorie and nutrient requirements increase during pregnancy, and the average diet can leave gaps in your pregnancy's nutritional requirements. This means you are missing out on vital nutrients your body and growing baby need to function and develop properly. Taking a complete prenatal vitamin serves as an insurance policy, ensuring you are getting what is missing from your diet and satisfying the additional nutrient recommendations needed in pregnancy.

What Should You Look for When Choosing a Prenatal Vitamin?

SR: A prenatal vitamin is designed to meet the demanding daily nutrient requirements for a woman during this hypermetabolic time. Women who are pregnant need additional folate, iron, calcium, Vitamin A, B-complex, C, D, zinc, and omega-3 fish oil. 

These specific vitamins, minerals, and antioxidants are needed to help support the growth and development of a healthy baby. These key ingredients are needed specifically for spine, bone, brain, and red blood cell development.

Are There Differences Between Prenatal Vitamin Pills or Gummies? Over-the-counter or Prescription?

SR: Everyone wants to know if it’s better to take a soft gel, liquid, tablet, or chewable for the best absorption of the vitamins, minerals, and antioxidants in a prenatal vitamin. The form that your prenatal vitamin comes in has little effect on its absorption. In other words, liquid vitamins are not better absorbed than tablets. The absorption of your prenatal vitamin, regardless of its form, occurs in the stomach. 

You have to look at the ingredient list located on the prenatal vitamin to ensure you are getting exactly what is recommended. In a perfect world, you would take your prenatal vitamin in any format you prefer—separately from calcium and iron. Both of these minerals should be taken separately since they will affect the absorption of other nutrients. 

However, it is important to find a prenatal vitamin that has the U.S. Pharmacopeia symbol on the label. The USP symbol verifies that the vitamin has been tested showing it has all the nutrients represented on the supplemental facts panel once it dissolves, without containing high amounts of contaminants.

Are There Side Effects To Taking a Prenatal Vitamin?

SR: Since prenatal vitamins have more iron and higher doses of other vitamins and minerals, gastrointestinal side effects are common. Nausea, vomiting, diarrhea, and constipation are common side effects of prenatal vitamins.

When Should You Start Taking a Prenatal Vitamin?

SR: It’s best for women to start taking folate three months before conception. Making sure that your prenatal or multivitamin contains at least 400 mcg-1 mg of folate is [important]. Folate has been shown to reduce the incidence of spinal defects, aka neural tube defects. Another recent study showed women who took folate preconceptionally also had a reduced incidence of autism2 . Taking additional omega-3 fish oil helps the healthy development of the fetal brain and visual system. Additional vitamin D supplementation may also be needed if you are deficient.

How Long After Giving Birth Should You Take a Prenatal Vitamin?

SR: Many women think once they have had the baby, they don’t need to continue taking prenatal vitamins anymore. This is not the case. If you are breastfeeding, your body requires more vitamins and minerals than during your pregnancy. Continuing to take your prenatal vitamins, extra vitamin D, and omega-3 fish oil to help ensure your growing newborn gets those vital nutrients it needs.

Pregnancy can be a time of great excitement but also one filled with a lot of uncertainty, but hopefully, picking the best prenatal vitamin doesn’t have to be tough. As always, check in with your doctor if you have any questions or concerns about your nutrition or vitamin needs. 

About Our Expert

Sheryl A. Ross, M.D., “Dr. Sherry1 ,” is an ob-gyn, entrepreneur, author, and women’s health expert.  She was named one of the best doctors by The Hollywood Reporter, Southern California Super Doctor, Castle Connolly Exceptional Women, and Top Doctor in OB-GYN and given the Patients Choice Award. She is the author of the book, “She-ology: The Definitive Guide to Women’s Intimate Health. Period,which was named one of the 6 Most Life-Changing Wellness Books of 2017 by Prevention.com and Women’s Health Magazine.

Pregnant woman holding her stomach on a bed with a plant in the background

Want evidence-based health & wellness advice for fertility, pregnancy, and postpartum delivered to your inbox?

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  1. Sheryl A. Ross"She-ology: The Definitive Guide to Women's Intimate Health. Period."https://www.drsherry.com/products/she-ology-the-definitive-guide-to-womens-intimate-health-period.

  2. Hoxha, B., Hoxha, M., Domi, E., Gervasoni, J., Persichilli, S., Malaj, V., and Zappacosta, B"Folic Acid and Autism: A Systematic Review of the Current State of Knowledge"Cells, vol. 10, no. 8Aug 2, 2021, pp. 1976https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8394938/.


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Updated on Feb 7, 2024

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An OB-GYN Answers All Your Questions About Prenatal Vitamins

 Anna Gannon Profile Photo
By Anna Gannon | Medically Reviewed by Dr. Sheryl A. Ross | Updated on Feb 7, 2024
Image for article An OB-GYN Answers All Your Questions About Prenatal Vitamins

TLDR: Prenatal vitamins are important to take whether you’re trying to conceive or are already pregnant. Here you’ll learn what vitamins and minerals to look for in a prenatal vitamin, whether the form matters (gummy vs. liquid vs. pill), and why you should keep it up even after you give birth. 


When I became pregnant with my daughter, I didn’t know which prenatal vitamin to choose. So, I did what so many other pregnant women do: I went in for my initial doctor’s visit and asked my ob-gyn to recommend one. Within seconds, they prescribed me a $60 bottle. I began taking it the next day. 

However, a few weeks later I began to recognize a strange connection between my morning sickness and my prenatal vitamins. Every day, I would wake up feeling fine, but then the moment I took my vitamin, I would feel nauseous. At first, I thought it was just a coincidence, but after experimenting with not taking the vitamin one morning, I found that my nausea completely stopped.

After reaching out to my doctor about this, they switched me to an over-the-counter $10 bottle of gummy prenatal vitamins, and to my surprise, my sickness never came back. I wondered why.

I talked with Dr. Sherry Ross, ob-gyn and author of She-ology: The Definitive Guide to Women’s Intimate Health1 , to find out everything you need to know when it comes to choosing the best prenatal vitamin for you.

Dr. Sherry Ross: Your calorie and nutrient requirements increase during pregnancy, and the average diet can leave gaps in your pregnancy's nutritional requirements. This means you are missing out on vital nutrients your body and growing baby need to function and develop properly. Taking a complete prenatal vitamin serves as an insurance policy, ensuring you are getting what is missing from your diet and satisfying the additional nutrient recommendations needed in pregnancy.

What Should You Look for When Choosing a Prenatal Vitamin?

SR: A prenatal vitamin is designed to meet the demanding daily nutrient requirements for a woman during this hypermetabolic time. Women who are pregnant need additional folate, iron, calcium, Vitamin A, B-complex, C, D, zinc, and omega-3 fish oil. 

These specific vitamins, minerals, and antioxidants are needed to help support the growth and development of a healthy baby. These key ingredients are needed specifically for spine, bone, brain, and red blood cell development.

Are There Differences Between Prenatal Vitamin Pills or Gummies? Over-the-counter or Prescription?

SR: Everyone wants to know if it’s better to take a soft gel, liquid, tablet, or chewable for the best absorption of the vitamins, minerals, and antioxidants in a prenatal vitamin. The form that your prenatal vitamin comes in has little effect on its absorption. In other words, liquid vitamins are not better absorbed than tablets. The absorption of your prenatal vitamin, regardless of its form, occurs in the stomach. 

You have to look at the ingredient list located on the prenatal vitamin to ensure you are getting exactly what is recommended. In a perfect world, you would take your prenatal vitamin in any format you prefer—separately from calcium and iron. Both of these minerals should be taken separately since they will affect the absorption of other nutrients. 

However, it is important to find a prenatal vitamin that has the U.S. Pharmacopeia symbol on the label. The USP symbol verifies that the vitamin has been tested showing it has all the nutrients represented on the supplemental facts panel once it dissolves, without containing high amounts of contaminants.

Are There Side Effects To Taking a Prenatal Vitamin?

SR: Since prenatal vitamins have more iron and higher doses of other vitamins and minerals, gastrointestinal side effects are common. Nausea, vomiting, diarrhea, and constipation are common side effects of prenatal vitamins.

When Should You Start Taking a Prenatal Vitamin?

SR: It’s best for women to start taking folate three months before conception. Making sure that your prenatal or multivitamin contains at least 400 mcg-1 mg of folate is [important]. Folate has been shown to reduce the incidence of spinal defects, aka neural tube defects. Another recent study showed women who took folate preconceptionally also had a reduced incidence of autism2 . Taking additional omega-3 fish oil helps the healthy development of the fetal brain and visual system. Additional vitamin D supplementation may also be needed if you are deficient.

How Long After Giving Birth Should You Take a Prenatal Vitamin?

SR: Many women think once they have had the baby, they don’t need to continue taking prenatal vitamins anymore. This is not the case. If you are breastfeeding, your body requires more vitamins and minerals than during your pregnancy. Continuing to take your prenatal vitamins, extra vitamin D, and omega-3 fish oil to help ensure your growing newborn gets those vital nutrients it needs.

Pregnancy can be a time of great excitement but also one filled with a lot of uncertainty, but hopefully, picking the best prenatal vitamin doesn’t have to be tough. As always, check in with your doctor if you have any questions or concerns about your nutrition or vitamin needs. 

About Our Expert

Sheryl A. Ross, M.D., “Dr. Sherry1 ,” is an ob-gyn, entrepreneur, author, and women’s health expert.  She was named one of the best doctors by The Hollywood Reporter, Southern California Super Doctor, Castle Connolly Exceptional Women, and Top Doctor in OB-GYN and given the Patients Choice Award. She is the author of the book, “She-ology: The Definitive Guide to Women’s Intimate Health. Period,which was named one of the 6 Most Life-Changing Wellness Books of 2017 by Prevention.com and Women’s Health Magazine.

Pregnant woman holding her stomach on a bed with a plant in the background

Want evidence-based health & wellness advice for fertility, pregnancy, and postpartum delivered to your inbox?

Your privacy is important to us. By subscribing you agree to our Privacy Policy and Terms & Conditions.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Expectful uses only high-quality sources, including academic research institutions, medical associations, and subject matter experts.

  1. Sheryl A. Ross"She-ology: The Definitive Guide to Women's Intimate Health. Period."https://www.drsherry.com/products/she-ology-the-definitive-guide-to-womens-intimate-health-period.

  2. Hoxha, B., Hoxha, M., Domi, E., Gervasoni, J., Persichilli, S., Malaj, V., and Zappacosta, B"Folic Acid and Autism: A Systematic Review of the Current State of Knowledge"Cells, vol. 10, no. 8Aug 2, 2021, pp. 1976https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8394938/.


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