Should you take prenatal vitamins before you get pregnant? Follow this guide to learn about the importance of prenatal vitamins and why you should take them when trying to conceive.

By: Libby Pellegrini MMS, PA-C

Medically Reviewed By: Cara Everett, MS, RDN, LDN

Publication Date: January 4th, 2024

Estimated Reading Time: 6 minutes

When you’re planning to get pregnant, it’s important to prepare your body for this major life change. Part of that process is taking a prenatal vitamin that meets your individual needs.

Prospective mothers are faced with many choices that can impact their health and that of their baby, including the right way to take prenatal vitamins before pregnancy. If you’re seeking answers to questions such as “How long does it take prenatal vitamins to work?” and “How long should I take a prenatal supplement before getting pregnant?” follow this guide for everything you need to know. 

Yes. Prenatal vitamins and the ideal first trimester diet not only help support the beginning of your pregnancy, but the right prenatal vitamin is also essential before you get pregnant. This is because prenatal vitamins help prepare your body for pregnancy ahead of time. 

Taking a prenatal vitamin when you’re trying to conceive also ensures that you’re supporting your baby’s development in the earliest days before you see a positive pregnancy test. 

One of the best examples of this relates to neural tube and brain development. 

The neural tube is the foundation of your baby’s brain and spinal cord, and it’s one of the first parts of the body to form. By the fourth week of pregnancy, the neural tube is closing so that the brain and spinal cord can begin developing. (1) 

Some women don’t even know they’re pregnant by the fourth week, and one-carbon nutrients such as folate and choline are critical for neural tube development during this time. (2) Deficiencies in essential nutrients like folate and choline have been linked to neural tube defects. (3) But by taking a comprehensive prenatal vitamin when you’re planning to conceive, you’ll be helping your baby’s health off to a good start.

When you start taking a prenatal vitamin, it can take some time for nutrient stores to build up in your body. This is especially true if you're deficient in any given nutrient.

For example, iron deficiency is common in women. (4) Iron needs increase in pregnancy to support your expanded blood volume and the baby’s iron needs. (5) For this reason, starting a prenatal vitamin with iron before pregnancy is a great way to make sure you’re optimizing your iron supply.

Health experts at the Mayo Clinic recommend beginning a prenatal vitamin at least three months before pregnancy. They also say it’s a smart idea for all women of childbearing age to take a daily prenatal supplement. (6)

Prenatal vitamins may take anywhere from one month to three months to be most effective in terms of establishing nutrient stores, especially folic acid. The American College of Obstetricians and Gynecologists (ACOG) advises women to begin taking a prenatal vitamin containing 400 mcg of folic acid at least one month before pregnancy. If you’re at higher risk of neural tube defects, talk to your healthcare provider about starting a high dose of folic acid three months before trying to conceive. (7)

According to ACOG, taking a prenatal vitamin before the start of pregnancy can also help reduce symptoms of nausea and vomiting that often occur in the first trimester. Prenatal vitamins are also associated with a lower risk of miscarriage.

Follow one simple rule when deciding on your prenatal vitamin regimen: Create a plan that’s easy to follow and stick with. 

It's not necessary to take prenatal vitamins if you aren't trying to get pregnant unless you've been advised to do so by your healthcare provider. Prenatal vitamins can support overall health with essential nutrients like folate, calcium, and vitamin D. But some prenatals include elevated amounts of vitamins and minerals that can cause toxicity at high levels, such as iron and vitamin A.

If you think you may need a prenatal vitamin but aren’t planning to get pregnant, talk to your doctor or other healthcare provider for guidance.

Taking prenatal vitamins before you get pregnant can ensure your body is in the optimal state to support a healthy pregnancy. Experts recommend beginning a prenatal vitamin three months before the start of pregnancy, to help your body build up a supply of nutrients.

For more insight on optimizing your nutrition during pregnancy, learn how the Genate Test and nutrigenetic counseling from registered dietitians can help you develop a personalized nutrition plan that meets your needs. 

Learn more about the science behind our mission to support expectant mothers’ nutrition and health every step along the way of their pregnancy journey. Then meet our team of medical experts and professionals dedicated to ensuring your baby is healthy and happy from the start.

This article is not intended as medical advice to treat or diagnose any health condition, but rather as educational health information for the general public. It should not be used as a substitute for individualized medical care from your healthcare provider. 

Libby Pellegrini, MMS, PA-C, is a professionally trained journalist and physician assistant. She has worked in numerous healthcare settings, including the rural United States, an inner-city Level I trauma center, and several suburban acute care centers. It was during her time at a functional medicine clinic in Southeast Asia that she developed an interest in the role of SNPs in personalized genetic evaluation and discovered how gene-guided nutritional counseling can enhance individual health outcomes.

Libby graduated Magna Cum Laude from Northwestern’s Medill School of Journalism, and her medical writing has appeared in a number of outlets, including WebMD, RxSaver, KevinMD, NPHIC, and Men’s Health.

Website: https://libbypellegrini.com/ 

LinkedIn: https://www.linkedin.com/in/libby-pellegrini-pa-c/

1. When does brain development begin? Zero to Three. https://www.zerotothree.org/resource/when-does-brain-development-begin/ Published May 24, 2014. Accessed October 16, 2023. 
   
   
2. Irvine N, England-Mason G, Field CJ, Dewey D, Aghajafari A. Prenatal folate and choline levels and brain and cognitive development in children: a critical narrative review. Nutrients. 2022;14(2):364. https://doi.org/10.3390/nu14020364
   
   
3. Neural tube defects. Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/neural-tube-defects Accessed October 16, 2023.
   
   
4. Iron-deficiency anemia. Office on Women’s Health. https://www.womenshealth.gov/a-z-topics/iron-deficiency-anemia Updated February 22, 2021. Accessed October 16, 2023.
   
   
5. Iron is important during pregnancy. Oklahoma State University. https://extension.okstate.edu/fact-sheets/iron-is-important-during-pregnancy.html Published April 2022. Accessed October 16, 2023. 
    
6. Prenatal vitamins: why they matter, how to choose. Mayo Clinic. https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/prenatal-vitamins/art-20046945 Published April 19, 2022. Accessed October 16, 2023.
   
   
7. Good health before pregnancy: pre pregnancy care. American College of Obstetrics and Gynecology. https://www.acog.org/womens-health/faqs/good-health-before-pregnancy-prepregnancy-care Updated December 2021. Accessed September 24, 2023.