Understanding Folate, Folic Acid, and L-Methylfolate During Pregnancy

November 14, 2023

Written by Gia Eapen, MD

Medically reviewed by

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Key Points

  • Folate (Vitamin B9) plays a critical role during pregnancy, aiding in the growth and development of the fetus.
  • Folate, Folic acid, and L-Methylfolate are all forms of Vitamin B9, but they differ in their metabolic activity and sources.
  • Folic acid supplementation during pregnancy can help prevent neural tube defects and other congenital abnormalities.
  • The enzyme MTHFR plays a significant role in the metabolism of folate, and genetic variations can affect the bioavailability of folate.
  • Meeting the daily recommended intake of folate during pregnancy can be challenging through diet alone, making supplementation often necessary.

Pregnancy is a time of rapid growth and development for both you and your baby. One nutrient that plays a critical role in this process is folate (vitamin B9), which is required for DNA replication, amino acid synthesis, and vitamin metabolism. The demand for folate significantly increases during pregnancy, contributing to the development of your baby. 

Understanding Folate, Folic Acid, and L-Methylfolate

Before we get into the nitty-gritty, let's make sure we understand some important terms. Folate, also known as vitamin B9, is a type of nutrient that our bodies can't produce on their own. That means we need to get it from the foods we eat or from supplements.

Folic acid is a type of folate that's made in a lab. It's found in some foods that have been fortified, or have extra nutrients added, as well as in vitamin supplements. But here's the catch - our bodies can't use folate or folic acid directly. They need to be changed into a different form that our bodies can use.

That form is called L-5-Methyltetrahydrofolate (or L-methylfolate for short). This is the main type of folate that our bodies use in different biological processes. To become this usable form, folic acid goes through a couple of changes, first becoming DHF and then THF. These changes are helped along by an enzyme called DHF reductase. Finally, THF can be converted to L-methylfolate, the form our bodies can use.

Folate Versus Folic Acid

While "folic acid" and "folate" are terms often used interchangeably, they aren't the same. Folate is a general term encompassing the different forms of Vitamin B9, which includes folic acid, dihydrofolate (DHF), tetrahydrofolate (THF), 5,10-methylenetetrahydrofolate (5,10-MTHF), and 5-methyltetrahydrofolate (5-MTHF).

Folic acid, specifically, is the synthetic form of folate used in supplements and fortified foods such as rice, pasta, bread, and certain breakfast cereals. Numerous scientific studies worldwide have proven the effectiveness of folic acid in preventing neural tube defects.

Conversely, natural folate is found in foods such as leafy green vegetables, citrus fruits, and beans. While a balanced diet rich in natural folate is recommended, it is challenging for most women to meet the daily recommended amount of folate through food alone. For more personalized advice on how to enhance your dietary folate intake, consider booking an appointment with a Registered Dietitian through Fay.

Folic Acid, MTHFR, and Pregnancy

Folic acid supplementation has long been known to reduce the risk of neural tube defects. Recent studies suggest it may also protect against congenital heart defects and preterm birth. Although the relationship between MTHFR genetic polymorphisms and folate metabolism isn't well understood, it's thought that women with known MTHFR mutations may benefit from direct supplementation with L-methylfolate. Although additional studies are needed to define precise timing, dosing, and formulation, existing data suggest that dietary folic acid supplementation is beneficial for all reproductive-aged women.

Folic acid is a critical nutrient for pregnant women due to its involvement in various biological processes, including DNA replication and amino acid synthesis. With increasing demands during pregnancy, ensuring an adequate intake of this nutrient is paramount to prevent potential abnormalities in both mothers and fetuses.

As with any supplementation during pregnancy, always consult with your healthcare provider to make the best decisions for your health and the health of your baby. If you need more guidance on this matter, talk to a Registered Dietitian at Fay.

The views expressed by authors and contributors of such content are not endorsed or approved by Fay and are intended for informational purposes only. The content is reviewed by Fay only to confirm educational value and audience interest. You are encouraged to discuss any questions that you may have about your health with a healthcare provider.


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Gia Eapen, MD

Written by Gia Eapen, MD

Dr. Gia Eapen is a skilled Obstetrics and Gynecology (OB/GYN) physician at Case Western/MetroHealth. A Northwestern University alumna, she pursued her medical degree at the University of Vermont, fostering a deep understanding of women's health and reproductive medicine. She combines her comprehensive knowledge with a dedication to patient-centered care, embodying a commitment to enhancing healthcare standards in her field.


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