What is the richest source of folate? Your guide to dietary B9

October 3, 2025 •

4 min read

According to the National Institutes of Health, what is the richest source of folate per serving is a complex question with multiple answers, but beef liver often ranks highest. Fortunately, numerous other foods can supply this essential B vitamin, including exceptionally rich plant-based sources like cooked edamame and lentils. A balanced diet featuring these items is key to preventing deficiency and promoting overall health.

Quick Summary

This article explores the most concentrated natural and common dietary sources of folate, distinguishing between naturally occurring folate and synthetic folic acid. It details a variety of foods rich in vitamin B9, explains its crucial health functions, and provides practical advice for increasing intake through food choices and fortification.

Key Points

Top Sources: Beef liver is the most concentrated source per weight, while legumes like lentils and edamame are exceptionally high per serving and common in many diets.
Folate vs. Folic Acid: Folate is the natural form found in food, whereas folic acid is the more stable, synthetic version used in supplements and fortified foods.
Crucial for Pregnancy: Adequate folic acid intake is essential before and during early pregnancy to prevent neural tube defects in infants.
Dietary Strategies: To maximize intake, focus on a varied diet rich in leafy greens, beans, and fortified grains, and use cooking methods like steaming to minimize folate loss.
Deficiency Signs: Symptoms of folate deficiency include fatigue, weakness, and megaloblastic anemia.

Understanding the Most Concentrated Folate Sources

When considering the question, "what is the richest source of folate?" beef liver is frequently cited as the most concentrated option available. A 3-ounce serving of braised beef liver provides a very high amount, offering a significant portion of the recommended daily intake. However, for those who do not consume organ meats, many common and accessible plant-based foods are also packed with this vital nutrient. Legumes like cooked lentils and edamame, for instance, are incredibly potent sources per serving and are often more practical for regular dietary inclusion.

The Difference Between Folate and Folic Acid

It is important to understand the distinction between folate and folic acid, as the terms are often used interchangeably. Folate is the naturally occurring form of vitamin B9 found in food, while folic acid is the synthetic, man-made version used in supplements and to fortify foods. Folic acid is generally more stable and is better absorbed by the body than the natural form. This is why public health initiatives, such as the fortification of grain products like cereals, bread, and pasta in the US since 1998, have been so successful in increasing population-wide intake. However, some individuals may have genetic variations that affect their ability to process folic acid, making natural food sources or specialized supplements more suitable.

Why Your Body Needs Folate

Folate plays a crucial role in many essential bodily functions. It is necessary for the production of red blood cells and for the synthesis and repair of DNA, the genetic material that guides all cellular activities. A deficiency can lead to a type of anemia called megaloblastic anemia, which causes symptoms like fatigue and weakness.

Benefits Beyond Anemia Prevention

Cell Growth and Function: Folate is vital for healthy cell division and tissue growth throughout the body.
Pregnancy Health: Adequate folate intake is particularly critical before and during early pregnancy. It helps prevent serious birth defects of the baby's brain and spine, known as neural tube defects (NTDs).
Homocysteine Levels: Folate, along with vitamins B6 and B12, helps control levels of homocysteine in the blood. High levels of this amino acid may increase the risk of cardiovascular disease.

Top Dietary Sources of Folate

While beef liver is the richest in concentration, a diverse diet is the best approach to meeting your folate needs. Here is a list of excellent sources:

Legumes: Lentils, chickpeas, black beans, edamame, and black-eyed peas are among the highest plant-based sources.
Dark Leafy Greens: Spinach, turnip greens, collard greens, and romaine lettuce offer substantial amounts.
Asparagus: A serving of boiled asparagus provides a significant portion of the daily value.
Broccoli: Both raw and cooked broccoli are good sources.
Avocado: This fruit is a fantastic source of folate.
Fruits: Citrus fruits like oranges and papaya, along with bananas and strawberries, contribute to your daily intake.
Eggs: One large hard-boiled egg provides a modest but useful amount of folate.
Nuts and Seeds: Peanuts, sunflower seeds, and almonds are good choices for snacking.
Fortified Grains: Breakfast cereals, breads, rice, and pasta that are labeled as 'enriched' are fortified with folic acid to help prevent deficiency.

Factors Affecting Folate Content and Intake

When planning your meals, consider how food preparation can affect folate levels. Since folate is water-soluble and sensitive to heat, cooking methods can significantly impact its concentration. For example, boiling vegetables can reduce folate content by 50–80%, as the nutrient can leach into the water. Opting for raw preparation, steaming, or stir-frying can help preserve more of the vitamin. Food processing, such as chopping leafy greens, might also increase bioavailability slightly.


Feature	Folate	Folic Acid
Source	Found naturally in foods like leafy greens, legumes, and fruits.	Synthetic form, used in supplements and to fortify grains like cereals and bread.
Absorption	Absorbed less efficiently by the body; can be lost during cooking.	More easily absorbed by the body, with about 85% bioavailability from supplements.
Stability	Less stable, susceptible to breakdown by heat, light, and oxygen.	More stable and robust, which is why it is used for fortification.
Purpose	Provides natural dietary B9, essential for various bodily functions.	Used to prevent and treat folate deficiency, especially important for preventing neural tube defects.

Potential Risks and Addressing Folate Deficiency

While getting enough folate is crucial, taking excessive amounts of folic acid (over 1,000 mcg per day) from supplements can be a concern. High doses can mask a vitamin B12 deficiency, potentially leading to neurological damage if the underlying B12 issue goes undiagnosed and untreated. This is why it is generally best to obtain folate from a varied diet whenever possible, with supplementation reserved for specific cases or as advised by a healthcare provider.

Signs of folate deficiency can include fatigue, pale skin, irritability, diarrhea, and a sore or red tongue. If you suspect a deficiency, it is best to consult a healthcare provider for a proper diagnosis and treatment plan, which may involve folic acid supplements and dietary changes.

Conclusion: Prioritizing a Varied Diet

Ultimately, there is no single perfect answer to what is the richest source of folate for every person. While concentrated sources like beef liver and legumes provide a powerful punch, the best strategy is a well-rounded diet that incorporates a variety of high-folate foods. By prioritizing leafy greens, legumes, fortified grains, and fruits, you can ensure a steady and reliable intake of this vital B vitamin, supporting your overall health and preventing deficiencies. For women who are pregnant or planning to be, supplementation with folic acid is a crucial step recommended by health professionals to protect against serious birth defects.

For more information on folate and its health benefits, you can visit the Mayo Clinic's guide on folate.

Frequently Asked Questions

Beef liver is often cited as the single most concentrated natural source of folate per weight. However, per typical serving, plant-based foods like cooked edamame and lentils are extremely high in folate.

Folate is the natural form of vitamin B9 found in foods, while folic acid is the synthetic form used in supplements and fortified foods. Folic acid is more stable and has higher bioavailability than natural folate.

Legumes (lentils, chickpeas, black beans, edamame), dark leafy greens (spinach, collard greens), and asparagus are among the richest plant-based sources of folate.

Cooking methods that use high heat or water, such as boiling, can significantly reduce the folate content of vegetables by causing the nutrient to leach out. Steaming or eating vegetables raw helps preserve more folate.

During pregnancy, folate is critical for the proper development of the baby's brain and spinal cord. Adequate intake helps prevent serious birth defects known as neural tube defects.

Yes, it is possible to get too much folic acid from supplements or fortified foods. A safe upper limit is typically 1,000 mcg per day for adults. High doses can mask a vitamin B12 deficiency and potentially cause other health issues.

Signs of folate deficiency include fatigue, weakness, a sore and red tongue, mouth ulcers, pale skin, and irritability.