Where to Find Methylfolate: Essential Sources for Optimal Health

January 10, 2026 •

4 min read

Over 40% of the population carries a genetic variation that affects the body's ability to convert folic acid into methylfolate. Because of this, it is important to know where to find this crucial nutrient in the diet and through supplementation.

Quick Summary

Methylfolate, the active form of folate, is naturally found in foods such as leafy greens, legumes, and animal liver. It's also available in highly absorbable supplements, which are especially helpful for those with MTHFR gene variations.

Key Points

Natural Sources: Methylfolate is found naturally in leafy greens, legumes, animal liver, and fermented foods, though heat can degrade it.
Bioavailable Supplements: For efficient absorption, especially with MTHFR mutations, look for supplements containing L-methylfolate (5-MTHF).
Folic Acid vs. Methylfolate: Folic acid is synthetic and requires conversion, while methylfolate is active and immediately usable by the body.
MTHFR Gene Variation: Individuals with this mutation may have impaired folate metabolism, making methylfolate supplementation more effective than folic acid.
Brain and Mood Support: Methylfolate crosses the blood-brain barrier and plays a role in producing neurotransmitters that regulate mood.
Choosing a Supplement: Select products with active L-methylfolate, check for third-party testing, and consider a methylated B-complex for better synergy and safety.
Minimize Side Effects: Start with a low dose and increase gradually to avoid potential side effects like anxiety or irritability.

Methylfolate, also known as 5-MTHF, is the active and usable form of vitamin B9 that is important for many bodily functions, including DNA synthesis, methylation, and neurotransmitter production. Unlike synthetic folic acid, which needs to be converted by enzymes, the body immediately absorbs and uses methylfolate. This makes it a critical source for people who cannot process folate efficiently.

Natural Food Sources of Methylfolate

While the body must convert naturally occurring food folate into methylfolate, some foods contain higher proportions of the active compound than others. However, cooking and processing can reduce folate content, so consuming these foods raw or lightly cooked is ideal.

Leafy Greens: Dark leafy greens like spinach, kale, and romaine lettuce are excellent sources of naturally occurring folate. Studies on spinach found that methylfolate makes up a large portion of its total folate content.
Legumes: Lentils, chickpeas, black beans, and other legumes are rich in folate. Sprouting these legumes can increase both the total folate content and the amount of methylfolate.
Asparagus: This vegetable is a notable source of folate, with a half-cup serving providing a significant portion of the daily value.
Animal Liver: Beef liver contains high levels of folate, including methylfolate.
Fermented Foods: The fermentation process, driven by beneficial bacteria and yeasts, can increase the folate content in certain foods. Examples include miso, kefir, and sauerkraut.
Other Vegetables: Broccoli, cauliflower, Brussels sprouts, and beets also contribute to dietary folate intake.
Eggs: The yolk of an egg contains a concentration of folate derivatives, with a portion of it being the active form.
Fruits: Citrus fruits like oranges and grapefruit, along with berries, are also good sources.

Supplementation: Sourcing Bioavailable Methylfolate

For many, especially those with genetic variations that impede folate metabolism, relying solely on food sources is not enough to achieve optimal levels. This is where supplements provide a direct and highly absorbable option. When looking for a supplement, focus on those that explicitly state they contain the biologically active L-methylfolate (or 5-MTHF).

Patented Forms: Some of the most common and reputable forms of L-methylfolate found in supplements include Metafolin® and Quatrefolic®. These are recognized for their purity and stability.
Supplement Types: Methylfolate can be found in various supplement formats, including capsules, tablets, and sublingual forms (lozenges or drops). The sublingual option allows for quicker absorption under the tongue.
Dosage: Dosages vary depending on individual needs. Standard multivitamins often contain 400 mcg of L-methylfolate, while higher doses (e.g., 1000-15,000 mcg) may be prescribed for specific conditions, such as depression. It is essential to consult a healthcare provider for the right dosage, as excessive intake can cause side effects.

Methylfolate vs. Folic Acid: A Critical Distinction

Understanding the difference between these two forms of vitamin B9 is essential for effective supplementation, particularly for individuals with the MTHFR gene mutation.

Comparison of Methylfolate and Folic Acid


Aspect	Methylfolate (L-5-MTHF)	Folic Acid
Form	The active, naturally occurring form of folate.	A synthetic, oxidized form of folate.
Conversion	Requires no conversion; immediately bioavailable and utilized by the body.	Requires several enzymatic steps in the liver and other tissues for conversion to the active form.
Genetic Variation	Ideal for those with MTHFR mutations, bypassing impaired enzyme activity.	May be less effectively converted in individuals with MTHFR gene variations.
Blood Levels	More reliably increases folate levels, especially for those with conversion issues.	Can lead to unmetabolized folic acid in the bloodstream, particularly at high doses.
Safety	Does not mask vitamin B12 deficiency.	High doses can potentially mask a B12 deficiency, which can have neurological consequences.
Sources	Found naturally in some foods; used in specialized supplements.	A synthetic additive used in fortified foods and standard supplements.

Who Benefits Most from Prioritizing Methylfolate?

While everyone needs folate, certain individuals benefit more from supplementing with or prioritizing the active methylfolate form.

Individuals with MTHFR Mutations: A MTHFR gene variation can significantly reduce the body's ability to convert folic acid into its active form. Supplementing with L-methylfolate directly addresses this issue.
Pregnant and Pre-conception Women: Adequate folate is crucial for preventing neural tube defects. The CDC affirms that folic acid is effective, but L-methylfolate is a superior choice for those with MTHFR variations to ensure proper neural development.
People with Mood Disorders: Methylfolate can cross the blood-brain barrier and is involved in the synthesis of neurotransmitters like serotonin, dopamine, and norepinephrine. It is sometimes used as an adjunct therapy for depression.
Those with High Homocysteine: Methylfolate helps convert homocysteine into methionine. High homocysteine levels are associated with increased cardiovascular risk, so regulating these levels is important.

How to Choose a High-Quality Methylfolate Supplement

When selecting a supplement, consider these factors to ensure you are getting the most effective product.

Identify the Correct Form: Look for labels that specify "L-methylfolate," "L-5-MTHF," or patented forms like "Quatrefolic®". Avoid generic "folate" or "folic acid" unless advised by a doctor.
Check Third-Party Testing: High-quality supplements are often third-party tested to confirm purity, potency, and safety.
Consider a B-Complex: For optimal results and to prevent masking a B12 deficiency, many healthcare practitioners recommend taking methylfolate as part of a methylated B-complex that also contains active B12 (methylcobalamin).
Start Low and Go Slow: Especially for those with sensitivities, beginning with a lower dose and gradually increasing it can help minimize side effects like agitation or anxiety.

Conclusion

Methylfolate is an essential, highly bioavailable form of vitamin B9 that can be sourced from various natural foods, including dark leafy greens, legumes, and liver. For individuals with compromised folate metabolism, particularly those with MTHFR genetic variants, high-quality supplements containing L-methylfolate offer a reliable way to ensure adequate intake. Understanding the difference between methylfolate and folic acid and choosing the right sources supports your body's methylation processes, neurological health, and overall well-being. Consult a healthcare professional to determine the best approach for specific health needs.

Note: For more information on the significance of folate, visit MedlinePlus.

Frequently Asked Questions

Natural folate, which the body converts to methylfolate, comes from foods like leafy greens, legumes, animal liver, eggs, and citrus fruits. Eat vegetables raw or lightly cooked to preserve the folate content.

Yes, fermentation, which uses bacteria and yeast, can increase folate in foods. Fermented foods like kefir, miso, and sauerkraut are good sources of active folate.

Methylfolate is the active form of folate that the body can use directly, while folic acid is a synthetic form that needs to be converted. Methylfolate is a more bioavailable and efficient option for people with genetic variations like MTHFR.

People with MTHFR gene mutations cannot easily convert folic acid and food-based folate into methylfolate. L-methylfolate supplements provide the active form directly, bypassing this genetic impairment and ensuring proper folate utilization.

Yes, some people may experience side effects from too much methylfolate or a rapid increase in dosage. Common symptoms include anxiety, irritability, sleep disturbances, headaches, and nausea. Start with a low dose and consult a doctor.

Methylfolate supplements can be purchased online from retailers like iHerb or Amazon, and also in local health food stores. Reputable brands often use patented forms like Quatrefolic® or Metafolin®.

Yes, L-methylfolate is generally safe during pregnancy and can help reduce the risk of neural tube defects, particularly for those with MTHFR mutations. Consult a healthcare provider to determine the correct dosage and form.

Look for supplements that specify the active form, L-methylfolate (L-5-MTHF), or a patented version like Quatrefolic®. Also, choose products that have undergone third-party testing for purity and consider a methylated B-complex for better overall B-vitamin balance.