Understanding the Alternatives: What is another name for methylated folate?

November 14, 2025 •

4 min read

Approximately 40% of the population carries a genetic variation that affects folate metabolism, making it difficult for their bodies to convert synthetic folic acid into its active, methylated form. This highlights the importance of understanding the active form, so what is another name for methylated folate?

Quick Summary

Methylated folate is also known as L-methylfolate or 5-MTHF and is the biologically active form of vitamin B9 that the body can use directly without conversion.

Key Points

Name Alternatives: Methylated folate is also known as L-methylfolate and 5-MTHF (5-methyltetrahydrofolate), both referring to the active form of vitamin B9.
Bioactive Form: Unlike synthetic folic acid, methylated folate is the biologically active version, meaning it can be used directly by the body without needing enzymatic conversion.
MTHFR Gene Variation: Many people have a genetic mutation that impairs their ability to convert folic acid into its active form, making methylated folate supplements a more effective alternative.
Health Benefits: Key functions include supporting DNA synthesis, regulating mood via neurotransmitter production, and converting harmful homocysteine into beneficial methionine.
Superior Absorption: Because it is already in its usable state, methylated folate offers superior bioavailability compared to folic acid, benefiting individuals with metabolic defects.
Found in Diet and Supplements: While the body produces it from natural food folate, active methylated folate is also available in supplements for those who need higher levels or cannot metabolize folic acid efficiently.

What Exactly Is Methylated Folate?

Methylated folate, most commonly referred to as 5-MTHF (5-methyltetrahydrofolate), is the active form of vitamin B9. Unlike synthetic folic acid, which is found in many fortified foods and supplements, methylated folate is readily usable by the body's cells. This active form is crucial for numerous vital biological processes, including DNA synthesis and repair, the production of neurotransmitters, and the detoxification pathway known as methylation. While natural folate from food is converted to 5-MTHF in the digestive system, a genetic variation affecting the MTHFR enzyme can impair the body's ability to activate synthetic folic acid.

Another Name for Methylated Folate: L-Methylfolate

L-methylfolate is another widely used name for methylated folate, particularly in a supplemental context. The 'L' in the name signifies that it is the biologically active and most bioavailable isomer. This means it is immediately ready to be used by the body, bypassing the need for a multi-step enzymatic conversion process. For individuals with a genetic polymorphism, supplementing with L-methylfolate is often recommended as it ensures they receive the active nutrient directly.

Another Name for Methylated Folate: 5-MTHF

5-MTHF is the scientific abbreviation for 5-methyltetrahydrofolate, which is the full chemical name for methylated folate. You may also see it written as L-5-MTHF or (6S)-5-MTHF on some supplement labels. These are simply different ways of scientifically denoting the same active compound. As the predominant physiological form of folate in the blood, 5-MTHF is the form that actually enters the body's cells and carries out its metabolic functions.

Comparison of Folate Forms

To better understand the differences, here is a comparison table outlining the key forms of vitamin B9.


Feature	Folic Acid	Natural Folate	Methylfolate (L-Methylfolate, 5-MTHF)
Source	Synthetic, not found naturally in foods.	Occurs naturally in foods like leafy greens and legumes.	Bioactive form, produced from natural folate and also available as a supplement.
Absorption	Must be converted to 5-MTHF, which can be inefficient in some individuals.	Primarily converted to 5-MTHF in the intestine before entering the bloodstream.	Directly absorbed and ready for cellular use; bypasses conversion.
Metabolism	Requires the enzyme dihydrofolate reductase (DHFR) for conversion to the active form.	Undergoes a normal metabolic pathway in the body, which involves enzymatic conversion.	Requires no enzymatic conversion and is immediately available to the body.
Bioavailability	Variable, especially for those with MTHFR gene mutations.	Good, but dependent on proper digestion and conversion.	Superior, as it is the most bioactive form that can cross the blood-brain barrier.

Key Benefits of Methylated Folate

Using methylated folate offers several important health benefits, especially for those who struggle with folate metabolism.

Supports DNA Health: Methylfolate is essential for DNA synthesis and repair, promoting healthy cell division and growth.
Enhances Cognitive Function and Mood: It plays a crucial role in synthesizing neurotransmitters like serotonin, dopamine, and norepinephrine, which are vital for regulating mood, focus, and overall cognitive health.
Regulates Homocysteine Levels: By participating in the methylation cycle, it helps convert homocysteine into methionine, an essential amino acid. High homocysteine levels can pose risks for cardiovascular disease, so this conversion is vital for heart health.
Aids in Detoxification: Methylation is critical for your body's detoxification processes. Adequate methylfolate helps fuel these cycles, assisting in the breakdown of toxins.
Crucial for Pregnancy: Sufficient levels of methylated folate are essential for fetal development during early pregnancy and can help prevent neural tube defects.

The Role of the MTHFR Gene

Research indicates that many individuals have a single nucleotide polymorphism (SNP) in the methylenetetrahydrofolate reductase (MTHFR) gene. This genetic variation can significantly reduce the body's ability to convert synthetic folic acid into its active, usable form, 5-MTHF. For these individuals, supplementing with folic acid may be less effective and could lead to unmetabolized folic acid accumulating in the bloodstream, which is an undesirable outcome. This is why methylated folate supplements have become a preferred alternative for many health practitioners and patients alike.

How to Get More Methylated Folate

There are two primary ways to ensure you have adequate levels of methylated folate:

Dietary Sources

Consuming a diet rich in natural folate is the first step. Foods high in naturally occurring folate include:

Leafy green vegetables (spinach, kale, arugula)
Legumes (lentils, chickpeas, beans)
Eggs
Citrus fruits
Beef liver

Supplementation

For those with impaired metabolism or specific health needs, a supplement may be necessary. When choosing a supplement, look for one that specifies L-methylfolate, 5-MTHF, or a branded form like Metafolin or Quatrefolic to ensure you are getting the active, bioavailable form. It is often recommended to take methylated folate as part of a complete B-complex vitamin, as it works synergistically with other B vitamins, particularly B12.

Considerations and Precautions

While generally safe, there are some considerations when taking methylated folate. High doses may not be suitable for everyone, and it's essential to consult a healthcare professional, especially if you have a history of bipolar disorder, epilepsy, or cancer. Furthermore, a folate supplement can mask a vitamin B12 deficiency, so it's often wise to have your B12 levels checked or take a B-complex containing both. For more detailed information on folate metabolism, including how different forms are used by the body, an authoritative resource can be found at the National Institutes of Health.

Conclusion

Methylated folate is the biologically active form of vitamin B9 that is directly usable by the body. Its common alternative names, L-methylfolate and 5-MTHF, are crucial to recognize, especially for individuals with genetic variations affecting folate metabolism. By understanding the distinction between folic acid and these bioactive forms, consumers can make more informed choices about their nutritional supplementation to support various physiological functions, from brain health and mood to DNA synthesis and cardiovascular wellness.

Frequently Asked Questions

Yes, L-methylfolate and 5-MTHF are different names for the same active, bioavailable form of folate (vitamin B9). L-methylfolate is often used on supplement labels, while 5-MTHF is the scientific abbreviation for 5-methyltetrahydrofolate.

No, they are not the same. Folic acid is the synthetic, inactive form of vitamin B9 that requires conversion by the body to become active. Methylated folate is the already-converted, active form that the body can use directly.

Benefits include supporting healthy DNA synthesis and repair, regulating homocysteine levels for heart health, assisting in neurotransmitter production for mood regulation, and supporting the body's detoxification processes.

Individuals with a genetic variation of the MTHFR enzyme often benefit most from methylated folate, as their conversion of folic acid is inefficient. This variation can be identified through genetic testing. Many practitioners also recommend it as a universally absorbable option.

You can get natural folate from foods like leafy greens, legumes, and eggs, which your body converts to methylated folate. However, for people with impaired metabolism or increased needs, supplementation with methylated folate may be necessary.

Excess methylated folate is water-soluble and generally excreted, and it does not have a set Tolerable Upper Intake Level, unlike folic acid. However, it is always recommended to consult a doctor before taking any supplement, especially at high doses.

The MTHFR gene mutation is a common genetic variation that can decrease the efficiency of the MTHFR enzyme, which is required to convert folate into its active 5-MTHF form. This can lead to lower active folate levels in the body.