Methylated B Vitamins, MTHFR, and Folic Acid

What Methylated B Vitamins Are

Methylated B vitamins are supplement ingredients that carry a methyl group. On ingredient labels, methylfolate and 5-MTHF represent names for 5-methyltetrahydrofolate. Folic acid is the manmade form of folate. Similarly, methylcobalamin provides a methyl-group form of vitamin B12. Cyanocobalamin is another supplement form of B12. DNA methylation discussed in research on an epigenetic clock is a different topic from consuming a methylated vitamin.

The NHS and MedlinePlus pages cited here do not say that methylated forms work better or worse than other forms.

The MTHFR Gene and Why It Comes Up

The MTHFR gene provides instructions for producing methylenetetrahydrofolate reductase, an enzyme. According to MedlinePlus Genetics, this enzyme converts 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. This converted compound represents the main form of folate found in human blood. The best-studied variant is designated as 677C>T. The enzyme produced from this variant shows reduced activity at higher temperatures. People with 677C>T, particularly in both copies of the gene, have raised homocysteine in the blood (hyperhomocysteinemia). See the homocysteine test page for the lab itself. A second common variation in the gene is 1298A>C. Research evaluations of MTHFR variants in high blood pressure, blood clots, pregnancy loss, psychiatric disorders, and some cancers show mixed results. Associations appear in some studies but fail to emerge in others. The role of MTHFR alterations in these medical disorders remains unclear. Most people with MTHFR variants do not develop neural tube defects. Their children are typically unaffected as well.

What the Public Health Advice Says About Forms

The NHS advises that adults need 200 micrograms of folate each day. Most individuals obtain all the folate they need from a varied and balanced diet. Official guidance states that taking 1 mg or less daily of folic acid supplements is unlikely to cause harm.

Pregnancy recommendations name folic acid to help prevent neural tube defects (NHS). Information from MedlinePlus confirms that getting enough folic acid before and during pregnancy can help prevent major birth defects of the baby's brain or spine. The NHS instructs women who are pregnant, trying to conceive, or could become pregnant to take a 400 microgram folic acid supplement daily. Patients should continue this daily supplement until they reach 12 weeks of pregnancy. Some women with higher risk are advised 5 mg of folic acid a day until 12 weeks after speaking to a doctor; do not start 5 mg without a doctor's advice.

Check B12 Before Raising Folate

The NHS says taking folic acid above 1 mg a day can mask the symptoms of vitamin B12 deficiency, so a clinician decides whether B12 should be checked first. The NHS warns that consuming more than 1 mg of folic acid daily can conceal low B12 symptoms. An untreated deficiency can eventually cause damage to the nervous system. This risk is especially relevant for older adults because absorbing B12 becomes harder as people age. Vitamin B12 helps make red blood cells, keeps the nervous system healthy, releases energy from food, and helps the body use folate. Adults between the ages of 19 and 64 need about 1.5 micrograms of B12 per day. The B12 blood test ranges page explains the test results. The B12 deficiency symptoms page lists the signs. Taking 2 mg or less per day of vitamin B12 in supplements is unlikely to cause harm.

B6 and Other B-Complex Doses

The NHS says vitamin B6 at 200 mg or more a day can cause loss of feeling in the arms and legs (peripheral neuropathy), which usually improves after stopping but can occasionally be permanent. The Department of Health and Social Care advises not taking more than 10 mg a day of B6 in supplements unless a doctor advises it. Check the B6 milligrams on a methylated B complex label.

Food Sources

Folate is a B vitamin found in many foods. Good dietary sources include broccoli, brussels sprouts, leafy green vegetables, peas, chickpeas, and kidney beans. Fortified breakfast cereals also provide folate in the form of folic acid. Adults need 200 micrograms of folate daily. Most people can get the folate they need from a varied, balanced diet.

Good sources of vitamin B12 are meat, fish, milk, cheese, eggs and some fortified breakfast cereals. Vitamin B12 is not found naturally in fruit, vegetables or grains, so vegans may not get enough. A clinician decides whether B12 needs checking. Adults aged 19 to 64 need about 1.5 micrograms of B12 per day.

When to Talk to a Clinician

Talk to a clinician if you are pregnant or planning a pregnancy. The NHS advises taking a 400 microgram folic acid supplement daily until you are 12 weeks pregnant to help prevent neural tube defects such as spina bifida. You should also seek clinical advice if genetic testing reveals an MTHFR variant or if blood tests show raised homocysteine. A clinician decides what any B12 deficiency symptoms mean.

A clinician decides whether a methylated form is needed. Talk to a clinician before deciding whether to take methylated B vitamins.

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