Methylated B vitamins are the active forms (5-MTHF folate, methylcobalamin B12) marketed especially for MTHFR variant carriers. Methylated b vitamins are debated — some practitioners emphasize them; mainstream medicine generally considers standard forms adequate for most people.
What’s methylation
The body converts folic acid through several steps to active 5-MTHF. The MTHFR enzyme catalyzes the final step. Common MTHFR variants (C677T particularly) reduce enzyme activity by 30-70% in homozygotes.
The MTHFR controversy
Debated points:
- MTHFR variants are very common (~25% of population homozygous or heterozygous)
- Direct-to-consumer testing has popularized concerns
- Mainstream medicine considers clinical impact generally limited
- Methylated supplementation marketed heavily
When methylated forms might matter
- Documented MTHFR variants with elevated homocysteine
- Specific clinical scenarios (some psychiatric uses)
- Patient preference
When standard forms work fine
- Most MTHFR variant carriers have normal homocysteine
- Standard folic acid supplementation has decades of evidence
- Pregnancy prevention of neural tube defects established with folic acid
Standard vs methylated forms
Folate:
- Folic acid (synthetic): standard, cheap
- L-methylfolate (5-MTHF): active form, more expensive
B12:
- Cyanocobalamin: standard, stable, inexpensive
- Methylcobalamin: active form, slightly different absorption
- Hydroxocobalamin: alternative active form
Frequently Asked Questions
Should I get MTHFR testing?
Mainstream medicine generally doesn’t recommend routine testing.
Are methylated B vitamins better?
For most people, no clear difference. Some clinical scenarios may benefit.
Should I switch to methylated folate?
Most people fine with standard folic acid. Discuss with provider.
What’s L-methylfolate (Deplin)?
Prescription medical food for depression, particularly with MTHFR variants. Some psychiatric use evidence.
Are methylated B vitamins safer?
Safety profiles similar. “Methylated” doesn’t mean safer.
The bottom line on methylated B vitamins
Most people fine with standard B vitamins. Methylated forms reasonable but not necessary for most. Specific clinical scenarios may benefit.