Methylcobalamin B12
The neurologically-active form of B12. Supports myelin synthesis, one-carbon metabolism, and homocysteine clearance. Methylcobalamin is directly usable - cyanocobalamin (used in most supplements) requires hepatic conversion that MTHFR variants cannot perform efficiently.
Mechanism
Vitamin B12 (cobalamin) exists in several forms. Methylcobalamin is the predominant form in neurological tissue - it serves as a cofactor for methionine synthase (methylating homocysteine to methionine) and is required for myelin sheath synthesis and maintenance. Elevated homocysteine, resulting from B12 or folate deficiency, is of interest in homocysteine-metabolism research.
The critical distinction from cyanocobalamin (the cheapest and most widely used form): cyanocobalamin requires two conversion steps in the liver to become methylcobalamin. Individuals with MTHFR gene variants - affecting up to 40% of people - have impaired capacity for these conversions. Methylcobalamin bypasses this entirely, providing the active cofactor directly.
Key Benefits
- Directly bioactive - no hepatic conversion required
- Supports myelin synthesis and neurological function
- Clears homocysteine via methionine synthase pathway
- Bypasses MTHFR conversion step (affects ~40% of people)
- 500mcg = large tissue buffer supporting consistent 25-OH-B12 levels
The Research
Peer-reviewed human trials supporting this ingredient at this dose.
Methylcobalamin B12
500mcgMethylated form - bioactive, no conversion required
Any time of day. The methylated form is directly bioactive - no hepatic conversion required unlike cyanocobalamin. Sublingual or capsule form both effective.