Methylated B-Vitamins vs. Synthetic — Why It Matters
If you have an MTHFR variant — and a lot of people do — synthetic folic acid and cyanocobalamin can sit in your bloodstream without ever activating.
Synthetic B-vitamins — folic acid, cyanocobalamin — were a 1940s engineering win. Stable, cheap, easy to fortify into bread. They get the population to a baseline that prevents frank deficiency at scale.
They depend on a conversion step. Folic acid → dihydrofolate → tetrahydrofolate → methylfolate. Cyanocobalamin → methylcobalamin or adenosylcobalamin. The conversion happens via enzymes that — for a non-trivial fraction of the population — work less efficiently than the textbook assumes.
Folic acid is the substrate. Methylfolate is the active form. The difference is whether your cells can actually use it.
MTHFR variants (C677T being the famous one) reduce the activity of one of the key conversion enzymes by 30–70%. Roughly 30–40% of people of European descent carry at least one copy. For them, eating fortified cereal at the RDA can still leave them functionally low on the active methylated form.
Methylated B-vitamins skip the conversion. L-methylfolate is the active form your cells use directly. Methylcobalamin is the active form of B12 your nervous system uses. The labs and clinical literature both support the case for going straight to the methylated forms when supplementation matters.
In our drips and our B12 shot, methylcobalamin is the default. Not because every client has an MTHFR variant — most don't — but because the cost difference is small and the worst case is "your body would have converted it anyway." Best case, you skip a bottleneck.
If you've been supplementing B-complex for years without noticeable effect, the form might be the answer.
