The premium folate did not beat the cheap one
Over 24 weeks in 144 women, 416 micrograms of methylfolate lowered homocysteine no more than 400 micrograms of plain folic acid. Doubling the methylfolate dose did not move it further.
What the study found
Methylfolate lowered homocysteine no better than plain folic acid
The premium form was put up against the cheap one and drew. Over 24 weeks in 144 women, 416 micrograms of methylfolate, the pre-activated form, lowered homocysteine no more than 400 micrograms of plain folic acid did. Doubling the methylfolate dose did not move homocysteine any further.
The caveat · A blood marker, not birth outcomes
Homocysteine is a blood marker, not a birth outcome: this trial says nothing about whether either form prevents a neural tube defect. The 144 women were split across four arms, so each is small, and none was selected by genotype, which is the comparison the marketing claim actually turns on. A co-author affiliation with the maker of the methylated preparation is worth checking before the result is quoted in either direction.
What we don't know
Whether methylfolate beats plain folic acid in carriers of the MTHFR variant, a folate-activating enzyme gene, is not shown. The trial cited for it had no folic acid arm; the one that compared the two forms found no advantage.