According to the NIH, methylfolate may be more absorbable for more people.
How does methylfolate stack up against folic acid? While large-scale studies haven't yet been conducted with methylfolate to directly compare it to folic acid, the studies we do have show that methylfolate is as good as (or better than) folic acid in terms of increasing folate levels in red blood cells and serum— meaning a comparable amount of folate is available in the body after taking it.

Magnafolate® L Methylfolate(active folate) raw material/L Methylfolate(active folate) ingredient.