Three families of B9
Folic acid is the synthetic form, the most stable and the best documented, used in fortification and in many supplements. Food folates come from plant extracts. 5-MTHF (5-methyltetrahydrofolate) is the directly active circulating form, present in the catalogue as glucosamine salts (Quatrefolic®) or calcium salts.
Reading the dose
EU labelling may express B9 in micrograms or as "folate equivalents". The NRV is 200 µg. The product page states the exact form (folic acid or 5-MTHF) and the matching dose, the key information when comparing two products.
Why 5-MTHF appears in some formulations
5-MTHF does not require the enzymatic conversion step (notably via MTHFR) that folic acid needs. That is the reason put forward by the manufacturers who choose it, particularly in perinatal complexes and B complexes. Both forms coexist in the catalogue.
How to choose
Check the form (folic acid or 5-MTHF), the dose in micrograms, and whether other B vitamins are included. The Vitamin B9 hub lists products by form.
