Korkealaatuisen B-vitamiinivalmisteen ero halpamalliin näkyy folaatin laadussa. Halvoissa on foolihappoa, joka saattaa aiheuttaa hyötyjen lisäksi joitain haittoja ainakin isompina määrinä. Korkeampilaatuisissa tuotteissa on käytetty metyylifolaattia.
Studies comparing L-5-methyl-THF and folic acid have found that the two compounds have comparable physiological activity, bioavailability and absorption at equimolar doses. Bioavailability studies have provided strong evidence that L-5-methyl-THF is at least as effective as folic acid in improving folate status, as measured by blood concentrations of folate and by functional indicators of folate status, such as plasma homocysteine. Intake of L-5-methyl-THF may have advantages over intake of folic acid. First, the potential for masking the haematological symptoms of vitamin B(12) deficiency may be reduced with L-5-methyl-THF. Second, L-5-methyl-THF may be associated with a reduced interaction with drugs that inhibit dihydrofolate reductase.
Health is a crown worn by the healthy people on their heads.