5 methyltetrahydrofolic acid

5-Methyltetrahydrofolic acid (5-Methyl THF) 是四氢叶酸的甲基化衍生物，具有生物活性。5-Methyltetrahydrofolic acid 是主要的天然膳食叶酸，是血浆和脑脊液中叶酸的主要形式。

Levomefolate calcium pentahydrate is the calcium salt of 5-methyltetrahydrofolic acid, a biologically active form of folic acid that functions, in conjunction with Vitamin B12. Levomefolate is included in formulations of certain oral contraceptives to ens