Folic acid is a water-soluble essential vitamin that can be found in many foods, such as leafy greens, citrus fruits and beans and so on. Studies put that folic acid supplementation in the first two months of pregnancy can support the development of the fetal nervous system. In addition, folic acid plays an important role in the metabolism of the same cell.L-5-methyltetrahydrofolic acid is a major and common form of dietary folic acid in human circulation and is essential for human health.As a result, it is a folate that is often transported to peripheral tissues for cellular metabolism. Research reveals, folate is only one that can be passed through the blood-brain barrier.L-5-methyl tetrahydrofolic acid is also a crystalline form of calcium salt, which has the stability needed for supplements and is broadly used in business.Studies have shown that both l-5-methyl tetrahydrofolic acid calcium and folic acid have comparative physiological activity, bioavailability and amount of absorption. However compared to folic acid, l-5-methyl4-hydrofolic acid not only can uncover the deficiency of vitamin B12, but also reduce the interaction between drugs that inhibit the reductase of bihydrofolate.