Folic acid is the man-made version of the vitamin folate (also known as vitamin B9). Folic acid is manufactured for use in food fortification and most supplements. Folic acid must be converted enzymatically into 5-MTHF. 5-MTHF is the predominant natural dietary folate and the principal form of folate in plasma and cerebrospinal fluid. Supplementation with 5-MTHF directly raises plasma folate levels more rapidly than an equivalent dose of folic acid

Folate helps the body make healthy red blood cells and is directly linked to supporting the correct development of an unborn baby's brain, skull and spinal cord. 5-MTHF is also involved in the production of serotonin and melatonin and it is indirectly involved in the synthesis of DNA.

It is important for a woman of childbearing age to get enough folic acid – not just those women who are planning to become pregnant. Those dealing with high levels of stress, and anyone interested in longevity might also find 5-MTHF supplementation beneficial.