L 5 methyl tetrahydrofolate 5 mthf requires no additional metabolic steps to be utilised by the body making it a preferred choice for many indiviuals it is ideal for people whose folate status may be affected by genetic variation 5 mthf does not mask vitamin b12 deficiency and is the only folate that crosses the blood brain barrier folate is has a role in the process of cell division folate contributes to normal homocysteine metabolism as it is essential for methylation