Methylfolate (5-MTHF) is a natural folate form that is directly bioavailable and therefore easy for the body to use. It does not require any extra metabolic steps to be absorbed and enter circulation once ingested. This makes it superior to folic acid, which needs to be activated before it can be used by the body. 5-MTHF does also not cause unmetabolized folic acid (UMFA) to raise in plasma, which has been associated with the risk of cancer, and autism spectrum disorder. 

Folate is an essential, water-soluble B vitamin and as such plays an essential role for human body from preconception until old age. The vital functions of folate include:

• Providing building blocks for DNA biosynthesis needed for cell growth, renewal, and function
• Providing methyl groups for more than 100 cellular reactions such as DNA methylation which regulates gene expression by epigenetic mechanisms
• Ensuring normal metabolism and plasma concentrations of the toxic amino acid homocysteine
• Participating in the build-up of amino acids needed to produce cellular proteins 

Sufficient folate levels are crucial during all stages of life. For example, during pregnancy it reduces the risk of growth retardation and birth anomalies and in older adults it promotes health of the nervous system, hematopoietic system, cardiovascular system, gastrointestinal system, and bone.*

• The recommended daily intake of folate for adults is 400 µg/day.
• Recommended intake increases during pregnancy and lactation (500 – 800 µg/day) to support the needs of the fetus and infant, respectively.
• Compared to adults, infants require higher amounts of folate per kg body weight.

Because folate is not produced by the human body, it must be obtained from dietary sources to maintain normal body functions. Folate is naturally present in some foods such as vegetables and animal foods such as meat and is added to foods and food supplements to enable a greater portion of the population to meet the daily requirements of this nutrient.

Meeting the daily recommended intake of folate via the natural diet can be challenging. For example, achieving 400 µg/day via the diet would require consumption of one kilogram of spinach or 500 grams of liver per day. In addition, folate exists as large complexes with polyglutamate in natural foods and proper absorption from the diet requires it to be released from these complexes. Release of folate from its polyglutamate binding could be a rate limiting step in the absorption process. Thus, the bioavailability of dietary folate is not as efficient as when folate is taken in free forms from fortified foods or food supplements. Approximately 5 to 10 mg of folate are stored in the human liver, an amount that is sufficient to support bodily needs for up to three months. If folate intake is insufficient or folate is not properly absorbed, a deficiency can develop within approximately three months.