Folate, or folic acid, is a very important B-vitamin involved in cell creation and preservation, as well as the protection of DNA from mutations that can cause cancer. It is commonly found in leafy green vegetables, but is also present in many other foods such as fruit, dairy products, eggs and meat. Folate is imperative during pregnancy as a deficiency will cause neural tube defects in the offspring. Many countries around the world now fortify foods with folic acid to prevent such defects. This pathway begins in the extracellular space, where folic acid is transported into the cell through a proton-coupled folate transporter. From there, dihydrofolate reductase converts folic acid into dihydrofolic acid. Dihydrofolic acid is then created into tetrahydrofolic acid through dihydrofolate reductase. Tetrahydrofolic acid then sparks the beginning of many reactions and subpathways including purine metabolism and histidine metabolism. There are two reactions that tetrahydrofolic acid undergoes, the first being the catalyzation into tetrahydrofolyl-[glu](2) through the enzyme folylpolyglutamate synthase in the mitochondria. Then, tetrahydrofolyl-[glu](2) becomes tetrahydrofolyl-[glu](n) through folylpolyglutamate synthase. The cycle ends with tetrahydrofolyl-[glu](n) reverting to tetrahydrofolyl-[glu](2) in the lysosome through the enzyme gamma-glutamyl hydrolase. The second reaction that begins with tetrahydrofolic acid sees tetrahydrofolic acid turned into 10-formyltetrahydrofolate through c-1-tetrahydrofolate synthase. This loop is completed by cytosolic 10-formyltetrahydrofolate dehydrogenase reverting 10-formyltetrahydrofolate back to tetrahydrofolic acid. Folate is not stored in the body for very long, as it is a water soluble vitamin and is excreted through urine, so it is important to ingest it continually, as your body’s level of folate will decline after a few weeks if the vitamin is avoided.

Folate Metabolism References