{{chembox | Name = Folic acid | ImageFile = Folicacid2.png | ImageSize = 250px | ImageName = Folic acid | IUPACName = (2S)-2-[(4-{1amino}phenyl)formamido]pentanedioic acid | OtherNames = N-​(4-​{2​amino}​benzoyl)-​L-​glutamic acid; pteroyl-L-glutamic acid; Vitamin B₉; Vitamin M; Folacin | Section1 = | Section2 = | Section7 = }}

Folic acid (also known as Vitamin B9 or Folacin) and Folate (the naturally occurring form) are forms of the water-soluble Vitamin B₉. Vitamin B9 (Folic acid and Folate inclusive) is essential to numerous bodily functions ranging from nucleotide synthesis to the remethylation of homocysteine. It is especially important during periods of rapid cell division and growth. Both children and adults require folic acid to produce healthy red blood cells and prevent anemia. Folate and Folic acid derive their names from the Latin word folium (leaf).

Folate in foods and other sources

Leafy vegetables such as spinach, turnip greens, lettuces, dried/fresh beans and peas, fortified cereal products, sunflower seeds and certain other fruits and vegetables are rich sources of folate. Liver and liver products also contain high amounts of folate, as does baker's yeast. Some breakfast cereals (ready-to-eat and others) are fortified with 25% to 100% of the recommended dietary allowance (RDA) for folic acid. A table of selected food sources of folate and folic acid can be found at the USDA National Nutrient Database for Standard Reference. Folic acid is added to grain products in many countries, and in these countries fortified products make up a significant source of folate . Because of the difference in bioavailability between supplemented folic acid and the different forms of folate found in food, the dietary folate equivalent (DFE) system was established. 1 DFE is defined as 1 μg of dietary folate, or 0.6 μg of folic acid supplement. This is reduced to 0.5 μg of folic acid if the supplement is taken on an empty stomach.

History

A key observation by researcher Lucy Wills in 1931 led to the identification of folate as the nutrient needed to prevent anemia during pregnancy. Dr. Wills demonstrated that anemia could be reversed with brewer's yeast. Folate was identified as the corrective substance in brewer's yeast in the late 1930s and was first isolated in spinach leaves by Mitchell and others in 1941 . Bob Stokstad isolated the pure crystalline form in 1943, and was able to determine its chemical structure while working at the Lederle Laboratories of the American Cyanid Company. This led to the subsequent synthesis of folic acid in 1945, by Dr. Yellapragada Subbarao and many others.