Food supplement manufacturers often use the term folate for something different from “pure” folic acid: in chemistry, folate refers to the deprotonated ion, and folic acid to the neutral molecule—which both coexist in water. The International Union of Pure and Applied Chemistry and the International Union of Biochemistry and Molecular Biology state that folate and folic acid are the preferred synonyms for pteroylglutamate and pteroylglutamic acid, respectively.
Folate indicates a collection of “folates” that is not chemically well-characterized, including other members of the family of pteroylglutamates, or mixtures of them, having various levels of reduction of the pteridine ring, one-carbon substitutions and different numbers of glutamate residues.
Folic acid is synthetically produced, and used in fortified foods and supplements on the theory that it is converted into folate. However, folic acid is a synthetic oxide form, not significantly found in fresh natural foods. To be used, it must be converted to tetrahydrofolate (tetrahydrofolic acid) bydihydrofolate reductase (DHFR). Increasing evidence suggests that this process may be slow in humans.
Vitamin B9 Is essential for numerous bodily functions. Humans cannot synthesize folates de novo; therefore, folic acid has to be supplied through the diet to meet their daily requirements. The human body needs folate to synthesize DNA, repair DNA, and methylated DNA as well as to act as a cofactor in certain biological reactions. It is especially important in aiding rapid cell division and growth, such as in infancy and pregnancy. Children and adults both require folate to produce healthy red blood cells and prevent anemia.
Folate and folic acid derive their name from the Latin word folium, which means “leaf”. Foliates occur naturally in many foods and, among plants, are especially plentiful in dark green leafy vegetables.
A lack of dietary folates can lead to folate deficiency. A complete lack of dietary folate takes months before deficiency develops as normal individuals have about 500–20,000 micrograms (µg) of folate in body stores. This deficiency can result in many health problems, the most notable one being neural tube defects in developing embryos—a relatively rare birth defect affecting 300,000 (0.2%) births globally each year and 3,000 pregnancies in the United States each year.Common symptoms of folate deficiency include diarrhea, macrocytic anemia with weakness or shortness of breath, nerve damage with weakness and limb numbness (peripheral neuropathy),pregnancy complications, mental confusion, forgetfulness or other cognitive deficits, mental depression, sore or swollen tongue, peptic or mouth ulcers, headaches, heart palpitations, irritability, and behavioral disorders. Low levels of folate can also lead to homocysteine accumulation. Low levels of folate have been associated with specific cancers. However, it is not clear whether consuming recommended (or higher) amounts of folic acid—from foods or in supplements—can lower cancer risk in some people.