Folic acid contains a pteridine group linked to para amino benzoic acid and l-glutamic acid (Fig. 8.9). It is slightly soluble in water and stable to heat.
· Folic acid serve as coenzymes in reactions involving the transfer of one carbon units like formyl and methyl groups.
· It participates in the reactions concerned with the synthesis of purine, pyrimidine and nucleic acids.
· It is essential for maturation of red blood cells.
· Folic acid is required for the metabolism of amino acids like histidine.
· Along with vitamin B12, folic acid helps in the trans methylation reactions. eg: uracil to thymine.
Folic acid is particularly present in green leafy vegetables, cauliflower and dried yeast. Egg, liver and kidneys are rich animal sources.
There is no definite requirement for normal human being. However, an increased amount is required during pregnancy and lactation.
Infants - 50 μg / day
Children - 100 - 300 μg / day
Adults - 400 μg/day
Pregnant women - 800 μg / day
Lactating women - 600 μg/day
Absorption of folic acid takes place along the whole length of the mucosa of the small intestine. Folic acid about (5-15 mg/g) is in the liver and folate is also incorporated into the erythrocytes during erythropoiesis (Red blood cells production).
Deficiency of vitamin B12 also leads to functional folic acid deficiency.
· Folic acid deficiency leads to megaloblastic anemia characterised by the release of large sized immature red blood cells into the circulation.
· Sprue and symptoms like glossitis and gastro intestinal disturbances have also been reported.
· Macrocytic anemia of pregnancy responds to treatment with folic acid.