Folate and Vitamin B12 Function

Abstract

Folate and vitamin B12 are dietary essential vitamins required for human health. Folate functions as a cofactor in the synthesis of nucleotides required for DNA synthesis and in amino acid metabolism including the synthesis of the methyl group of methionine, an amino acid used extensively in methylation reactions. Vitamin B12 metabolism interacts with folate metabolism as it is also a cofactor in synthesis of methionine and the catabolism of other amino acids. The classic symptom of both folate and vitamin B12 deficiency is an identical megoloblastic (large cell) anemia, which is a reflection of defective DNA synthesis. Vitamin B12 deficiency can also cause subacute combined disease, a severe demyelination condition. The finding that periconceptional folate supplementation greatly reduced the incidence of birth defects such as spina bifida in humans has led to fortification of the food supply with folic acid in the United States and over 50 other countries.