Folic Acid Deficiency
Inadequate diet—alcoholism, infancy
Intrinsic intestinal disease
Anticonvulsants, oral contraceptives
Pregnancy, infancy, disseminated cancer, markedly increased hematopoiesis
Folic acid antagonists
Metabolic inhibitors of DNA synthesis and/or folate metabolism, e.g., methotrexate.
the best sources of folate are fresh uncooked vegetables and fruits. Food folates are predominantly in polyglutamate form and must be split into monoglutamates
Phenytoin and a few other drugs inhibit folate absorption, while others, such as methotrexate, inhibit folate metabolism
The principal site of intestinal absorption is the upper third of the small intestine; thus, malabsorptive disorders that affect this level of the gut, such as celiac disease and tropical sprue, can impair folate uptake
conversion from dihydrofolate to tetrahydrofolate by the enzyme dihydrofolate reductase is particularly important.
Tetrahydrofolate acts as an acceptor and donor of one-carbon units in a variety of steps involved in the synthesis of purines and thymidylate, the building blocks of DNA, and its deficiency accounts for the inadequate DNA synthesis
measuring serum and red cell folate
symptoms referable to the alimentary tract are common and often severe. These include sore tongue and cheilosis.