Dosage Oral: RDI: 400 mcg/day; ODA: 400-1000 mcg/day

Reported Uses

Alcoholism (Lindenbaum, 1980)
Alzheimer's disease (Kruman, 2002)
Anemia (Swain, 1997)
Atherosclerosis (Schnyder, 2001; Swain, 1997)
Cancer (preventive; colon and breast) (Freudenheim, 1991; Zhang, 1999)
Cervical dysplasia (Buckley, 1992)
Coronary heart disease (risk reduction) (Chambers, 2000; Rimm, 1998)
Coronary restenosis (rate reduction by decreasing plasma homocysteine levels) (Schnyder, 2001)
Crohn's disease (Rath, 1998)
Dementia and Alzheimer's disease (risk reduction) (Seshadri, 2002)
Depression (Godfrey, 1990)
Gingivitis (Pack, 1984)
Homocysteine (reduction) (Chambers, 2000; Hanley, 2004; Jacques, 1999; Kruman, 2002; McKinley, 2001; Toole, 2004; Woodside, 1999)
Osteoporosis (Brattstrom, 1985)
Pregnancy (prevention of birth defects) and lactation (Steegers-Theunissen, 1995)
Schizophrenia (risk reduction, by decreasing homocysteine levels) (Susser, 1998)
Ulcer, aphthous (pharmacologic activity)

Summary Folic acid is a water-soluble B vitamin which serves as a cofactor in many enzymatic reactions related to growth and development, neuronal function, and blood cell production. The dietary intakes of many individuals, particularly alcoholics, are known to be less than the RDI. Folic acid is an important nutrient which may be useful in the prevention of atherosclerosis and neural tube birth defects. In addition, it has been used for anemias, depression, and osteoporosis.

Pharmacology In humans, folic acid is converted to its biologically active form, tetrahydrofolic acid (THFA). Folic acid participates in methylation reactions, such as the conversion of homocysteine to methionine. Elevated homocysteine is a risk factor for accelerated atherosclerosis in some individuals. Folic acid is also required for the synthesis of amino acids, the precursors to protein synthesis. In addition, folate is necessary for the synthesis of both DNA and RNA. For this reason, it is essential for cellular growth and division. It is required for the formation of all new cells, and is particularly important in the production of red blood cells, hair, and skin. In addition, it is required for proper functioning of the neuronal cells. Folic acid is necessary for closure of the neural tube during pregnancy.

Toxicities, Warnings, and Interactions Large doses can mask symptoms of vitamin B12 deficiency.

Symptoms of Deficiency Anemia, heartburn, fatigue, diarrhea, constipation, depression, frequent infections, mental confusion.

Drug/Nutrient Interactions: Drugs which can cause depletion of folic acid: Oral contraceptives, potassium-sparing diuretics (triamterene), bile acid sequestrants, anticonvulsants (barbiturates, phenytoin, carbamazepine, primidone, valproate), corticosteroids (prednisone), NSAIDs, sulfasalazine, methotrexate, trimethoprim-containing antibiotics (co-trimoxazole), H2-receptor antagonists, aspirin, antacids, alcohol, cycloserine, pyrimethamine, antibiotics, biguanides, salsalate High doses of folic acid may alter the metabolism of phenytoin, phenobarbital, or primidone; may decrease the efficacy of methotrexate (in cancer therapy) and pyrimethamine; cholestyramine, and colestipol may decrease absorption