Folic acid is part of the water-soluble vitamin B complex and functions as a coenzyme, together with vitamins Bj2 and C, in the breakdown and utilization of proteins. Folic acid performs its basic role as a carbon carrier in the formation of heme, the iron-containing protein found in hemoglobin, necessary for the formation of red blood cells. It also is needed for the formation of nucleic acid, which is essential for the processes of growth and reproduction of all body cells.
Folic acid is necessary for proper brain function, being concentrated in the spinal and extracellular fluids. It is essential for mental and emotional health. It also increases the appetite and stimulates the production of hydrochloric acid, which helps prevent intestinal parasites and food poisoning. In addition, it aids in performance of the liver. Folic acid is easily destroyed by high temperature, exposure to light, and being left at room temperature for long periods of time.
In surveys conducted, folic acid was shown to be one of the nutrients most often deficient in our diets. The best sources of folic acid are green leafy vegetables, liver, and brewer's yeast.
Folic acid is absorbed in the gastrointestinal tract by active transport and diffusion and is stored primarily in the liver. Sulfa drugs may interfere with the bacteria in the intestine which manufacture folic acid. Aminoperin and streptomycin destroy folic acid.
Any disease such as sprue, celiac disease, or any illness accompanied by vomiting or diarrhea that interferes with the absorption of food can result in a deficiency. Oral contraceptives interfere with the absorption of folic acid.
The Recommended Dietary Allowance of folic acid is 400 micrograms for adults, 800 micrograms during pregnancy, and 600 micrograms during lactation.
Requirements can vary with individual metabolic rate. Hemolytic anemia and hyperthyroidism need higher quantities. Stress and disease increase the body's need for folic acid, as does the consumption of alcohol. There is no known toxicity of this vitamin, although an excessive intake of folic acid can mask a vitamin B12 deficiency.
Deficiency Effects and Symptoms
Deficiency of folic acid results in poor growth, graying hair, glossitis (tongue inflammation), and gastrointestinal-tract disturbances arising from inadequate dietary intake, impaired absorption, excessive demands by tissues of the body, and metabolic disturbances. Because of the role folic acid plays in the formation of red blood cells, a deficiency could lead to anemia that cannot be corrected by supplementary iron.
A folate deficiency can lead to irritability, forgetful-ness, and mental sluggishness. It can be the cause of lesions at the corners of the mouth called cheiloses. A deficiency has been found in mentally retarded children, the aged, and in people with ailments such as Hodgkin's disease and leukemia where the requirement for folic acid is above normal.
Alcohol, phenobarbital and anticonvulsants can produce a folic acid deficiency. Low serum and cerebrospinal fluid folate levels have been observed in epileptics administered anticonvulsant medication.
In the past few years there have been a number of studies implicating folic acid deficiency as a contributing factor in mental illness. Studies have shown that prolonged folic acid deficiency can cause neurological changes and mental deterioration. Because of their close interrelationship, vitamin B12, in almost every case, should accompany any folic acid therapy.
A need for the vitamin is especially increased during pregnancy. The fetus, meeting its need for rapid growth, easily depletes the mother's reserves. The World Health Organization reports that one-third to one-half of pregnant women are folic acid deficient in the last three months of pregnancy. Almost any interference with the metabolism of folic acid in the fetus encourages deformities such as cleft palate, brain
damage, or slow development and poor learning ability in the child. In addition, deficiency of folic acid may lead to toxemia, premature birth, afterbirth hemorrhaging, and megaloblastic anemia in both mother and child.
Beneficial Effect on Ailments
Folic acid is not limited to treatment of anemia. It is beneficial in treating diarrhea, sprue, dropsy, stomach ulcers, menstrual problems, leg ulcers, and glossitis. Circulation may be improved in patients suffering from atherosclerosis. Folic acid may prevent the graying of hair when used with PABA and pantothenic acid. During pregnancy, folacin-rich foods should be stressed in the diet so that the fetal and maternal needs are met and megaloblastic anemia is prevented.