Folic Acid

General Info

Absorbtion
Folic acid absorption primarily takes place in the first part of the small intestine by two separate mechanisms, they are as follows: an active transport, which requires a folatebinding protein (FBP), and passive diffusion, which accounts for 20 to 30 percent of folate absorption.
Dietary Origins
Folic acid is found in a large variety of foods. The best sources include brewer's yeast, dark green leafy vegetables, eggs, and liver. Other good sources are beets, broccoli, brussels sprouts, orange juice, cabbage, cauliflower, cantaloupe, kidney and lima beans, wheat germ, and whole grain cereals and breads. The "friendly" intestinal bacteria also form folic acid.

Overview
Folic acid is a member of the water-soluble B vitamin group. Referred to as folate, folinic acid, and vitamin B9. The word “folate” is derived from green leafy vegetables. Folic acid plays a major role in cell division, as it is involved in both DNA and RNA processes. This explains the importance of folic acid in fetal development, as well as in possibly preventing some age-related diseases.
Toxicities & Precautions

General
There are no known toxicities or precautions associated with folic acid. Large doses of folic acid can conceal a vitamin B12 deficiency, which if left undetected, could result in irreversible nerve damage.
Functions in the Body

DNA and RNA:
Folic acid is necessary for the synthesis of both DNA and RNA. Hence, it is essential for proper cellular division and the transportation of the genetic code to all newly formed cells.
Pregnancy:
It is necessary for decreased occurrence of neural tube defects during pregnancy. The neural tube develops into the brain, spinal cord, nerves, and nerve tissue.
Protein and Amino Acid:
Involved in the synthesis of proteins and various amino acids.
Red Blood Cells:
Also it is essential for the development of red blood cells.
Symptoms & Causes of Deficiency

Folic acid deficiency interrupts DNA metabolism, which causes abnormal cellular development. This is shown especially in cells with the most rapid rates of turnover, which includes epithelial cells of the stomach, intestine, leukocytes, red blood cells, uterine cervix, and vagina. Folic acid is one of the most common vitamin deficiencies. Folic acid is essential during pregnancy. Destruction of folic acid occurs during food processing, heat, light, and oxygen may easily destroy it. Anemia, abnormally large red blood cells, is a result of a folic acid or vitamin B12 deficiency. Symptoms of folic acid deficiency include birth defects, cervical dysplasia, and elevated homocysteine, fatigue, headache, hair loss, and insomnia.

The following drugs can cause folic acid depletion: oral contraceptives, triamterene, a diuretic drug, anticonvulsants, drugs used to treats seizures, H-2 receptor antagonists, drugs that reduce stomach acids, trimethoprim, used to treat urinary tract infections, cholestyramine, used to lower serum cholesterol levels, anti-inflammatory drugs, methotrexate, an antimetabolite drug, aspirin, antacids, and alcohol.