Folic Acid - Benefits, Deficiency Symptoms And Food Sources

Alternative name : Vitamin B9, Folate, Folacin and Pteroylglutamic acid

Folic acid, also known as folacin or folate is a water-soluble B-complex vitamin. It was described by several researchers during the 1930s and 1940s as a factor required by some animals. Folic acid was named in 1941 by Mitchell; its name is derived from the Latin word for leaf, 'folium' due to its widespread prevalence in green leafy vegetables and its acidic nature.

The chemical name of folic acid is pteryolglutamic acid. It is composed of three acids - Pteroic Acid, Para-aminobenzoic Acid (PABA) and Glutamic Acid. About 25% of the folacin in foods is in the free form and is readily absorbed. The rest is conjugated with additional glutamic acid groups. This needs to be digested before absorption. The bioavailability of folates from diet is only about 50%.

Folacin is stored principally in the liver. The coenzyme form of folic acid is Tetrahydrofolic Acid (THF). Vitamin C prevents the oxidation of this active form of folic acid, which functions as a coenzyme in several reactions.

Folic acid is sparingly soluble in water and stable in alkalis. It is easily oxidised in acidic, medium and is sensitive to light. No adverse effects of high oral doses of folate have been reported.

Functions and benefits of folic acid

Folates function as coenzymes that link up with and transfer single-carbon units in a variety of metabolic reactions involving nucleic acids and amino acids. A number of key compounds are formed as a result of this transfer. One of these is THF. Together with vitamin B12, THF is essential for the synthesis of nitrogen-containing compounds, purines and pyrimidines, which are the building blocks of DNA and RNA. DNA and RNA are the information molecules of our body, which carry all the genetic information. Another important function of folic acid is in the synthesis of haeme, the iron-containing part of haemoglobin. Folic acid is thus necessary for the synthesis and maturation of Red Blood Cells (RBCs). Because of its role in DNA synthesis and RBC formation, folate requirements increase during periods of accelerated growth such as pregnancy, lactation and adolescence.

Folate enzymes are also required for the synthesis of several important amino acids. It is required for the synthesis of amino acid serine and for the conversion of homocysteine to amino acid methionine. Folate deficiency can result in decreased synthesis of methionine and increased levels of homocysteine. The latter is a risk factor for heart disease.

Because folacin is required for protein synthesis, folacin inhibitors have been successfully used in the chemotherapy of various types of cancer.

In many of its functions, folic acid is associated with vitamin B12. Vitamin B12 also makes available the active form of the folate coenzymes to participate in purine and pyrimidine synthesis and other functions.

Folic acid is the single most important nutrient for a pregnant woman and her developing foetus. In fact, eating fresh fruits and vegetables rich in folate, from conception until the due date, is the best policy a woman can adopt to ensure that her pregnancy will be a happy and a healthy one. Folic acid also improves lactation.

Daily allowances of folic acid

The minimum Recommended Dosage Allowance of folic acid

• Men - 200 mcg.
• Women - 180 mcg.
• Women of childbearing age - 400 mcg.

Rich sources of folic acid

Fresh green vegetables, such as spinach and broccoli contain folic acid. It is also found in fruit, starchy vegetables, beans, whole grains and liver.

Deficiency symptoms of folic acid

A sore, red tongue is one sign of folic acid deficiency. Other possible signs include anemia, apathy, digestive disturbances, fatigue, graying hair, growth impairment, insomnia, labored breathing, memory problems, paranoia, weakness, and birth defects in one's offspring. Folic acid deficiency may be caused by inadequate consumption of fresh fruits and vegetables; consumption of only cooked or micro waved vegetables (cooking destroys folate); and malabsorption problems.