Folic acid (B9)

Folic acid, also known as folacin and pteroylglutamic acid, is one of the B-complex vitamins that interacts with vitamin B12 for the synthesis of DNA, which is important for all cells in the body. Folic acid, in combination with vitamin B12 and vitamin C, is necessary for the breakdown of proteins and the formation of hemoglobin, a compound in red blood cells that transports oxygen and carbon dioxide. Folic acid is also essential to virtually all biochemical reactions that use a one-carbon transfer and is produced by bacteria in the stomach and intestines.

A deficiency of folic acid causes anemia, poor growth, and irritation of the mouth, all of which are similar to symtoms suffered by those with B12 deficiency. Folic acid is present in nearly all natural foods but can be damaged, or weakened, during cooking. Deficiencies are found mainly in alcoholics, the malnourished, the poor, the elderly and those who are unable to absorb food due to certain diseases (topical sprue, gluten enteropathy).

Folic acid is found in yeast, liver, green vegetables, whole grain cereals and many other foods. The need for folic acid increases during pregnancy, due to high requirements of the vitamin from the fetus. Doctors often suggest a 300 mcg. daily supplement for pregnant women. Many nutritional requirements change during pregnancy, and vitamins are no exception. All of the B vitamins, especially folic acid, should be slightly increased during pregnancy and lactation (breast milk production). The daily intake of folic acid should be increased from 180 mcg. to 400 mcg. during pregnancy and from 180 mcg. to 280 mcg. during lactation.

Mega-doses of folic acid can produce convulsions, interfere with the anticonvulsant medication used by epileptics, and disrupt zinc absorption.