Occurrence of folic acid
Folic acid is an active principle widely occurring in the animal and vegetable kingdom. Richest sources are liver, dark green leafy vegetables, beans, wheat germ and yeast. Most dietary folates exist in the polyglutamate form which is converted in the small intestine to the monoglutamate form before absorption in the blood stream. Enzymes present in the liver catalyses the liberation of folic acid from these compounds. Bacteria, yeasts and molds contain abundant amounts of folic acid or its component 4-aminobenzoic acid; both these compounds stimulate their growth.