Occurrence of Folic acid Compounds
Green leafy vegetables and yeast are good sources. Many microorganisms contain appreciable quantities and may supply man and other animals, through intestinal synthesis, with significant amounts. Liver contains more folic acid activity than other materials studied (around 300 /lg per 100 g). Grains and green leafy vegetables vary from 20 or 30 up to 100 /lg per 100 g. Some of the activity may be free in natural products but a larger portion is in a bound form.
Requirements of Folic Acid
A study offood content showed, in adequate high-cost and low-cost diets, 0.193 and 0.157 mg total folic acid, respectively, of which 0.065 mg was free. In deficient diets 0.047 total and .015 mg free folic acid were found. These dietary levels should meet the requirement for the vitamin, with some increase during pregnancy through increased amounts of food rich in biic acid. The actual amounts required are not known. As little as 0.025 mg of crystalline folic acid daily was found to initiate a hematological response in sprue. A daily intake of 0.05 mg prevents a decrease in serum folic acid, but 0.025 mg daily does not. Reviews on folic acid are listed.
