Folic acid is very sensitive and is easily destroyed in a variety of ways, such as by light, heat, any type of cooking, or an acid pH below 4; it can even be lost from foods when they are stored at room temperature for long periods. The potency of this B vitamin is diminished in most food processing and food preparation.

When folic acid is consumed, it is actively transported into the blood from the gastrointestinal tract, where it acts as a coenzyme for a multitude of functions and often is converted to its active form, tetrahydrofolic acid (THFA), in the presence of the niacin coenzyme (NADPH) and vitamin C. In the body, folic acid is found mainly as methyl folate, and vitamin B12 is needed to convert it back to the active THFA. Extra folic acid is stored in the liver, enough for six to nine months of vitamin for body use before deficiency symptoms might develop.

Folic acid deficiency, however, may still be one of the most common vitamin deficiencies. It is more likely to be a problem in the elderly, in alcoholics, in psychiatric patients, in epileptics, in women on birth control pills, and with drug therapy such as the sulfa antibiotics and tetracyclines that deplete folic acid-producing bacteria in the colon. Pregnancy is a time for concern about sufficient folic acid intake (the RDA doubles during pregnancy). Also, those eating the standard American diet that is high in fats, meats, white flour, white sugar, and desserts may develop folic acid deficiency. Eating some fresh or lightly cooked vegetables daily will allow us to maintain normal folate levels.

Folic acid was discovered in 1931 as a "cure" for the anemia of pregnancy. Eating extra yeast also seemed to relieve the symptoms of pernicious anemia, but the neurological symptoms of this disease either were not resolved or appeared later on, confirming some doctors’ feelings that there were two different problems involved. In 1945, folic acid was isolated from spinach; we now know that B12 and folic acid produce two very similar deficiency problems. B12 deficiency may lead to progressive and irreversible neurological damage, whereas a lack of folic acid will not, but taking a lot of folic acid may cover up the B12 anemia and other symptoms until it is too late for effective treatment with vitamin B12. Therefore, vitamin tablets of folic acid with over 400 mcg. have been taken off the market and are available by prescription only. If megaloblastic (enlarged red blood cells) anemia occurs, both folic acid and vitamin B12 levels should be checked to assure proper treatment and follow-up.

Sources: The best source of folic acid is foliage, the green leafy vegetables. These include spinach, kale, beet greens and even beets, chard, asparagus, broccoli, sources are liver and kidney and brewer’s yeast. Starchy vegetables containing some folacin are corn, lima beans, green peas, sweet potatoes, artichokes, okra, and parsnips. Bean sprouts, such as lentil, mung, and soy, are particularly good, as are wheat germ or flakes and soy flour. Whole wheat bread, other natural, whole grain baked goods, and milk also have some folic acid. And many fruits have folic acid, such as oranges, cantaloupe, pineapple, banana, and many berries, including loganberries, boysenberries, and strawberries.