The Consumer Guide to Folic Acid
What Is It?Why Is It Essential?
Benefits and Uses
Daily Requirement
Deficiency Risk Factors
Optimal Intake
Food Sources
Recent Findings
Safety
What Type of Folic Acid Supplements Are Available?
References
Browse Our Wide Selection of Folic Acid Supplements
What is it? Also known as folate and folacin, folic acid is a water-soluble B complex vitamin discovered in 1931 that helps produce red blood cells, synthesize nucleic acids including DNA, and maintain proper nervous system function.
Why is it essential? DNA allows cells—including cells in the fetus when a woman is pregnant—to replicate normally. Adequate intake of folic acid early in pregnancy is important for preventing most neural tube birth defects as well as some birth defects of the arms, legs, and heart. It may also protect against cleft palate and cleft lip formation. Folic acid is needed to make S-adenosyl methionine, which affects (and may improve) mood. Folic acid is also needed to balance blood levels of the amino acid homocysteine. Excess homocysteine dramatically increases the risk of heart disease and may be linked to osteoporosis and strokes. Folic acid also works with vitamin B12 to synthesize proteins.
Benefits and uses: Although its most dramatic use is in preventing heart disease and certain types of birth defects, folic acid can also play a role in helping to prevent or treat a number of other conditions, including Crohn’s disease, depression, diarrhea, gum disease, gout, high cholesterol, osteoporosis, vitiligo, and ulcerative colitis. Folic acid is necessary for proper immune system function and recovery from illness and injury. People who don’t get enough folic acid often suffer from weakness, anxiety, insomnia, and other ailments.
Daily requirement: The new RDI for folate ranges from 400 to 600 mcg for adults.
Deficiency risk factors: Most people do not consume the recommended amount of folic acid. Recently, scientists have found that many people with heart disease have elevated blood levels of homocysteine, which is often controllable with folic acid. This suggests that many people in Western societies have a mild folic acid deficiency. In fact, increasing folic acid intake could potentially prevent an estimated 13,500 deaths from cardiovascular diseases each year. Folic acid deficiency is also common in alcoholics, people living at poverty level, those with malabsorption disorders, and users of certain drugs including anticonvulsants, oral contraceptives, and corticosteroids. Proteolytic enzymes and antacids inhibit folic acid absorption; people taking either should supplement with folic acid.
Optimal intake: An optimal daily level for supplementation is 400 to 800 mcg. All women who are or who could become pregnant should take at least that amount every day to reduce the risk of birth defects.
Food sources: Folic acid occurs in both in animal and plant foods, with dark green leafy vegetables like spinach, chard, and kale being especially rich sources. (Think "foliage," from the same Latin root as folic.) Whole, fresh foods typically have much higher levels than processed foods. Kidney beans, beets, wheat germ, and meat are good sources of folic acid. Other sources include brewer’s yeast, fruits such as bananas and cantaloupes, lentils, and asparagus. Breakfast cereals are often fortified with folic acid.
Recent findings: A flurry of recent studies have confirmed important aspects of the folic acid/homocysteine connection to heart disease, including one that assessed the long-term effects of small increases in dietary folic acid and another that concluded benefits were most likely from taking folic acid in amounts in excess of current recommended dietary allowances.
Safety: Folic acid is remarkably safe, at least up to perhaps 15 to 20 mg per day (at which point it may cause adverse mental effects and other symptoms of toxicity). The main danger from taking 1,000 mcg of folic acid per day or more is an indirect one: if you happen to be deficient in vitamin B12, the folic acid can mask some of the deficiency symptoms and possibly delay proper diagnosis, potentially causing permanent harm. This problem is rare, and should not happen with doctors knowledgeable in this area using correct testing procedures.
What type of folic acid supplements are available? Most products are capsules and tablets ranging in potency from 400 to 800 mcg. Some include added B12.
- Daly, L.E., et al., "Folate levels and neural tube defects," JAMA (1995), 274:1698–1702
- Russel, R.M., "A minimum of 13,500 deaths annually from coronary artery disease could be prevented by increasing folate intake to reduce homocysteine levels," J Am Med Assoc (1996), 275:1828–89
- Schorah, C.J., et al., "The responsiveness of plasma homocysteine to small increases in dietary folic acid: a primary care study," Eur J Clin Nutr (1998), 52(6):407–11
- Brouwer, D.A., et al., "[Recommended dietary allowance of folic acid is insufficient for optimal homocysteine levels]," Ned Tijdschr Geneeskd (1998), 142(14):782–86
- Butterworth, C.E. Jr., and T. Tamura, "Folic acid safety and toxicity: a brief review," Am J Clin Nutr (1989), 50:353–58
Browse Our Wide Selection of Folic Acid Supplements