Table of ContentsView AllTable of ContentsFunctions of Folic AcidHealth BenefitsHow Much Do You Need?Who Should Take Folic Acid Supplements?SourcesPrecautionsInteractions
Table of ContentsView All
View All
Table of Contents
Functions of Folic Acid
Health Benefits
How Much Do You Need?
Who Should Take Folic Acid Supplements?
Sources
Precautions
Interactions
Folate is a water-soluble B vitamin. It is also called folic acid, folacin, or vitamin B9. Folic acid is a synthetic form of folate used in supplements or added to foods for fortification, whereas folate is found naturally in foods.
Folate is an essential nutrient that offers many health benefits for the human body. It is necessary for red blood cell development and cell function. Folate becomes very important for fetal development during pregnancy.
Most people get enough folate through their diet. Many fruits and green leafy vegetables are rich in folate. Beans, peanuts, eggs, and some meats are also good sources. Some grains, like breakfast cereals, are enriched with added folic acid.
Folic acid supplements are available for those who need additional folate or can’t enough in their diet.
This article reviews the functions and benefits of folate, who may benefit from supplementation, and how to best do so.
A Word on SupplementsIn the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it regulates prescription drugs. That means some supplement products may not contain what the label says. Whenchoosing a supplement, look for independently tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.
A Word on Supplements
In the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it regulates prescription drugs. That means some supplement products may not contain what the label says. Whenchoosing a supplement, look for independently tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.
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What Are the Functions of Folic Acid?
Folate is involved in several biochemical reactions in the body:
Folic Acid vs Folate: Are They the Same?Folate is an inclusive term that refers to the different forms of vitamin B9, including folic acid. Folate occurs naturally in foods. Folic acid is a synthetic form of folate used in supplements or added to foods for fortification.Folate is not as stable as folic acid. Heat and light can break down folate, so it can be lost during cooking. Therefore, manufacturers use folic acid to fortify foods like breads, grains, and cereals.Folic acid is easily absorbed. The bioavailability (amount of a substance absorbed) of folic acid is about 85% when taken with food and 100% when taken on an empty stomach.Both folate and folic acid may interact with prescribed medications.
Folic Acid vs Folate: Are They the Same?
Folate is an inclusive term that refers to the different forms of vitamin B9, including folic acid. Folate occurs naturally in foods. Folic acid is a synthetic form of folate used in supplements or added to foods for fortification.Folate is not as stable as folic acid. Heat and light can break down folate, so it can be lost during cooking. Therefore, manufacturers use folic acid to fortify foods like breads, grains, and cereals.Folic acid is easily absorbed. The bioavailability (amount of a substance absorbed) of folic acid is about 85% when taken with food and 100% when taken on an empty stomach.Both folate and folic acid may interact with prescribed medications.
Folate is an inclusive term that refers to the different forms of vitamin B9, including folic acid. Folate occurs naturally in foods. Folic acid is a synthetic form of folate used in supplements or added to foods for fortification.
Folate is not as stable as folic acid. Heat and light can break down folate, so it can be lost during cooking. Therefore, manufacturers use folic acid to fortify foods like breads, grains, and cereals.
Folic acid is easily absorbed. The bioavailability (amount of a substance absorbed) of folic acid is about 85% when taken with food and 100% when taken on an empty stomach.
Both folate and folic acid may interact with prescribed medications.
Folic acid supplementation can treat a folic acid deficiency and healthcare providers most often recommend it during pregnancy to prevent certain birth defects.
Treats Folate Deficiency
Supplementing folic acid for a folate deficiency is recommended. However, an isolated folate deficiency is rare. Most people who may be deficient in folate will also be deficient in other nutrients. You should discuss any nutrient deficiencies with your primary healthcare provider.
Conditions that increase your risk of folate deficiency include:
Do I Have a Folate Deficiency?A sign of folate deficiency is megaloblastic anemia, which includes symptoms like:WeaknessFatigueDifficulty concentratingIrritabilityHeadacheHeart palpitationsShortness of breathYou may also develop mouth ulcers or soreness, changes in skin, hair, or fingernail pigmentation, stomach-related issues, and high blood levels of homocysteine.
Do I Have a Folate Deficiency?
A sign of folate deficiency is megaloblastic anemia, which includes symptoms like:WeaknessFatigueDifficulty concentratingIrritabilityHeadacheHeart palpitationsShortness of breathYou may also develop mouth ulcers or soreness, changes in skin, hair, or fingernail pigmentation, stomach-related issues, and high blood levels of homocysteine.
A sign of folate deficiency is megaloblastic anemia, which includes symptoms like:
You may also develop mouth ulcers or soreness, changes in skin, hair, or fingernail pigmentation, stomach-related issues, and high blood levels of homocysteine.
Prevents Neural Tube Defects
NTDs are the most common congenital malformation of the central nervous system. They affect the spine, skull, or brain. Research has shown adequate folate intake before conception and during early pregnancy prevents NTDs.
The United States (U.S.) Preventive Services Task Force recommends that all people who are capable of or planning to become pregnant take a daily supplement containing 400 to 800 micrograms (mcg) of folic acid starting at least one month before conception and continuing through the first two to three months of pregnancy.
Reduces Homocysteine Levels
Elevated homocysteine levels are associated with increased heart disease risk. Because the body needs folic acid for homocysteine metabolism, researchers have hypothesized that supplementation could help reduce homocysteine levels.
Research has generally found that supplementing folic acid does reduce homocysteine levels. However, supplementation doesn’t necessarily reduce the risk of heart disease, heart attacks, or death.However, supplementation does appear to reduce the risk of stroke.
Other Areas of Research
Other areas of folic acid supplementation research are inconclusive. More research is still necessary to determine the effects of folic acid supplementation for:
The Food and Nutrition Board has set Recommended Dietary Allowances (RDAs) for folic acid intake.
The RDAs are set as dietary folate equivalents (DFE) because the bioavailability of folic acid and folate in food differs. One DFE equals:
The following people should discussfolate supplementswith their healthcare providers:
Folate is naturally available in many foods, including vegetables, fruits, beans, and nuts. As a supplement, folic acid is found in several blended supplement regimens or as a single nutrient.
Food Sources
Food sources of folate include:
In the late 1990s, the U.S. and Canadian governments began requiring manufacturers to add folic acid to enriched bread, cereals, flour, pasta, and other grain products. Adding 140 mcg per 100 grams enriched grain product increased folate intake in the general population and reduced the risk of NTD. Therefore, these enriched products are also great sources of folate.
Supplements
Folic acid is available in supplements in the following ways:
Common doses of folic acid in supplements range from 400 to 800 mcg for adults and 200 to 400 mcg for children. The bioavailability of folic acid is about 85% when taken with food and 100% when taken on an empty stomach.
Precautions With Supplementation
Folic acid supplements are generally safe, but a few possible areas of concern require further study. Supplemental folic acid may:
The Food and Nutrition Board has set upper limits for folic acid (but not folate from foods). The upper limit is set at 1,000 mcg for adults. Amounts are lower for children.
Folic acid supplements can also interact with prescription medications. Make sure to consult your provider before starting supplementation.
Do Folic Acid Supplements Interact With Any Drugs?
Talk to your healthcare provider before adding supplements to your regimen. Occasionally, supplements will interact with prescribed medications. Your provider can help you determine whether a certain supplement will benefit you or not.
Folic acid supplements can interact with the following medications:
Summary
Folate is an essential nutrient that most people can enough through their diet. It has many health benefits for the body, including its role in the development of red blood cells and preventing NTDs in pregnancy.
If you’re unsure whether you are getting enough folic acid, consult your healthcare provider or a registered dietitian nutritionist (RDN). They can help you determine whether supplementation is necessary for you.
14 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute of Health Office of Dietary Supplements.Folate.Bibbins-Domingo K, Grossman DC, Curry SJ, et al.Folic acid supplementation for the prevention of neural tube defects: US Preventive Services Task Force recommendation statement.JAMA. 2017;317(2):183-189. doi:10.1001/jama.2016.19438Huang T, Chen Y, Yang B, et al.Meta-analysis of B vitamin supplementation on plasma homocysteine, cardiovascular and all-cause mortality.Clin Nutr. 2012;31(4):448-454. doi:10.1016/j.clnu.2011.01.003Martí-Carvajal AJ, Solà I, Lathyris D, Dayer M.Homocysteine-lowering interventions for preventing cardiovascular events.Cochrane Database Syst Rev. 2017;8(8):CD006612. Published 2017 Aug 17. doi:10.1002/14651858.CD006612.pub5Virk J, Liew Z, Olsen J, et al.Preconceptional and prenatal supplementary folic acid and multivitamin intake and autism spectrum disorders.Autism. 2016;20(6):710-718. doi:10.1177/1362361315604076Levine SZ, Kodesh A, Viktorin A, et al.Association of maternal use of folic acid and multivitamin supplements in the periods before and during pregnancy with the risk of autism spectrum disorder in offspring.JAMA Psychiatry. 2018;75(2):176-184. doi: 10.1001/jamapsychiatry.2017.4050National Toxicology Program.NTP monograph: identifying research needs for assessing safe use of high intakes of folic acid.Smith AD, Refsum H.Homocysteine, B vitamins, and cognitive impairment.Annu Rev Nutr. 2016;36:211-239. doi:10.1146/annurev-nutr-071715-050947Clarke R, Bennett D, Parish S, et al.Effects of homocysteine lowering with B vitamins on cognitive aging: meta-analysis of 11 trials with cognitive data on 22,000 individuals.Am J Clin Nutr. 2014;100(2):657-666. doi:10.3945/ajcn.113.076349Sarris J, Murphy J, Mischoulon D, et al.Adjunctive nutraceuticals for depression: a systematic review and meta-analyses.Am J Psychiatry. 2016;173(6):575-587. doi:10.1176/appi.ajp.2016.15091228Bedson E, Bell D, Carr D, et al.Folate augmentation of treatment - evaluation for depression (FolATED): randomised trial and economic evaluation.Health Technol Assess. 2014;18(48):vii-viii, 1-159. doi:10.3310/hta18480Valera-Gran D, Navarrete-Muñoz EM, Garcia de la Hera M, et al.Effect of maternal high dosages of folic acid supplements on neurocognitive development in children at 4-5 y of age: the prospective birth cohort Infancia y Medio Ambiente (INMA) study.Am J Clin Nutr. 2017;106(3):878-887. doi:10.3945/ajcn.117.152769Troen AM, Mitchell B, Sorensen B, et al.Unmetabolized folic acid in plasma is associated with reduced natural killer cell cytotoxicity among postmenopausal women.J Nutr. 2006;136(1):189-194. doi:10.1093/jn/136.1.189Morris MS, Jacques PF, Rosenberg IH, Selhub J.Circulating unmetabolized folic acid and 5-methyltetrahydrofolate in relation to anemia, macrocytosis, and cognitive test performance in American seniors[published correction appears in Am J Clin Nutr. 2010 Oct;92(4):1002].Am J Clin Nutr. 2010;91(6):1733-1744. doi:10.3945/ajcn.2009.28671
14 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute of Health Office of Dietary Supplements.Folate.Bibbins-Domingo K, Grossman DC, Curry SJ, et al.Folic acid supplementation for the prevention of neural tube defects: US Preventive Services Task Force recommendation statement.JAMA. 2017;317(2):183-189. doi:10.1001/jama.2016.19438Huang T, Chen Y, Yang B, et al.Meta-analysis of B vitamin supplementation on plasma homocysteine, cardiovascular and all-cause mortality.Clin Nutr. 2012;31(4):448-454. doi:10.1016/j.clnu.2011.01.003Martí-Carvajal AJ, Solà I, Lathyris D, Dayer M.Homocysteine-lowering interventions for preventing cardiovascular events.Cochrane Database Syst Rev. 2017;8(8):CD006612. Published 2017 Aug 17. doi:10.1002/14651858.CD006612.pub5Virk J, Liew Z, Olsen J, et al.Preconceptional and prenatal supplementary folic acid and multivitamin intake and autism spectrum disorders.Autism. 2016;20(6):710-718. doi:10.1177/1362361315604076Levine SZ, Kodesh A, Viktorin A, et al.Association of maternal use of folic acid and multivitamin supplements in the periods before and during pregnancy with the risk of autism spectrum disorder in offspring.JAMA Psychiatry. 2018;75(2):176-184. doi: 10.1001/jamapsychiatry.2017.4050National Toxicology Program.NTP monograph: identifying research needs for assessing safe use of high intakes of folic acid.Smith AD, Refsum H.Homocysteine, B vitamins, and cognitive impairment.Annu Rev Nutr. 2016;36:211-239. doi:10.1146/annurev-nutr-071715-050947Clarke R, Bennett D, Parish S, et al.Effects of homocysteine lowering with B vitamins on cognitive aging: meta-analysis of 11 trials with cognitive data on 22,000 individuals.Am J Clin Nutr. 2014;100(2):657-666. doi:10.3945/ajcn.113.076349Sarris J, Murphy J, Mischoulon D, et al.Adjunctive nutraceuticals for depression: a systematic review and meta-analyses.Am J Psychiatry. 2016;173(6):575-587. doi:10.1176/appi.ajp.2016.15091228Bedson E, Bell D, Carr D, et al.Folate augmentation of treatment - evaluation for depression (FolATED): randomised trial and economic evaluation.Health Technol Assess. 2014;18(48):vii-viii, 1-159. doi:10.3310/hta18480Valera-Gran D, Navarrete-Muñoz EM, Garcia de la Hera M, et al.Effect of maternal high dosages of folic acid supplements on neurocognitive development in children at 4-5 y of age: the prospective birth cohort Infancia y Medio Ambiente (INMA) study.Am J Clin Nutr. 2017;106(3):878-887. doi:10.3945/ajcn.117.152769Troen AM, Mitchell B, Sorensen B, et al.Unmetabolized folic acid in plasma is associated with reduced natural killer cell cytotoxicity among postmenopausal women.J Nutr. 2006;136(1):189-194. doi:10.1093/jn/136.1.189Morris MS, Jacques PF, Rosenberg IH, Selhub J.Circulating unmetabolized folic acid and 5-methyltetrahydrofolate in relation to anemia, macrocytosis, and cognitive test performance in American seniors[published correction appears in Am J Clin Nutr. 2010 Oct;92(4):1002].Am J Clin Nutr. 2010;91(6):1733-1744. doi:10.3945/ajcn.2009.28671
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Institute of Health Office of Dietary Supplements.Folate.Bibbins-Domingo K, Grossman DC, Curry SJ, et al.Folic acid supplementation for the prevention of neural tube defects: US Preventive Services Task Force recommendation statement.JAMA. 2017;317(2):183-189. doi:10.1001/jama.2016.19438Huang T, Chen Y, Yang B, et al.Meta-analysis of B vitamin supplementation on plasma homocysteine, cardiovascular and all-cause mortality.Clin Nutr. 2012;31(4):448-454. doi:10.1016/j.clnu.2011.01.003Martí-Carvajal AJ, Solà I, Lathyris D, Dayer M.Homocysteine-lowering interventions for preventing cardiovascular events.Cochrane Database Syst Rev. 2017;8(8):CD006612. Published 2017 Aug 17. doi:10.1002/14651858.CD006612.pub5Virk J, Liew Z, Olsen J, et al.Preconceptional and prenatal supplementary folic acid and multivitamin intake and autism spectrum disorders.Autism. 2016;20(6):710-718. doi:10.1177/1362361315604076Levine SZ, Kodesh A, Viktorin A, et al.Association of maternal use of folic acid and multivitamin supplements in the periods before and during pregnancy with the risk of autism spectrum disorder in offspring.JAMA Psychiatry. 2018;75(2):176-184. doi: 10.1001/jamapsychiatry.2017.4050National Toxicology Program.NTP monograph: identifying research needs for assessing safe use of high intakes of folic acid.Smith AD, Refsum H.Homocysteine, B vitamins, and cognitive impairment.Annu Rev Nutr. 2016;36:211-239. doi:10.1146/annurev-nutr-071715-050947Clarke R, Bennett D, Parish S, et al.Effects of homocysteine lowering with B vitamins on cognitive aging: meta-analysis of 11 trials with cognitive data on 22,000 individuals.Am J Clin Nutr. 2014;100(2):657-666. doi:10.3945/ajcn.113.076349Sarris J, Murphy J, Mischoulon D, et al.Adjunctive nutraceuticals for depression: a systematic review and meta-analyses.Am J Psychiatry. 2016;173(6):575-587. doi:10.1176/appi.ajp.2016.15091228Bedson E, Bell D, Carr D, et al.Folate augmentation of treatment - evaluation for depression (FolATED): randomised trial and economic evaluation.Health Technol Assess. 2014;18(48):vii-viii, 1-159. doi:10.3310/hta18480Valera-Gran D, Navarrete-Muñoz EM, Garcia de la Hera M, et al.Effect of maternal high dosages of folic acid supplements on neurocognitive development in children at 4-5 y of age: the prospective birth cohort Infancia y Medio Ambiente (INMA) study.Am J Clin Nutr. 2017;106(3):878-887. doi:10.3945/ajcn.117.152769Troen AM, Mitchell B, Sorensen B, et al.Unmetabolized folic acid in plasma is associated with reduced natural killer cell cytotoxicity among postmenopausal women.J Nutr. 2006;136(1):189-194. doi:10.1093/jn/136.1.189Morris MS, Jacques PF, Rosenberg IH, Selhub J.Circulating unmetabolized folic acid and 5-methyltetrahydrofolate in relation to anemia, macrocytosis, and cognitive test performance in American seniors[published correction appears in Am J Clin Nutr. 2010 Oct;92(4):1002].Am J Clin Nutr. 2010;91(6):1733-1744. doi:10.3945/ajcn.2009.28671
National Institute of Health Office of Dietary Supplements.Folate.
Bibbins-Domingo K, Grossman DC, Curry SJ, et al.Folic acid supplementation for the prevention of neural tube defects: US Preventive Services Task Force recommendation statement.JAMA. 2017;317(2):183-189. doi:10.1001/jama.2016.19438
Huang T, Chen Y, Yang B, et al.Meta-analysis of B vitamin supplementation on plasma homocysteine, cardiovascular and all-cause mortality.Clin Nutr. 2012;31(4):448-454. doi:10.1016/j.clnu.2011.01.003
Martí-Carvajal AJ, Solà I, Lathyris D, Dayer M.Homocysteine-lowering interventions for preventing cardiovascular events.Cochrane Database Syst Rev. 2017;8(8):CD006612. Published 2017 Aug 17. doi:10.1002/14651858.CD006612.pub5
Virk J, Liew Z, Olsen J, et al.Preconceptional and prenatal supplementary folic acid and multivitamin intake and autism spectrum disorders.Autism. 2016;20(6):710-718. doi:10.1177/1362361315604076
Levine SZ, Kodesh A, Viktorin A, et al.Association of maternal use of folic acid and multivitamin supplements in the periods before and during pregnancy with the risk of autism spectrum disorder in offspring.JAMA Psychiatry. 2018;75(2):176-184. doi: 10.1001/jamapsychiatry.2017.4050
National Toxicology Program.NTP monograph: identifying research needs for assessing safe use of high intakes of folic acid.
Smith AD, Refsum H.Homocysteine, B vitamins, and cognitive impairment.Annu Rev Nutr. 2016;36:211-239. doi:10.1146/annurev-nutr-071715-050947
Clarke R, Bennett D, Parish S, et al.Effects of homocysteine lowering with B vitamins on cognitive aging: meta-analysis of 11 trials with cognitive data on 22,000 individuals.Am J Clin Nutr. 2014;100(2):657-666. doi:10.3945/ajcn.113.076349
Sarris J, Murphy J, Mischoulon D, et al.Adjunctive nutraceuticals for depression: a systematic review and meta-analyses.Am J Psychiatry. 2016;173(6):575-587. doi:10.1176/appi.ajp.2016.15091228
Bedson E, Bell D, Carr D, et al.Folate augmentation of treatment - evaluation for depression (FolATED): randomised trial and economic evaluation.Health Technol Assess. 2014;18(48):vii-viii, 1-159. doi:10.3310/hta18480
Valera-Gran D, Navarrete-Muñoz EM, Garcia de la Hera M, et al.Effect of maternal high dosages of folic acid supplements on neurocognitive development in children at 4-5 y of age: the prospective birth cohort Infancia y Medio Ambiente (INMA) study.Am J Clin Nutr. 2017;106(3):878-887. doi:10.3945/ajcn.117.152769
Troen AM, Mitchell B, Sorensen B, et al.Unmetabolized folic acid in plasma is associated with reduced natural killer cell cytotoxicity among postmenopausal women.J Nutr. 2006;136(1):189-194. doi:10.1093/jn/136.1.189
Morris MS, Jacques PF, Rosenberg IH, Selhub J.Circulating unmetabolized folic acid and 5-methyltetrahydrofolate in relation to anemia, macrocytosis, and cognitive test performance in American seniors[published correction appears in Am J Clin Nutr. 2010 Oct;92(4):1002].Am J Clin Nutr. 2010;91(6):1733-1744. doi:10.3945/ajcn.2009.28671
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