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 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. When choosing a supplement, look for third-party 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.
Health Benefits
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:
- Alcoholism
- Pregnancy
- Malabsorption disorders
- Methylenetetrahydrofolate reductase (MTHFR) polymorphism
Do I Have a Folate Deficiency?
A sign of folate deficiency is megaloblastic anemia, which includes symptoms like:
- Weakness
- Fatigue
- Difficulty concentrating
- Irritability
- Headache
- Heart palpitations
- Shortness of breath
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.
Since the Food and Drug Administration (FDA) mandated folate fortification of some grain foods in the late 1990s, the overall rate of NTDs in the U.S. has declined by 28%. However, racial and ethnic disparities in NTD rates still need to be addressed.
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:
- Autism spectrum disorder (ASD): Some research suggests that taking folic acid or multivitamin supplements during pregnancy can reduce the risk of ASD. However, study results are mixed, and no definitive evidence supports this claim.
- Cancer prevention: Studies have looked at the association between folic acid intake and risk for certain cancers with unclear results. The U.S. Department of Health and Human Services National Toxicology Program has identified this as an area that warrants further research.
- Cognitive function and/or decline: It’s known that folic acid helps reduce homocysteine levels. High levels of homocysteine have been linked to cognitive problems and dementia. This does not necessarily mean that folic acid intake will be associated with improved cognition, but studies are trying to find out. Most studies have not indicated any correlation between folic acid supplements and cognitive function, but more research is necessary.
- Depression: Some studies suggest a link between low folate levels and depression. However, not all studies show the same.
How Much Do You Need?
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:
- 1 mcg of food folate
- 0.6 mcg of folic acid from food or supplements when consumed with food
- 0.5 mcg of folic acid from supplements taken on an empty stomach
| RDAs for Folate (micrograms of Dietary Folate Equivalents) | ||||
|---|---|---|---|---|
| Age | Male | Female | Pregnancy | Lactation |
| Birth-6 months | 65 | 65 | ||
| 7-12 months | 80 | 80 | ||
| 1-3 years | 150 | 150 | ||
| 4-8 years | 200 | 200 | ||
| 9-13 years | 300 | 300 | ||
| 14-18 years | 400 | 400 | 600 | 500 |
| 19+ years | 400 | 400 | 600 | 500 |
Who Should Take Folic Acid Supplements?
The following people should discuss folic acid supplementation with their healthcare providers:
Sources
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:
- Spinach
- Asparagus
- Broccoli
- Brussels sprouts
- Beans, particularly kidney beans
- Nuts, particularly peanuts
- Peas, particularly black-eyed peas
- Eggs
- Dairy
- Meat
- Seafood
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:
- Mask a vitamin B12 deficiency. This could have long-term consequences because the neurological complications of vitamin B12 deficiency can become irreversible if not caught early.
- Progress the growth of certain cancers, though studies of this are preliminary.
- Slow cognitive development: Excessive intake (greater than 1,000 mcg daily before conception) may lead to lower test scores on cognitive development in children (compared to those taking 400 mcg folate.
- Negatively affect immune function, but studies of this are preliminary.
- Be associated with cognitive impairment in older adults.
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:
- Methotrexate: Methotrexate can treat certain cancers and autoimmune diseases. Folic acid supplements may reduce the effectiveness of this medication.
- Dilantin (phenytoin), valproate, and Tegretol (carbamazepine): These medications treat epilepsy and some psychiatric conditions. They may also reduce folate levels. Conversely, folic acid supplements may reduce levels of these drugs in the body.
- Sulfasalazine: Sulfasalazine can treat ulcerative colitis. It interferes with the absorption of folate.
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.
Women who are planning to become pregnant or could become pregnant should take folic acid supplements as recommended by their healthcare provider. Other uses of folic acid supplementation require further study.
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.
