Birth defects can be challenging and deadly, being the leading cause of infant mortality. One in five infant deaths is attributed to birth defects. Folate, a term for naturally occurring B-vitamins, also known as B9, plays a crucial role in preventing these defects. Daily consumption of 400 micrograms of folic acid is recommended for all women of childbearing age. A multivitamin and a diet rich in folate foods are the best ways to ensure adequate folic acid intake.
Understanding Folate and Folic Acid
Folate, also known as vitamin B9, is a water-soluble vitamin with many important functions in the body. It supports healthy cell division and promotes proper fetal growth and development, reducing the risk of birth defects. Vitamin B9 is found naturally in many foods and as folic acid in fortified foods. It’s recommended that healthy adults get at least 400 mcg of folate per day to prevent a deficiency.
The terms folic acid and folate are often used interchangeably. Folate is a B vitamin that occurs naturally in foods like green leafy vegetables, citrus fruits, and beans. Folic acid is a synthetic form of folate found in supplements and added to fortified foods. Folic acid dissolves in water, meaning the body doesn't store it and leftover amounts leave through urine. Folate (folic acid) is necessary for red blood cell production and DNA synthesis, which controls heredity and guides the cell in its daily activities. It also aids tissue growth and cell function, working with vitamin B12 and vitamin C to help the body break down, use, and create new proteins.
Dietary Reference Intakes (DRIs) for Folate
Intake recommendations for folate and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by an expert committee of the Food and Nutrition Board (FNB) at the National Academies of Sciences, Engineering, and Medicine. DRI is the general term for a set of reference values used for planning and assessing nutrient intakes of healthy people. The FNB developed Dietary Folate Equivalents (DFEs) to reflect the higher bioavailability of folic acid than that of food folate. At least 85% of folic acid is estimated to be bioavailable when taken with food, whereas only about 50% of folate naturally present in food is bioavailable.
The Recommended Dietary Allowance (RDA) for vitamins reflects how much of each vitamin most people should get each day and may be used as goals for each person. How much of each vitamin you need depends on your age and sex. Other factors, such as pregnancy and illnesses, are also important.
Read also: Nutrition and Quality of Life in Myelofibrosis
The Food and Nutrition Board of the National Academies of Sciences, Engineering, and Medicine Recommended Intakes for Individuals - Daily Reference Intakes (DRIs) for folate:
- Infants 0 to 6 months: 65 mcg/day*
- Infants 7 to 12 months: 80 mcg/day**For infants from birth to 12 months, the Food and Nutrition Board established an Acceptable Intake (AI) for folate that is equivalent to the mean intake of folate in healthy, breastfed infants in the United States.
Natural Food Sources of Folate
Folate is naturally present in a wide variety of foods. The word folate derives from foliage, which refers to the leafy green veggies that contain some of the highest natural concentrations of the vitamin found in any food.
Here are some healthy foods that are high in folate or folic acid:
Legumes: Legumes, including beans, peas, and lentils, are excellent sources of folate. One cup (177 grams) of cooked kidney beans contains 131 mcg of folate, or about 33% of the Daily Value (DV). Meanwhile, one cup (198 grams) of cooked lentils contains 358 mcg of folate, which is 90% of the DV. Chickpeas, also known as garbanzo beans, contain around 142 mcg per cup. Legumes are also a great source of protein, fiber, and antioxidants, as well as important micronutrients like potassium, magnesium, and iron.
Asparagus: Low in calories, cholesterol and fat, asparagus is a great vegetable for a variety of reasons. Asparagus contains a concentrated amount of many vitamins and minerals, including folate. In fact, a half-cup (90-gram) serving of cooked asparagus contains about 134 mcg of folate, or 34% of the DV. Asparagus is also rich in antioxidants and has been shown to have anti-inflammatory and antibacterial properties. What’s more, it’s an excellent source of heart-healthy fiber, knocking out up to 6% of your daily fiber needs in just one serving.
Read also: Primary Care Weight Loss Options
Eggs: Adding eggs to your diet is a great way to boost your intake of several essential nutrients, including folate. Just one large egg packs 22 mcg of folate, or approximately 6% of the DV. Including even just a few servings of eggs in your diet each week is an easy way to boost your folate intake and help meet your needs. Eggs are also loaded with protein, selenium, riboflavin, and vitamin B12. Furthermore, they’re high in lutein and zeaxanthin, two antioxidants that may help reduce the risk of eye disorders like macular degeneration.
Leafy Green Vegetables: Leafy green vegetables such as spinach, kale, and arugula are low in calories yet bursting with many key vitamins and minerals, including folate. One cup (30 grams) of raw spinach provides 58.2 mcg, or 15% of the DV. Leafy greens are also high in fiber and vitamins K and A and have been associated with a host of health benefits. Studies show that eating more cruciferous vegetables, such as leafy greens, may be associated with reduced inflammation, a lower risk of cancer, and increased weight loss. This cruciferous vegetable is another great source of folate, with about 104 mcg of folate per cup. This versatile salad building block supplies 64 mcg of folate per cup.
Beets: In addition to providing a burst of color to main dishes and desserts alike, beets are rich in many important nutrients. They contain much of the manganese, potassium, and vitamin C that you need throughout the day. They’re also a great source of folate, with a single cup (136 grams) of raw beets containing 148 mcg of folate, or about 37% of the DV. Besides their micronutrient content, beets are high in nitrates, a type of plant compound that has been associated with many health benefits. One older study showed that drinking beetroot juice temporarily lowered systolic blood pressure by 4-5 mmHg in healthy adults.
Citrus Fruits: Besides being delicious and full of flavor, citrus fruits like oranges, grapefruit, lemons, and limes are rich in folate. Just one large orange contains 55 mcg of folate, or about 14% of the DV. Citrus fruits are especially rich in folate. Just one orange holds between 40 and 50 mcg, about ten percent of your daily value. Citrus fruits are also packed with vitamin C, an essential micronutrient that can help boost immunity and aid disease prevention. In fact, observational studies have found that a high intake of citrus fruits may be associated with a lower risk of breast, stomach, and pancreatic cancer.
Brussels Sprouts: This nutritious vegetable belongs to the cruciferous family of vegetables and is closely related to other greens like kale, broccoli, cabbage, and kohlrabi. Brussels sprouts are brimming with many vitamins and minerals and especially high in folate. A half-cup (78-gram) serving of cooked Brussels sprouts can supply 47 mcg of folate, or 12% of the DV. They’re also a great source of kaempferol, an antioxidant associated with numerous health benefits. Animal studies show that kaempferol can help to reduce inflammation and prevent oxidative damage.
Read also: Primary Care Physician Weight Loss Options
Broccoli: Well known for its multitude of health-promoting properties, adding broccoli to your diet can provide an array of essential vitamins and minerals. When it comes to folate, one cup (91 grams) of raw broccoli contains around 57 mcg of folate, or about 14% of the DV. Cooked broccoli contains even more folate, with each half-cup (78-gram) serving providing 84 mcg, or 21% of the DV. Broccoli is also high in manganese and vitamins C, K, and A. It likewise contains a wide variety of beneficial plant compounds, including sulforaphane, which has been studied extensively for its powerful anti-cancer properties.
Nuts and Seeds: There are plenty of reasons to consider upping your intake of nuts and seeds. In addition to containing a hearty dose of protein, they’re rich in fiber and many of the vitamins and minerals that your body needs. Incorporating more nuts and seeds into your diet can also help you meet your daily folate needs. Raw or sprouted seeds and nuts can add a healthy serving of folate to any diet. The amount of folate in various types of nuts and seeds can vary slightly. One ounce (28 grams) of walnuts contains about 28 mcg of folate, or around 7% of the DV, while the same serving of flax seeds contains about 24 mcg of folate, or 6% of the DV.
Beef Liver: Beef liver is one of the most concentrated sources of folate available. A 3-ounce (85-gram) serving of cooked beef liver packs 212 mcg of folate, or about 54% of the DV. In addition to folate, a single serving of beef liver can meet and exceed your daily requirements for vitamin A, vitamin B12, and copper. It’s also loaded with protein, providing a whopping 24 grams per 3-ounce (85-gram) serving. Protein is necessary for tissue repair and the production of important enzymes and hormones. If you have a taste for liver, rejoice!
Wheat Germ: Wheat germ is the embryo of the wheat kernel. Although it’s often removed during the milling process, it supplies a high concentration of vitamins, minerals, and antioxidants. Just one ounce (28 grams) of wheat germ provides 78.7 mcg of folate, which equals about 20% of your daily folate needs. It also contains a good chunk of fiber, providing up to 16% of the fiber you need per day in a single ounce (28 grams). Fiber moves slowly through your digestive tract, adding bulk to your stool to help promote regularity, prevent constipation, and keep blood sugar levels steady.
Papaya: Papaya is a nutrient-dense tropical fruit native to southern Mexico and Central America. Besides being delicious and full of flavor, papaya is jam-packed with folate. One cup (140 grams) of raw papaya contains 53 mcg of folate, which is equal to about 13% of the DV. Tropical fruits, such as mangos, kiwis and pomegranate, are also good sources of folate. Additionally, papaya is high in vitamin C, potassium, and antioxidants like carotenoids. Pregnant women should consider avoiding eating unripe papaya.
Avocados: Just one more reason to love avocados is their significant amount of folate per cup - around 90 mcg.
Okra: In addition to its amazing ability to cleanse the entire digestive tract from built-up toxins, okra is a great source of folate.
Corn: Being from Iowa, we love corn - and you should too!
Cauliflower: Cauliflower is another spectacular vegetable that is not only a great source of folate, but also one of the best vitamin C foods available.
Fortified Foods as Sources of Folic Acid
You also get folate by eating foods fortified with folic acid. Folic acid is a form of folate that can be added to foods during the manufacturing process. The Food and Drug Administration (FDA) began requiring manufacturers to add 140 mcg folic acid/100 g to enriched breads, cereals, flours, corn meals, pastas, rice, and other grain products to reduce the risk of neural tube defects (NTDs). Because cereals and grains are widely consumed in the United States, these products have become important contributors of folic acid to the American diet. The fortification program increased mean folic acid intakes in the United States by about 190 mcg/day. Since November 1, 1998, the Canadian government has also required the addition of 150 mcg folic acid/100 g to many grains, including enriched pasta, corn meal, and white flour.
Foods that are fortified with folic acid include:
- Enriched breads, flours, pastas, rice, and cornmeal
- Fortified corn masa flour (used to make corn tortillas and tamales, for example)
- Certain fortified breakfast cereals
Enriched breads and pastas are made from grains that have extra folic acid added to them while being processed. These enriched foods have more than double the amount of folic acid typically found in them. Similar to enriched breads and pastas, fortified cereals have added vitamins, including folic acid. Most fortified cereals boast 100 to 400 mcg of folic acid in just a one cup serving.
To determine if a food has added folic acid, look for “folic acid” in parentheses on the label.
Folate in Dietary Supplements
Folic acid is available in multivitamins and prenatal vitamins, supplements containing other B-complex vitamins, and supplements containing only folic acid. About 85% of supplemental folic acid, when taken with food, is bioavailable. Dietary supplements containing 5-MTHF are also available. For some people, supplementation with 5-MTHF might be more beneficial than with folic acid (see People with an MTHFR polymorphism below). The bioavailability of 5-MTHF in supplements is the same as or greater than that of folic acid. However, conversion factors between mcg and mcg DFE for 5-MTHF have not been formally established.
Why Folate is Especially Important for Individuals Who Can Become Pregnant
Folate is important for lowering the risk of serious problems that occur during pregnancy that can affect the baby’s brain (anencephaly) and spine (spina bifida). Therefore, all individuals who could become pregnant should consume 400 mcg of folic acid daily either from fortified foods (such as enriched breads, flours, pastas, rice, cornmeal, corn masa flour, and certain breakfast cereals), dietary supplements, or a combination of the two, in addition to the folate they get from following a healthy eating pattern.
Women who are thinking of becoming pregnant or who are pregnant often require additional supplementation of folic acid. Adequate folic acid is important for pregnant women because it has been shown to prevent some kinds of birth defects, including neural tube defects such as spina bifida. Women who are of childbearing age should take at least 400 micrograms (mcg) of a folic acid supplement every day in addition to that found in fortified foods. Pregnant women should take 600 micrograms a day, or 1000 micrograms a day if expecting twins.
During pregnancy, demands for folate increase because of its role in nucleic acid synthesis. To meet this need, the FNB increased the folate RDA from 400 mcg DFE/day for nonpregnant women to 600 mcg DFE/day during pregnancy. This level of intake might be difficult for some women to achieve through diet alone.
Folate Deficiency
Isolated folate deficiency is uncommon; folate deficiency usually coexists with other nutrient deficiencies because of its strong association with poor diet, alcoholism, and malabsorptive disorders. Megaloblastic anemia, which is characterized by large, abnormally nucleated erythrocytes, is the primary clinical sign of folate or vitamin B12 deficiency. Women with insufficient folate intakes are at increased risk of giving birth to infants with NTDs.
Folate deficiency may cause:
- Diarrhea
- Gray hair
- Mouth ulcers
- Peptic ulcer
- Poor growth
- Swollen tongue (glossitis)
It may also lead to certain types of anemia.
Groups at Risk of Folate Deficiency
Although most people consume adequate amounts of folate, certain groups, including women of childbearing age and non-Hispanic black women, are at risk of insufficient folate intakes. Even when intakes of folic acid from dietary supplements are included, 19% of female adolescents age 14 to 18 years and 17% of women age 19 to 30 years do not meet the EAR. Frank folate deficiency is rare in the United States, but some individuals might have marginal folate status.
People with alcohol use disorder frequently have poor-quality diets that contain insufficient amounts of folate. Moreover, alcohol interferes with folate absorption and hepatic uptake, accelerates folate breakdown, and increases its renal excretion. Several medical conditions increase the risk of folate deficiency. People with malabsorptive disorders-including tropical sprue, celiac disease, and inflammatory bowel disease-might absorb less folate than people without these disorders; for example, about 20%-60% of patients with inflammatory bowel disease have folate deficiency.
People with a genetic polymorphism, 677C>T, in the methylenetetrahydrofolate reductase (MTHFR) gene have a reduced ability to convert folate to one of its active forms, 5-MTHF, because the methylenetetrahydrofolate reductase enzyme needed for this conversion is less active. About 25% of Hispanics, 10% of Caucasians and Asians, and 1% of African Americans are homozygous for the 677C>T MTHFR polymorphism. This polymorphism results in less biologically available 5-MTHF and, thus, reduced methylation potential, leading to elevated homocysteine levels and an increased risk of NTDs. Although the research on the benefits of folate supplementation for people with this genetic polymorphism is inconclusive, some of these people might benefit from supplementation with 5-MTHF.
Folate and Autism Spectrum Disorder (ASD)
Emerging evidence suggests that periconceptional folic acid supplementation might reduce the risk of ASD or mitigate the potentially increased risk of ASD from prenatal exposure to certain drugs and toxic chemicals. Some, but not all, observational studies have shown associations between maternal use of folic acid and/or multivitamin supplements before and/or during pregnancy and lower risk of ASD in the women’s offspring. Periconceptional use of folic acid might mitigate the potentially increased risk of ASD in children exposed to certain drugs and neurotoxins in utero. Overall, the evidence to date suggests a possible inverse association between mothers’ periconceptional folic acid intakes and risk of ASD in their offspring. However, most, if not all, of the currently available data are observational, and confounding weakens the ability to demonstrate causal inference.
Folate and Cancer
Several epidemiological studies have suggested an inverse association between folate intakes and status and the risk of colorectal, lung, pancreatic, esophageal, stomach, cervical, ovarian, breast, bladder, and other cancers. Research has not established the precise nature of folate’s effect on carcinogenesis, but scientists hypothesize that folate might influence cancer development through its role in one-carbon metabolism and subsequent effects on DNA replication and cell division. Evidence also indicates that folate might play a dual role in cancer initiation and progression.
Results from clinical trials involving folic acid supplementation have been mixed. In addition, most trials have included other B-vitamins (frequently at doses well above RDA levels) and sometimes other nutrients, making it difficult to disentangle the effects, if any, of folic acid alone. The most thorough research has focused on folate’s effect on the development of colorectal cancer and its precursor, adenoma.
Am I Getting Enough Folate/Folic Acid?
For most people, using the %DV can help them choose foods to get enough folate in their diet. For individuals who could become pregnant, look for the amount of folic acid in mcg listed in the parentheses on the label so you know how much you are consuming from fortified foods and dietary supplements.
Remember:
- 5% DV or less of folate per serving means the product is low in folate.
- 20% DV or more of folate per serving means the product is high in folate.
Don’t forget to include foods that have folate, such as those listed above, in your healthy eating plan.
How is Folate Listed on the Nutrition Facts label and Supplement Facts label?
The mcg DFE is the unit of measure for folate on the Nutrition Facts and Supplement Facts label.