What is Folate?

Definition and Importance

Folate, also referred to as vitamin B9, encompasses all naturally occurring compounds known as folates found in foods and dietary supplements. As a crucial member of the B vitamin family, folate plays a significant role in converting food into energy. It is classified as an essential vitamin, meaning that the body does not produce it and must obtain it through dietary sources. Additionally, folate is water-soluble, indicating that it cannot be stored in the body and must be ingested regularly for optimal health.

Sources of Folate (Vitamin B9)

Food Sources

Folate is present in a variety of foods, with some of the richest sources including spinach, asparagus, Brussels sprouts, and liver. Other plant-based sources consist of dark leafy greens, fruits, nuts, beans, peas, and grains. Animal-derived sources include poultry, eggs, and dairy products.

Fortification and Supplements

Many countries, including the United States and Canada, fortify grain products with folate to help individuals meet their nutritional requirements. The supplemental form of folate, known as folic acid, is available in folic acid supplements, multi-B complex vitamins, and numerous multivitamins. It is particularly important in prenatal vitamins due to its critical role in fetal development.

Importance of Folate

Role in Health

Folate is vital for several health functions. It aids in the metabolism of amino acids and the synthesis of nucleic acids, which are the building blocks of DNA. Furthermore, adequate folate intake is believed to reduce the risk of certain health issues during fetal development, such as spina bifida, a condition characterized by abnormal spinal cord development. Therefore, it is essential for pregnant women and those of childbearing age to ensure they consume sufficient folate.

Recommended Dietary Allowance (RDA) for Folate

Daily Intake Guidelines

The Recommended Dietary Allowance (RDA) for folate is expressed in dietary folate equivalents (DFE). One DFE is equivalent to 1 mcg of folate from food, 0.6 mcg of supplemental folic acid taken with food, or 0.5 mcg of supplemental folic acid taken without food. The RDA for folate is set at 400 DFE for men and women aged 14 years and older, with 600 DFE for pregnant women and 500 DFE for lactating women. For children, the RDAs vary: 300 DFE for ages nine to thirteen, 200 DFE for ages four to eight, 150 DFE for toddlers aged one to three, 80 DFE for infants aged seven to twelve months, and 65 DFE for infants under seven months. These guidelines, provided by the National Institutes of Health, are designed to meet the dietary needs of 97 to 98 percent of healthy individuals.

Food Examples

To illustrate, half a cup of boiled spinach contains approximately 33 percent of the RDA for folate, while half a cup of cooked enriched white rice provides about 22 percent.

Potential Risks of Excess Folate Intake

Upper Limits and Health Concerns

The Upper Limit (UL) for folate intake is set at 1000 mcg for adults over 19 years and 800 mcg for teenagers aged 14 to 18. For children, the UL is 600 mcg for ages nine to thirteen, 400 mcg for ages four to eight, and 300 mcg for toddlers aged one to three. No established UL exists for infants under one year. These values, also provided by the National Institutes of Health, represent the maximum daily intake unlikely to cause adverse health effects.

Research has indicated that excessive folate intake could pose health risks. For instance, one study noted that mothers taking folate supplements exceeding 1000 mcg during conception had children with lower cognitive development scores compared to those who took between 400 and 999 mcg. Another study found that a daily intake of 5 mg of folic acid was linked to a decreased number of natural killer cells, which are crucial for the immune system. While these findings suggest potential negative effects of high folate doses, further research is necessary for confirmation.

Impact on Vitamin B12 Deficiency

High levels of folic acid may mask symptoms of vitamin B12 deficiency, which can lead to serious neurological damage if untreated.

Benefits of Folate

Potential Health Advantages

In addition to its role in preventing birth defects, folate may offer various other health benefits. Some studies suggest that sufficient folate intake is associated with a reduced risk of several cancers, including lung, colorectal, breast, and ovarian cancers. However, additional research is needed to establish these connections.

Folic acid has also been linked to a lower stroke risk, potentially due to its ability to reduce homocysteine levels. Some research indicates that folic acid supplementation during pregnancy may correlate with a decreased risk of Autism Spectrum Disorder (ASD) in children, although the evidence remains inconclusive.

Folate Deficiency

At-Risk Populations

Folate deficiency is relatively uncommon in developed countries, but certain populations are more susceptible. Individuals with alcoholism or alcohol use disorder may face a higher risk, as alcohol can inhibit folate absorption. Those with celiac disease or inflammatory bowel disease might also struggle with folate absorption.

Pregnant women have increased folate requirements and are therefore at greater risk of deficiency. It is advisable for pregnant women and those planning to conceive to monitor their folate intake and consider folic acid supplementation.

Symptoms of Deficiency

Folate deficiency can lead to megaloblastic anemia, a condition characterized by oversized red blood cells. Symptoms may include fatigue, headaches, concentration difficulties, weakness, and shortness of breath. Other signs of deficiency may consist of mouth lesions, elevated homocysteine levels, changes in hair and skin pigmentation, and gastrointestinal issues. Additionally, pregnant women with folate deficiency are at a heightened risk of having children with neural tube defects such as spina bifida.

Folate Supplementation

Treatment and Prevention

Folate deficiency is treatable through folic acid supplements, typically administered over a four-month period. Adequate dietary folate intake can also prevent deficiency. If you suspect a folate deficiency or are at increased risk, consider consulting a healthcare professional for a blood test. Always seek medical advice before starting any vitamin or mineral supplement to avoid potential interactions with medications or health conditions.

References

Bibbins-Domingo, K., Grossman, D. C., Curry, S. J., et al (2017). Folic acid supplementation for the prevention of neural tube defects: US preventive services task force recommendation statement. JAMA, 317(2), 183-189. doi:10.1001/jama.2016.19438

Levine, S. Z., Kodesh, A., Viktorin, A., et al (2018). 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, 75(2), 176. doi:10.1001/jamapsychiatry.2017.4050

Office of Dietary Supplements – Folate. (2020, June 3). Retrieved August 29, 2020, from https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/

Paniz, C., Bertinato, J. F., & Rodrigues-Lucena, M. (2017). A daily dose of 5 mg folic acid for 90 days is associated with increased serum unmetabolized folic acid and reduced natural killer cell cytotoxicity in healthy Brazilian adults. J Nutr, 147(9), 1677-1685. doi:10.3945/jn.117.247445

Valera-Gran, D., Navarrete-Munoz, E. M., De la Hera, M. G., et al (2017). Effect of maternal high dosages of folic acid supplements on neurocognitive development in children at 4-5 years of age: The prospective birth cohort Infancia y Medio Ambiente (INMA) study. American Journal of Clinical Nutrition, 106(3), 878-887. doi:10.3945/ajcn.117.152769

Vitamin B12 or folate deficiency anaemia symptoms and treatments. (n.d.). Retrieved August 29, 2020, from https://www.nhsinform.scot/illnesses-and-conditions/nutritional/vitamin-b12-or-folate-deficiency-anaemia