Understanding the difference between folate and folic acid
Folate and folic acid are often used interchangeably, but they are not the same. Folate is the naturally occurring form of vitamin B9, found in foods like leafy greens, citrus fruits, and legumes. Folic acid, on the other hand, is the synthetic (man-made) form used in supplements and added to fortified foods like enriched bread, pasta, and cereals. Folic acid is more easily absorbed by the body than natural folate.
The importance of vitamin B9
This essential B vitamin plays a critical role in several bodily functions. It is vital for the production of red blood cells and for the synthesis of DNA, the genetic material within our cells. A deficiency can lead to folate-deficiency anemia, characterized by abnormally large red blood cells that cannot function properly.
Folic acid intake recommendations by life stage
The optimal daily amount of folic acid varies depending on your age and health status. The Dietary Folate Equivalent (DFE) was developed to account for the body's higher absorption of synthetic folic acid compared to naturally occurring folate.
For adults (19+ years): The general recommendation is a specific amount in DFE daily. Many multivitamins contain an amount suitable for adults.
For women of childbearing age: Experts, including the Centers for Disease Control and Prevention (CDC), advise all women who can become pregnant to consume a specific daily amount of folic acid. This is because neural tube defects, a category of serious birth defects, can occur in the first few weeks of pregnancy, often before a woman knows she is pregnant.
For pregnant individuals: The recommended daily intake increases during pregnancy. A prenatal vitamin containing a specific amount is often recommended to support the baby's proper development of the brain and spinal cord.
For breastfeeding individuals: The daily recommendation is a specific amount in DFE to meet the needs of both the parent and the baby.
For individuals at high risk for neural tube defects: A higher intake is typically prescribed by a doctor. This applies to women who have previously had a baby with a neural tube defect or have a family history of such defects. This higher intake should be managed under medical supervision.
Food sources and fortified products
While supplements can contribute to folic acid intake, it's also present in many foods. Foods naturally rich in folate include:
- Dark green leafy vegetables, such as spinach and asparagus
- Legumes, like lentils and peas
- Nuts and seeds
- Citrus fruits
- Beef liver and other organ meats
Since 1998, the U.S. Food and Drug Administration has required that enriched grain products be fortified with folic acid, including:
- Enriched bread, flour, and pasta
- Breakfast cereals
- White rice and cornmeal
Potential risks of excessive folic acid
For most people, exceeding typical daily intake from food is not a concern. However, a Tolerable Upper Intake Level (UL) has been established for synthetic folic acid.
- Upper Limit: The UL for adults is a specific amount of synthetic folic acid daily. This limit does not apply to folate naturally found in food.
- Masking Vitamin B12 Deficiency: The primary reason for this limit is that high intakes of folic acid can mask the symptoms of a vitamin B12 deficiency. This can be dangerous because a B12 deficiency can lead to irreversible nerve damage if left untreated.
- Other Potential Considerations: High intakes of folic acid have been linked to potential side effects like stomach upset, nausea, and irritability, and some studies suggest a possible link to increased cancer risk, though more research is needed.
Folic acid vs. natural folate: a comparison
| Feature | Natural Folate (Food) | Synthetic Folic Acid (Supplements & Fortified Foods) |
|---|---|---|
| Source | Found naturally in foods | Man-made, added to supplements and fortified foods |
| Absorption | Less efficiently absorbed by the body | More easily absorbed by the body |
| Measurement | Measured in micrograms (mcg) | Measured in micrograms (mcg), but higher absorption is factored into DFE |
| Regulation | No upper intake level (UL) | Has a tolerable upper intake level (UL) for adults |
| Risk of Excess | Extremely rare to reach levels of concern from food alone | High intakes can mask B12 deficiency |
How to choose a folic acid supplement
When selecting a supplement, consider the following factors:
- Amount: Most multivitamins for adults contain a typical amount, while prenatal vitamins will have a higher dose. Always check the label to ensure the supplement provides an appropriate amount for your needs.
- Form: Folic acid is available in tablets, capsules, and liquids. Tablets are a common and convenient option.
- Third-Party Certification: Look for certifications like USP or NSF on the label. These seals indicate that the product has been tested for quality and contains the ingredients listed.
- Special Considerations: For certain genetic variations, like the MTHFR polymorphism, some individuals may have a reduced ability to convert folic acid to its active form, 5-MTHF. While many experts still recommend folic acid, some may prefer a supplement with 5-MTHF. Discuss this with a healthcare provider.
Conclusion
Understanding the proper daily intake of folic acid is essential for overall health, especially for women of childbearing age and pregnant individuals. The recommended daily intake varies by life stage. While natural folate is found in many foods, synthetic folic acid from supplements and fortified products is more readily absorbed by the body. It is important to be mindful of the upper intake limit for synthetic folic acid to avoid masking a vitamin B12 deficiency. By making informed choices about diet and supplementation, individuals can ensure they receive an appropriate amount of this vital nutrient. Find more health resources here.
