Folate is critical in supporting a healthy pregnancy and should be supplemented by all women who could become pregnant. Methylfolate is the active form of folate and is preferred to folic acid, which is the synthetic form. Recommendations for folate intake are 400 mcg prior to pregnancy, 600 mcg during, and 500 mcg while breastfeeding.
What is folate and why do I need it?
Folate is a general term used to describe a water-soluble B vitamin, known as B9. It is one of the 13 essential vitamins, meaning it cannot be synthesized by our bodies and must come from an external source through diet or supplementation. As a water-soluble vitamin, folate gets flushed out of the body readily and needs to be replenished to maintain the levels needed.
The term folate generally refers to one of three forms of this compound: dietary folate, folic acid, or methylfolate. Dietary folate is the naturally occurring form of folate found in foods. Folic acid is the synthetic form that is commonly added to processed foods or supplements. Both of these forms must be converted to methylfolate, which is the metabolically active form that our bodies can utilize. Methylfolate, which is often referred to as L-MTHF, is also available in supplement form.
Folate, Folic Acid, and 5-MTHF: How are they different?
Recommendations for folate are given in values of Dietary Folate Equivalents (DFE) to account for the varied bioavailability of the different forms of folate. DFEs, as determined by the National Academy of Medicine (NAM), are listed below :
- 1 mcg DFE = 1 mcg of dietary folate
- 1 mcg DFE = 0.6 mcg of folic acid from fortified foods or supplements when consumed with a meal
- 1 mcg DFE = 0.5 mcg of supplemented folic acid when taken on an empty stomach
While official guidelines haven’t been established for a conversion between methylfolate and DFE, the Food and Drug Administration (FDA) did respond to this consideration, stating that the conversion factor for L-MTHF is comparable to folic acid . Other studies have backed this with findings that L-MTHF is as bioavailable as folic acid . So from a DFE perspective, L-MTHF and folic acid are equivalent.
Folate in Pregnancy and Prior to Conception
Folate is essential for cell growth, DNA formation, proper nerve and brain functions, and amino acid metabolism. It is especially critical during pregnancy and infancy, as these are periods of rapid cell division and development. Low folate levels are associated with low infant birth weight and preterm delivery.
Folate is critical in reducing the risk of a very critical condition called neural tube defects (NTDs) in the fetus. NTDs are malformations in the spine (spina bifida), skull, or brain (anencephaly), which are caused by the failure of the neural tube to close between 21-28 days after conception . Since many women may not even know that they are pregnant in the first few weeks and around half of all pregnancies are unplanned, it is important to supplement prior to conception.
How much folate do I need?
The recommendation is that all women and teen girls who could become pregnant supplement folate. Folate needs increase during pregnancy and lactation so the recommended amounts are higher.
The National Academy of Medicine (NAM) provides the Recommended Dietary Allowances (RDA) :
- All Women: 400 mcg DFE
- During Pregnancy: 600 mcg DFE
- During Lactation: 500 mcg DFE
Folic acid is controlled and mandated by the FDA, so the standard recommendations report 400 mcg of folic acid supplementation . However, let’s review why L-MTHF is actually the preferred form of supplementing for suggested DFE intake.
What’s wrong with folic acid?
We’ve established that folic acid and L-MTHF are around 2 times more bioavailable than dietary folate, meaning they can be absorbed by our bodies more efficiently. And if that was the full story, we’d leave it there and recommend folic acid, as it is far cheaper to create and is currently used in the majority of the prenatal vitamins on the market.
However, in order for our bodies to turn folic acid into the active form for our bodies, we use an enzyme called methyltetrahydrofolate reductase (MTHFR). Recent studies have shown that 40-60% of the population has a genetic mutation that impairs this conversion , making folic acid virtually unusable by the body for that segment of the population.
If you know that you have an MTHFR mutation, you should opt for a supplement with methylfolate instead of folic acid, since it is already in the chemical form that can be utilized.
Many research papers that cite the possible linkage between certain types of cancer and high intakes of folic acid, but several meta-analyses have stated that it is currently inconclusive and further research is needed [6, 7]. As the research continues, we just have to make our own call on this. Other studies point out that L-MTHF is more beneficial than folic acid as it does not mask vitamin B12 deficiencies and helps prevent anemia after pregnancy [8, 9].
It is known that a high intake of folic acid can cause adverse health effects so the NAM has established an upper intake level (UL) of 1,000 mcg per day. Due to the increased consumption of folic acid through fortified foods and possible additional folic acid in supplements, it is certainly possible to exceed that UL intake.
The UL is not set for dietary folate or L-MTHF and there are no known health risks associated with excess intake. Folate, being water-soluble, flushes out through urine when there is more available than the body needs.
Can I get enough folate from food?
The word folate comes from the Latin “folium”, which means leaf. This is a great way to remember that folate concentration is high is leafy vegetables such as spinach, turnip greens, romaine lettuce, and bok choy. Many other foods are a great source too, including edamame, peanuts, lentils, asparagus, broccoli, beets, and beans.
To give you an example, 1 cup of prepared edamame has 482 mcg and 1 cup of cooked spinach has 263 mcg of DFE . Not bad, considering the general recommendations call for 400 mcg daily. With a whole food, plant-based diet, you’re likely to be getting plenty of folate in the meals you are already eating.
I want to be clear though that supplementation is recommended in addition to a folate-rich diet for all women who could become pregnant. This makes a lot of sense, considering how critical folate is to the development of a fetus. Also, during pregnancy, it is possible that due to morning sickness, fatigue, or food aversions, you’re simply not getting enough dietary folate.
Vegan Supplements with Folate
Majority of the prenatal vitamins contain folic acid, but here is a list of prenatal vitamins that have the methylfolate form (or folate from food, as in the case of Garden of Life).
Many supplements that do contain folate are not listed here because of their vitamin D3 form (cholecalciferol comes from sheep’s or lamb’s wool but lichen is plant-based).
As you can see, the list is short. During my pregnancy, I chose to combine a vegan prenatal supplement that has no folate in any form (Dr. Fuhrman’s Gentle Prenatal) with a B12 supplement that I was already taking, which contains methylfolate (Metagenics Intrinsi F12-Folate).
I reached out to Dr. Fuhrman to ask why folate is missing from the prenatal supplement, and the response was that folate needs “can easily be met by eating green vegetables, beans and other whole plant foods”. While I agree with that statement, I believe that adequate folate intake is so critical prior to and during pregnancy, and considering that there are no adverse effects of folate, I personally chose to supplement with it as an insurance policy.
Please talk to your health care provider about their recommendations.
Other Names for L-MTHF
As you read the labels of supplements, keep in mind that L-MTHF can be listed by a variety of other names. Here’s a list of ones that are used but are, in fact, the same:
- Methylated folate
- Calcium L-methyltetrahydrofolate
To read about even more forms of folate and how they differ, check out MTHFR.net.
- Supplement with 400 mcg of folate daily if there’s a chance that you could become pregnant.
- Increase supplementation to 600 mcg during pregnancy and 500 mcg while breastfeeding.
- Find a vegan supplement with the L-MTHF form of folate or a food blend.
- Eat a varied diet of leafy greens and other plant-based foods that are high in folate.