Everything You Ever Wanted to Know About Folate (Brought to you by Seed)

Folate—your mom says you need it. Your grandma says you need it. Your doctor says you need it. The Internet says you need it. But what exactly is folate and why is it important?

And did you know bacteria can make it?

Our friends at Seed know a lot about bacteria—especially the trillions of them that live in and on you and, alongside viruses, fungi, and yeast, constitute your microbiome. These microbes are essential to your health—performing critical functions like aiding in digestion and modulating immune responses. As women, we have an especially unique relationship with bacteria—we ‘seed’ our children with their first microbes—these inform immune and digestive system development and set a foundation for health. From birth, through key life stages and moments like fertility, pregnancy, and menopause, bacteria play a significant role.

So when Seed told us that beneficial bacteria can actually increase folate production in the body, we had to know more. Hear it from them:

First things first. What is folate?

Folate (vitamin B9) is a crucial micronutrient1 that supports the synthesis, repair, and function of DNA and RNA—the basic building blocks of life. This means it plays a critical role in creating and maintaining new cells, particularly during pregnancy and infant development—which is why you’ve likely heard about folate and fertility, pregnancy, neural tube development, and the prevention of serious birth defects. In fact, its role in prenatal health has resulted in two Nobel prizes and is viewed as one of the most important medical discoveries of the century.


Folate is not just for expectant mothers, though. It’s also responsible for red blood cell production and is vital in preventing anemia. Folate deficiency has also been linked to elevated blood levels of an amino acid called homocysteine2, which has emerged as a risk factor for heart disease and stroke. And for fathers-to-be, it also plays a role in male fertility and improving sperm count.

All to say, it’s a pretty important vitamin. Which is why it is recommended that adults consume at least 400 mcg (micrograms) of folate each day. Women who are looking to conceive or are pregnant should be getting upwards of 600-800 mcg per day.

What are some sources of folate?

The name ‘folate’ is derived from the Latin term folium, meaning leaf or foliage (a great cheat sheet when grocery shopping!) As you can imagine, this means folate is naturally present in foods—especially of the leafy and green variety; think spinach, lettuce, brussels, broccoli, avocados. Citrus fruits, beans, lentils, and offal are also folate-rich.

Beyond diet, many women are routinely advised to fortify and supplement further, generally in the form of folic acid.

Are folic acid and folate the same? (Hint: no. And here’s a quick history.)

While often used interchangeably, folic acid and folate are not the same thing. Folic acid is a synthetic form of folate first created in the 1940s. Being highly stable, it’s the most common form of this nutrient added to dietary supplements.

In 1998, folic acid was introduced as part of a mandatory food fortification program, based on overwhelming evidence that supplementation before conception and during early pregnancy prevented neural tube defects, like spina bifida and anencephaly, in newborns. The concern—NTDs occur so early in pregnancy (within the first month) that damage might already be done before an expectant mother knew to boost her folate intake. The thesis—fortifying the food supply (by adding folic acid to all enriched bread, flour, cornmeal, rice, pasta, and grains on store shelves) was the most efficient way to reach most women of childbearing age. It worked—the birth prevalence of NTDs has decreased by 35% in the U.S., with some 1,300 babies born each year spared from its effects.

However, we now know folic acid and folate enter the metabolic cycle in different ways. Folic acid first undergoes reduction and methylation in the liver, where an enzyme called dihydrofolate reductase (DHFR) converts it to tetrahydrofolate (THF) before another enzyme called methylenetetrahydrofolate reductase (MTHFR) finally converts that to methylfolate (5-MTHF), the bioavailable (meaning, your body can absorb and use it) form of folate. But, DHFR activity in the human liver is generally fairly low. An abundance of folic acid intake could mean unexpected levels of unmetabolized folic acid circulating in the system.

Some 20-40 percent of the population does not tolerate folic acid, due to a gene mutation called MTHFR, which means they don’t produce enough or any of the enzyme responsible for that last stage and can’t adequately process folic acid into a usable state. For these people especially, buildup of folic acid in the liver can actually cause damage.

If you do choose to supplement, the bioavailable form of folate (5-MTHF or methylfolate) is recommended (especially for those with the MTHFR mutation) as an alternative to folic acid.

Your internal pharmacy

The conversation around folate has alway been rooted in supplementation (whether through diet or products). This is because, by definition, vitamins are essential nutrients our bodies can’t produce on their own. Perhaps it would surprise you, then, to learn that each of us houses an internal pharmacy that’s actually synthesizing some of these essential vitamins, including folate.

Meet your microbiome

To see this in action, we first have to travel to your gut, which is home to the majority of your microbiome (the community of 38,000,000,000,000 microorganisms that live in and on you). These beneficial microbes, mostly bacteria, reside along your epithelial wall and perform functions critical to your health. Though most well known for their role in digestive and immune health, they are also responsible for many other key functions:

  • Maintain your gut barrier integrity so inhospitable bacteria can’t penetrate. They do this by influencing mucus composition3 and collaborating closely with your gut’s ‘gatekeepers’ (tight junctions) to modulate what should (i.e. nutrients) or shouldn’t (i.e. undigested food particles or pathogenic bacteria) pass through to the bloodstream.
  • Maintain an acidic environment to dissuade certain alkaline-loving pathogenic bacteria from taking root.
  • Produce neurotransmitters that stimulate muscle contractions (yes, we’re talking about easier poops).
  • Break down food we otherwise couldn’t—think complex carbohydrates, like fiber.
  • Produce short-chain fatty acids, like butyrate, which fuel the cells lining your colon, strengthen your protective intestinal mucosa, and offer powerful anti-inflammatory effects beyond the gut, reducing oxidative stress (imbalance between free radicals and detoxifying antioxidants) and managing the production of regulatory T-cells (the ones that help your body distinguish between self and intruder).

But, what do bacteria have to do with folate?

Well, on top of all of those critical roles, certain strains of bacteria can also biosynthesize vitamins in your colon —vitamin K (menaquinones) and most of the water-soluble B vitamins including biotin (B7), nicotinic acid (B3), riboflavin (B2), thiamine (B1), pyridoxine (B6), pantothenic acid (B5), cobalamin (B12), and of course, folate (B9). That means, a continuous, complementary, and endogenous source of these essential vitamins—created, absorbed, and utilized by your body, right from your colon.

These discoveries have unveiled new applications for beneficial bacteria (probiotics), and are testament to their impact beyond simple digestive issues. At Seed, we’re incredibly excited about the future of microbiome science and how understanding the function (not just identity) of probiotic strains can translate into systemic benefits for human health.


Seed’s Female Daily Synbiotic is the first to include probiotic strains that increase folate production from within the body. Due to overwhelming response, it sold out shortly after Seed’s launch, but you can preorder to reserve your supply (ships in early 2019) with code BM15 for 15% off your first month. Happy Seeding!

Featured image by Kat Love
1Crider, K. S., Yang, T. P., Berry, R. J., & Bailey, L. B. (2012). Folate and DNA methylation: a review of molecular mechanisms and the evidence for folate’s role. Advances in nutrition (Bethesda, Md.), 3(1), 21-38.
2 Zhang, D., Wen, X., Wu, W., Guo, Y., & Cui, W. (2015). Elevated homocysteine level and folate deficiency associated with increased overall risk of carcinogenesis: meta-analysis of 83 case-control studies involving 35,758 individuals. PloS one, 10(5), e0123423. doi:10.1371/journal.pone.0123423
3 Sicard, J. F., Le Bihan, G., Vogeleer, P., Jacques, M., & Harel, J. (2017). Interactions of Intestinal Bacteria with Components of the Intestinal Mucus. Frontiers in cellular and infection microbiology, 7, 387. doi:10.3389/fcimb.2017.00387
4 Rossi, M., Amaretti, A., & Raimondi, S. (2011). Folate production by probiotic bacteria. Nutrients, 3(1), 118-34.

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