The Finer Points of Folate (And Its Synthetic Cousin, Folic Acid)

Fortifying foods with folic acid is considered one of the most successful public health initiatives of the past 75 years.  

Folic acid is the synthetic form of folate, a water-soluble B vitamin, and maintaining optimal levels is critical for a healthy pregnancy. Folate deficiency in the earliest stage of pregnancy is associated with increased risk of birth defects. Because roughly half of all pregnancies in the United States are unplanned, adding folic acid to whole wheat (and, hence, any product made with wheat, like cereal and noodles) can help support a healthy pregnancy before a woman knows she’s pregnant.

In 1998, the United States Food & Drug Administration mandated that folic acid be added to all grain products to reduce the incidence of neural tube defects (NTDs) in newborns. The mandate worked. Studies show that the incidence of NTDs in the United States has fallen anywhere from 19 to 32 percent since the late ’90s. Today, 53 countries across the globe require that folic acid be added to wheat flour.

But the vitamin’s power extends beyond its ability to support a healthy pregnancy. There are eight different types of naturally occurring folates, and “they all do great stuff all over the body all the time,” says Kara Fitzgerald, N.D., a functional medicine practitioner and author of Methylation Diet & Lifestyle.

Folate helps with DNA and RNA synthesis, iron absorption, red blood cell production, and immune cell production. Healthy levels of folate also help control homocysteine, an amino acid that’s linked to inflammation.

In short, we all need folate. “Fortifying foods with folic acid is a public health success story,” says Fitzgerald. “We don’t want to minimize the power of that.”

Yet mandatory fortification has come with some unintended health consequences. It has also stolen the spotlight from natural folates, which occur in food and can be taken in supplement form—and are easier for the body to absorb.

One issue with folic acid? It requires more metabolic steps to be transformed into folate. In short, converting folic acid to folate inside the body is an inefficient process —and that’s in the healthiest of individuals. Some people have genetic mutations that make folic acid even more difficult to turn into folate.   

This inefficient process can result in high levels of folic acid circulating in the body, which has an inhibitory effect on the production of natural folate. Research suggests that too much circulating folic acid is associated with initiating or propagating certain cancers. So you want to be mindful if you eat a lot of folate-fortified grains.

At the same time, too little circulating folic acid is also associated with certain cancers. “It’s a U curve,” says Fitzgerald.  

Increasingly, it’s possible to find affordable, high-quality folate in supplement form. (Folic acid was originally used to fortify foods because it was cheaper than folate and more shelf stable.) But perhaps the best way to get the right balance of folate is with whole foods.

“There is no research out there that shows food-based folate is associated with cancer,” says Fitzgerald. “You can pig out on all the greens you want, and no data shows there’s a negative.”

Want to optimize folate at mealtime? The top five folate-containing foods are liver, legumes, sunflower seeds, spinach, and asparagus, says Romilly Hodges, M.S., C.S.N., C.N., director of nutrition programs for Fitzgerald’s office.

Supplements might still be necessary, says functional medicine researcher Russell Jaffe, M.D., Ph.D. Even with the healthiest diet, it can be hard to get all the folate and B-complex vitamins we need for optimal health and/or a healthy pregnancy.  

Look for a supplement in which all the ingredients are active, says Jaffe. “In the ‘other ingredients’ category? It should have none,” he says. “Proprietary blends cover a multitude of sins.”

Opt for a B-complex that has a balance of B vitamins, including folate, he continues, and perhaps most important of all, consult a trusted practitioner. “I want people to know how important it is to work with a knowledgeable functional medicine coach, doctor, or practitioner,” says Jaffe. “There is a lot of marketing bamboozlery. If I was a consumer, which I also am, I would want someone who stays current on what was real and what wasn’t. There’s lots of phony stuff out there.”