Nearly 60% of Americans take dietary supplements—but increasingly, popular health influencers say people may not be seeing benefits unless they take easier-to-absorb “methylated vitamins.”
Gary Brecka, Andrew Huberman, and other health podcasters are now advertising methylated vitamins as a way to ensure your body will actually be able to use the compounds in the various supplements you’re taking.
But are these marketing claims true? Or are methylated vitamins only, as some experts say, making “very expensive urine”?
Here’s what to know about how methylated vitamins work in the body, and whether you should actually give them a try.
Vitamins that are “methylated” have a slight molecular addition to their chemical backbone—they include a methyl group, comprised of one carbon and three hydrogen molecules (CH3).
Two of the most popular methylated vitamins are both B vitamins: folate and B12.
Health influencers and supplement companies say this extra methyl molecule makes these vitamins more “bioavailable,” meaning it’s easier for the body to absorb and use as intended.
However, despite the claims, there’s little evidence that methylated vitamins are actually better for you than standard vitamins.
“There is no recommendation from any authoritative health body to supplement with methylated versions of these vitamins for the general public—or even for specific disease states,” Kevin Klatt, PhD, RD, an assistant research scientist in the Department of Nutrition Sciences and Toxicology at UC Berkley, told Health.
But how do methylated and unmethylated versions of both vitamins—folate and B12—compare to one another, and what’s actually going on in the body?
Folate vs. Methylfolate
Folate (vitamin B9) is naturally found in green vegetables, nuts, fruits, and other foods. Many cereals are also fortified with the supplement form of folate, called folic acid.
This vitamin is essential during pregnancy. However, folate has been tied to other potential health benefits too, including protecting against early cancer development and keeping the brain healthy.
Folate deficiency is very uncommon in the U.S., but guidelines recommend that people capable of becoming pregnant should get 400 micrograms of folate daily through diet or supplements.
For the body to use this vitamin, it must be converted into its active form, which is termed 5-MTHF (5-methyltetrahydrofolate or methylfolate).
The gut does this naturally when people eat foods with folates in them or take folic acid supplements. But you can also take 5-MTHF, or methylated folate, supplements, so the vitamin is already in its active form to begin with.
However, research conducted in 2004 and 2010 found that 5-MTHF is not better absorbed or more bioavailable than folic acid.
If you’re looking for the best folate absorption possible, what matters most isn’t which form you take, but when you take it.
”Take it on an empty stomach, because when folic acid [or 5-MTHF] is taken with food, you absorb [only] 85%,” Vanessa King, MS, RDN, clinical nutrition manager for Queen’s Health System in Hawaii and spokesperson for the Academy of Nutrition and Dietetics, told Health.
B12 vs. Methylated B12
Vitamin B12 is found in animal products such as beef, eggs, and fish. Adults need about 2.4 micrograms of this vitamin daily to keep blood and nerve cells healthy.
In its supplement form, companies manufacture vitamin B12 with another chemical group attached. Common forms include:
- Cyanocobalamin: B12 and a “cyanide group”
- Methylcobalamin: the methylated form of B12
It’s a similar story to folate—methylcobalamin is the active form of B12, ready to be absorbed by the body when you take it. However, the body can easily convert cyanocobalamin or other unmethylated B12 supplements to this active form, too.
Again, studies comparing B12 to its methylated counterpart haven’t found that methylcobalamin is better absorbed. There’s little “biological rationale” for the general public to take them, said Klatt.
Adding in some kind of B12 supplement may not be a bad idea, particularly for people at higher risk of deficiency. That includes:
- People taking metformin
- People with gastrointestinal disorders
- Older people
- Vegetarians and vegans
However, many vegans and vegetarians are able to comfortably hit their recommended vitamin B12 levels without supplementation, since many foods are now fortified, King added.
In general, most healthy people don’t need to take vitamins. Researchers emphasize exercising and eating a healthy diet rich in fruits and vegetables as an alternative.
But if you do want to take vitamin B12 and folate, both are water soluble, so they don’t linger in the body. King said this means “a bigger dose doesn’t equal better absorption,” but also that there’s little risk that larger doses will cause toxic effects—regardless of whether the supplement is in a methylated or unmethylated form.
There are a couple of things to watch out for, though. High doses of folate can mask the symptoms of a vitamin B12 deficiency, Rachel Kopec, PhD, associate professor of human sciences at The Ohio State University, told Health.
Plus, buying any supplement can be risky, as they sometimes contain different doses than advertised or even additional compounds.
“What’s very important with buying any supplement is looking for third-party testing and verification, so that you know what it says on the bottle is what you’re getting,” said King. “The [Food and Drug Administration] does not monitor nutritional supplements the way it monitors pharmaceuticals.”
In general, methylated vitamins are no better than their counterparts, experts agreed.
“If we’re talking about somebody who’s consuming a supplement over weeks at a time, the data doesn’t suggest that there’s really one advantage of one form over another,” said Kopec.
In fact, Klatt said choosing unmethylated supplements might even be the better choice.
Methylated vitamins can be expensive. Plus, when it comes to methylated folate, or 5-MTHF, in particular, there are additional risks, said Klatt. Many forms are susceptible to breakdown from light, oxygen, and temperature, which could present a risk for pregnant people, especially, he explained.
“Current supplements on the market use other forms of 5-MTHF that claim to be stable, but have much less data,” he said. But there’s lots of research showing folic acid is stable, Klatt explained, and for now, it’s “the only form of folate shown to be effective” in protecting development in utero.
If you’re worried about your folate or vitamin B12 levels and considering taking supplements, speak with your doctor or a registered dietitian nutritionist first. They can help you adjust your diet, look at any medications that might be interacting with your body’s nutrient intake, and monitor vitamin levels.
