MTHFR Activity
MTHFR converts synthetic folic acid into the active methylfolate your body uses. Reduced function is common, affecting up to 40% of people. If you're one of them, standard prenatal vitamins and fortified foods won't cut it. Methylfolate supplementation bypasses the bottleneck entirely.
What this measures
How your DNA shapes mthfr activity.
MTHFR is the enzyme that converts folate from your food into the active form (5-methyltetrahydrofolate) your body uses for methylation — the process that builds neurotransmitters, regulates DNA expression, and clears homocysteine. It sits at one of the most consequential nodes in the methylation cycle.
C677T and A1298C are the two variants most people have heard of, and they often show up together. Carriers of one C677T copy are associated with enzyme activity around 65% of typical. Two copies, around 30%. The A1298C variant shifts the picture again, and the surrounding methylation-cycle genes (MTR, MTRR, BHMT, COMT, CBS) all interact with what MTHFR can do.
Methylated folate (5-MTHF) bypasses the conversion step entirely. So does folate-rich food — leafy greens, asparagus, beans. Synthetic folic acid, the form added to fortified flour, is the form the enzyme has to work hardest to process. Alcohol depletes folate. B12 status matters because the cycle stalls without it.
The reason your aunt swears by methylfolate and your friend says regular folic acid works fine isn’t preference. It’s biochemistry. Knowing which version of MTHFR you carry — and which related variants came along for the ride — changes what you’d actually want on your plate, and what to ask your provider about.
MTHFR Activity is one specific finding in this system. Your Genomic Lifestyle Optimization Report shows where your variants place you on the detoxification pathways spectrum — and what you can do about it.
In your report
Where MTHFR Activity lives inside your Genomic Lifestyle Optimization Report.
MTHFR Activity renders as a dark-background card with a color marker calibrated to your specific variants. The card opens with the gene mechanism, shows your result at a glance via that marker, and closes with a practical, mechanism-led recommendation — what to eat, what to time, what cofactors to support.
Want to see what a real Mosaic dark card looks like? Walk through a sample report →
In context
Phase II Pathways: the 4-insight cluster.
MTHFR Activity is one finding in a tightly-related cluster. Mosaic sequences the other 3 alongside it so you see the whole biology — not an isolated data point.
- AcetylationThis pathway handles histamine, caffeine, and a long list of chemicals and medications. Slow acetylators often experience fragrance sensitivity, medication side effects, or react to things that most people tolerate. Once you know, you can support the bottleneck instead of wondering why everything bothers you.
- Glutathione Support NeedsGlutathione is your body's master antioxidant—the one that recycles all the others. Some people produce plenty; others run chronically low without knowing it. Lower genetic output is common and responds well to precursors like NAC, glycine, and selenium. This is often the missing piece for people who "do everything right" but still feel run down.
- MethylationMethylation is the behind-the-scenes regulator of detox, neurotransmitter production, and gene expression. Suboptimal activity is surprisingly common—and highly responsive to the right form of B-vitamins. If you've ever taken B-complex and felt nothing (or worse), this is probably why.
Questions people ask
About MTHFR Activity.
- How does my DNA influence mthfr activity?
- Phase I (CYP450 enzymes), Phase II (sulfation, glucuronidation, methylation), and Phase III (transport) — the three-act process by which your body neutralizes everything from caffeine to alcohol to environmental compounds. Genetic variants in any phase shift the kinetics, and the bottleneck moves accordingly.
- What kind of test do I need to see my MTHFR Activity result?
- Whole-genome sequencing at 30× clinical depth. Consumer SNP-chip tests like 23andMe or AncestryDNA only read ~0.02% of your DNA and miss most of the variants this analysis needs. Mosaic reads all 3 billion base pairs and produces the full 108-insight report.
- How is MTHFR Activity different from clinical lab testing?
- Clinical labs measure downstream biomarkers — blood levels, hormone values, metabolic byproducts — at a single point in time. Genomic insights like MTHFR Activity reveal the underlying variant that shapes the biology, which is constant for life. The two are complementary: labs show the current snapshot; genomics shows the long-term tendency and where lifestyle leverage is highest.
More from Detoxification Pathways
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Acetylation
This pathway handles histamine, caffeine, and a long list of chemicals and medications. Slow acetylators often experience fragrance sensitivity, medication side effects, or react to things that most people tolerate. Once you know, you can support the bottleneck instead of wondering why everything bothers you.
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Glutathione Support Needs
Glutathione is your body's master antioxidant—the one that recycles all the others. Some people produce plenty; others run chronically low without knowing it. Lower genetic output is common and responds well to precursors like NAC, glycine, and selenium. This is often the missing piece for people who "do everything right" but still feel run down.
Read insight →detoxification pathways
Medication Metabolism
The enzyme family that processes roughly half of all prescription drugs. Your version determines whether standard doses work perfectly, cause side effects, or barely register. This prevents the trial-and-error prescribing that leaves people cycling through medications, wondering why nothing works right.
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Methylation
Methylation is the behind-the-scenes regulator of detox, neurotransmitter production, and gene expression. Suboptimal activity is surprisingly common—and highly responsive to the right form of B-vitamins. If you've ever taken B-complex and felt nothing (or worse), this is probably why.
Read insight →
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