Vitamin B12 already has a respectable résumé.

It helps make red blood cells.

It supports the nervous system.

It keeps certain metabolic pathways running.

And if you’re deficient, things can go sideways pretty quickly.

But a new study suggests B12 might have another, much more unexpected role:

Helping compensate for errors in the way cells process genetic instructions.

That is a very different job description.

Researchers studying a rare genetic condition called Verheij syndrome found that vitamin B12 could rescue major growth and metabolic problems in a tiny laboratory worm carrying a similar genetic defect.

The findings are early.

Very early.

But they reveal something fascinating about the connection between genes, metabolism, and nutrition.

Let’s unpack it.

First: Your Genes Need Editing

Your DNA contains instructions for making proteins.

But those instructions are not delivered to the cell as a perfectly polished final draft.

Instead, cells first create a rough copy called pre-mRNA.

That copy contains useful sections called exons and extra sections called introns.

Before the final message can be used to make a protein, the introns have to be removed.

This editing process is called:

RNA splicing.

Think of it like editing a movie.

The raw footage contains everything.

The spliceosome cuts out the unwanted scenes and stitches the important ones together.

Done correctly?

You get a functional protein.

Done incorrectly?

The final product may be incomplete, misshapen, or useless.

Meet PUF60

One of the proteins helping with this editing process is called PUF60.

PUF60 helps the cell recognize where pieces of RNA should be cut and joined.

Some people are born with mutations that reduce the amount or function of PUF60.

That can cause a rare genetic disorder called Verheij syndrome.

People with the condition may experience:

  • Delayed growth
  • Short stature
  • Developmental problems
  • Neurological abnormalities
  • Recurrent infections
  • Multiple organ involvement

There is currently no treatment that directly targets the underlying biological problem.

Researchers wanted to understand exactly what goes wrong inside cells when PUF60 does not work properly.

So Naturally, Scientists Studied Worms

The star of this experiment was Caenorhabditis elegans.

Or, as its friends call it:

C. elegans.

This microscopic worm is one of biology’s favorite lab animals because:

  • Its genes are well mapped.
  • It develops quickly.
  • Scientists can manipulate its DNA easily.
  • Many basic cellular pathways are shared with humans.

The worm version of PUF60 is called RNP-6.

When RNP-6 does not work normally, the worms develop problems that resemble parts of Verheij syndrome.

They become:

  • Smaller
  • Slower-growing
  • Neurologically abnormal
  • Immunologically altered

That gave researchers a living model for studying what the gene defect actually does.

Then Something Weird Happened

Scientists normally feed laboratory worms bacteria.

Different strains of bacteria can provide slightly different nutrients.

Researchers noticed something unexpected.

Worms with the RNP-6 mutation grew poorly when eating one standard bacterial strain.

But when they ate a different strain?

Their growth problems largely disappeared.

That is the scientific equivalent of:

“Wait…what?”

The genetic mutation was still there.

The worms had not been genetically repaired.

Something in the food was compensating for the defect.

So researchers started digging.

The Mystery Ingredient Was Vitamin B12

Eventually, the investigators traced much of the effect to:

Vitamin B12.

The bacteria that rescued the worms provided more B12.

When researchers gave B12 directly to the mutant worms, many of their developmental problems improved dramatically.

That was surprising.

Because the original problem was a defective RNA-splicing protein.

So how does a vitamin compensate for faulty genetic editing?

The answer appears to involve metabolism.

B12 Is Part of a Cellular Assembly Line

Vitamin B12 helps run the methionine cycle.

This pathway produces a molecule called:

S-adenosylmethionine, or SAM.

SAM is essentially one of the body’s major methyl donors.

Think of methyl groups as tiny chemical tags that cells attach to:

  • DNA
  • Proteins
  • Lipids
  • Other molecules

These tags help regulate how cells function.

SAM is also important for producing phosphatidylcholine, a major type of fat used to build cell membranes.

So the chain looks roughly like this:

Vitamin B12 → Methionine → SAM → Healthy methylation + phosphatidylcholine

The mutant worms had disruptions in this metabolic chain.

Their ability to produce and balance these molecules was impaired.

B12 helped restore it.

The Genetic Error Created a Metabolic Problem

This may be the most interesting part of the study.

The mutation did not simply cause bad RNA.

It caused bad RNA that disrupted metabolism.

One especially important gene was called nhr-114.

Normally, this gene helps regulate:

  • Methionine metabolism
  • Lipid metabolism
  • Cellular nutrient balance

But the defective splicing machinery processed nhr-114 incorrectly.

That triggered a cascade.

Methionine metabolism became disrupted.

SAM levels became abnormal.

Important membrane fats became imbalanced.

And growth slowed.

Researchers identified this altered splicing as a major connection between the original genetic defect and the downstream metabolic problems.

Basically: A Gene Problem Became a Nutrition Problem

Here’s the simplest way to think about it.

Imagine a factory with broken software.

The factory starts producing the wrong instructions.

Those faulty instructions affect the machinery that processes raw materials.

Eventually, production slows.

Researchers could not fix the software.

But they discovered that supplying more of a critical raw material allowed the factory to function better anyway.

That raw material was B12.

This is called a metabolic bypass.

The underlying mutation remains.

But the cell gets enough nutritional support to work around part of the damage.

And B12 Wasn’t the Only Thing That Helped

Researchers found that other compounds in the same metabolic pathway could also improve development.

These included:

  • Methionine
  • Choline
  • B12-rich bacteria

All of them ultimately helped restore the balance of molecules involved in methylation and membrane production.

That strengthens the idea that researchers had found a real metabolic bottleneck rather than a random vitamin effect.

Then mTOR Entered the Chat

Another important player was mTORC1.

mTOR is one of the cell’s major nutrient sensors.

Its job is basically to ask:

“Do we have enough resources to grow?”

When nutrients are abundant, mTOR promotes:

  • Growth
  • Protein synthesis
  • Cell building

When resources are scarce, mTOR slows things down.

The mutant worms showed reduced mTOR signaling.

When B12 restored the metabolic pathway?

mTORC1 became more active.

Growth resumed.

So the researchers propose something like:

Splicing defect → metabolic disruption → nutrient stress → lower mTOR activity → impaired growth

And B12 helped interrupt that chain.

It Went Beyond Growth

The mutant worms also showed signs of broader metabolic stress.

Researchers found abnormalities related to:

  • Mitochondrial function
  • Energy production
  • NAD+ metabolism
  • Glucose metabolism
  • Fat metabolism

B12 improved several of these abnormalities.

In other words:

The vitamin was not simply making the worms bigger.

It appeared to shift their metabolism from a stressed, breakdown-oriented state toward a more growth-supportive state.

Did Researchers Find Anything Similar in Humans?

Yes.

But this is where expectations need to stay very grounded.

Researchers also analyzed blood from people with Verheij syndrome.

They found abnormalities in several of the same general metabolic pathways seen in the worms, particularly pathways involving:

  • Methionine
  • Cysteine
  • Phospholipids
  • Lipid metabolism

That is encouraging.

But the human data were limited.

Some metabolites changed in the same direction as the worm model.

Others changed in the opposite direction.

The researchers themselves emphasized that larger, age- and sex-matched patient studies are needed.

Most importantly:

They have not yet demonstrated that vitamin B12 treats Verheij syndrome in humans.

This May Be Bigger Than One Rare Disease

PUF60 is only one component of the spliceosome.

There are many others.

Mutations in several splicing proteins can cause rare disorders collectively known as:

spliceosomopathies.

Interestingly, when researchers disrupted another splicing protein called PRPF19 in the worms, they saw similar metabolic abnormalities.

That raises an intriguing possibility:

Some genetic disorders caused by defective RNA splicing may share a common downstream metabolic problem.

And if that is true…

Certain nutrients might someday help compensate for some of those defects.

That would be a very different approach to genetic disease.

Instead of repairing the mutation directly:

Fix the metabolic consequences downstream.

So Should People With Verheij Syndrome Start Taking Huge Doses of B12?

No.

Not based on this study.

This research primarily showed that B12 worked in a worm model.

The researchers have not yet shown that supplementation:

  • Improves growth in patients
  • Improves neurological symptoms
  • Reduces infections
  • Corrects developmental problems
  • Changes long-term outcomes

And while B12 is generally considered a safe nutrient, that does not mean every experimental use is automatically effective—or that more is always better.

The study identifies a promising hypothesis.

It does not provide a treatment protocol.

Why This Study Is Still Exciting

Rare genetic diseases are often difficult to treat because the problem is written directly into the DNA.

That usually leaves researchers with difficult options:

  • Gene therapy
  • RNA therapy
  • Protein replacement
  • Symptom management

This study suggests another possibility.

Sometimes a genetic defect may create a metabolic weakness that can be partially bypassed.

And that opens the door to something much simpler:

Nutrition.

Not as a cure for the mutation.

But potentially as a way to help cells function better despite it.

That is a powerful idea.

The Bottom Line

Researchers studying a rare genetic disorder caused by PUF60 deficiency discovered that faulty RNA splicing can disrupt vitamin B12-dependent methionine metabolism, methylation capacity, and cell-membrane lipid production.

In a worm model, vitamin B12 restored much of that metabolic balance and rescued major growth abnormalities.

Early human blood analyses suggest people with Verheij syndrome may also have abnormalities in some of these metabolic pathways, but researchers have not yet shown that B12 supplementation treats the condition in people.

So we are nowhere near:

“Vitamin B12 cures a genetic disease.”

But we may be looking at something more scientifically interesting:

A genetic mistake created a metabolic bottleneck—and a nutrient helped the organism route around it.

Sometimes biology does not give you a way to rewrite the faulty instructions.

Sometimes it gives you another road around the traffic jam.

Kölschbach J, Dafsari HS, Baum E, Löhrke A, Kew C, Dikic I, Huang W, Antebi A. Vitamin B12 alleviates spliceosomopathy via phospholipid remodeling. Nat Commun. 2026 Aug 7;17(1):8011. doi: 10.1038/s41467-026-76295-9. PMID: 42567856; PMCID: PMC13451374.