Cold Exposure and Vitamin D
Why I Don’t Get Winter Blues — And Why Cold Exposure Might Be the Real Vitamin D Boost You Didn’t Know You Needed
By Laura Hof
(Yes, the woman who willingly swims in frozen lakes.)
Every winter, people look at me with this mixture of shock and pity.
“Laura… how are you not depressed?”
“Don’t you get winter blues?”
“Are you sure you enjoy this cold stuff?”
And every winter I smile — the kind of smile that comes from deep inside the nervous system — and say:
“Winter doesn’t drain me. Winter trains me.”
Because here’s the wild truth most people don’t know:
Cold exposure is one of nature’s secret winter survival codes.
And it might even help your body boost its Vitamin D pathways — yes, even when the sun disappears.
Let’s dive into this (preferably not into 4°C water… but you know I’ll encourage that too 😉).
Cold Exposure: Your Nervous System’s Winter Gym
When you enter cold water, your whole body goes:
“HELLO, ARE WE OKAY?!”
But the moment you breathe — really breathe — you flip the script.
Suddenly your vagus nerve wakes up like:
“Wait, we’re not dying? We’re adapting? Oh… I'm into this.”
This nerve is your personal thermostat for calm.
It decides whether you’re spiraling in stress or grounded in “I’ve got this.”
Every time you stay calm in the cold, you strengthen your vagus nerve.
Not metaphorically. Literally.
You become someone who:
• recovers faster
• handles pressure gracefully
• stays clear-headed when life gets messy
• doesn’t crumble when bad news lands
• feels emotionally stable in winter
And yes — that is one reason I don’t get winter blues.
Cold exposure = emotional resilience training.
(Also known as “why I annoyingly thrive when it gets dark at 3PM.”)
Deep Inside Your Cells: Mitochondria Are Having a Party
Let’s talk mitochondria — your cellular power plants.
The queens of energy.
The goddesses of glow.
Cold exposure does something magical:
It tells your cells to make more mitochondria.
More mitochondria =
✨ more energy
✨ better fat-burning
✨ better mood
✨ better sleep
✨ slower aging
✨ better stress resilience
In other words:
Every cold plunge is a metabolic workout.
Your cells literally get stronger.
This is why people say after a cold dip:
“OMG I feel amazing!!!”
Well yes.
Your mitochondria are basically screaming,
“WOOOO MORE ATP, BABY!!”
The Hidden Vitamin D Connection (Nobody Talks About This)
Here’s the plot twist that made me fall even more in love with winter:
Cold exposure may support your body’s Vitamin D pathways — even without sunlight.
Wait, what?!
Yes.
You always hear:
“Vitamin D = sunshine.”
But your mitochondria are light-sensitive in a much more complex way.
Cold exposure triggers:
• nitric oxide release
• cytochrome c oxidase activation
• metabolic signaling
• calcium regulation
All deeply tied to Vitamin D pathways.
In winter — especially for us living far north — UVB is almost nonexistent.
So what does nature do?
It gives us cold as a replacement stimulus.
Cold says to your biology:
“Light is gone, but stay awake.
Keep energy high.
Keep mood stable.
Keep metabolism alive.”
This is why Nordic cultures have been cold plunging long before Instagram caught on.
It’s not a trend — it’s human biology.
What Happens When You Avoid the Cold All Winter
If you stay warm, indoors, and under artificial lighting all winter:
• dopamine drops
• thyroid slows
• mitochondria downshift
• mood dips
• stress rises
• sleep gets weird
• energy tanks
And that, my love, is what we call...
The Winter Blues Starter Pack.
The Laura Hof Winter Equation
This is how I survive — no, thrive — through winter:
Less artificial warmth.
More natural cold.
Less stress reactivity.
More nervous system mastery.
Less gloom.
More mitochondria.
Less hiding.
More nature.
Winter isn’t meant to make us sad.
It's designed to make us strong.
Cold awakens you.
Light nourishes you.
Together they keep your biology alive, vibrant, and deeply human.
If you want to feel more alive this winter…
Try this:
• One cold shower at the end of your warm one
• 20–30 seconds is enough (though I’ll cheer if you go longer 😉)
• Add breath awareness: slow, soft inhale + long exhale
• Step out feeling like a mythological creature
Your mitochondria will thank you.
Your mood will thank you.
Your nervous system will thank you.
And maybe — just maybe — you’ll skip winter blues this year.
