There was a time I recommended vitamin D to nearly every patient who walked through my door.

Low levels. High doses. Recheck labs. Repeat.

It was the protocol everyone followed. Conventional and alternative doctors alike.

But something kept bothering me.

People were taking 5,000… 10,000 IU daily. Their blood levels were climbing. And they still had heart disease. Still had inflammation. Still felt exhausted and broken down.

So I stopped following the protocol and started asking a better question.

What if we’ve been wrong about vitamin D from the beginning?

Vitamin D Is Not a Vitamin

Let’s start with the most important thing most doctors never tell you.

Vitamin D is a hormone.

Specifically, it’s a secosteroid hormone, in the same class as testosterone and cortisol. Your body produces it when sunlight hits your skin, triggering a cascade that runs through your liver, your kidneys, and your immune system.

This is not passive. This is a highly regulated biological system.

And you cannot replace a biological system with a capsule.

When your body makes vitamin D from the sun, it produces a coordinated symphony of compounds that work together in perfect balance.

The supplement you buy gives you one isolated molecule.

That is not the same thing.

Vitamin D Supplements Are Not the Same as Sunlight or Food

This is where the conversation gets uncomfortable.

Vitamin D from a capsule is not the same as vitamin D your body makes from sunlight. And it’s not the same as vitamin D found in real, whole animal foods.

Not even close.

When your skin is exposed to sunlight, your body doesn’t just “make vitamin D.” It creates a full biological response involving cholesterol conversion, sulfate production, nitric oxide release, immune signaling, and circadian rhythm regulation.

Your body controls how much is made, when it is activated, and when it stops.

It is intelligent. It is self-regulating. It is precise.

A supplement bypasses all of that.

You swallow a lab-made molecule that artificially raises blood levels without the natural checks and balances your body depends on.

That’s not replacement.

That’s interference.

And when you interfere with biology, there are consequences.

Supplemental vitamin D can elevate blood levels while disrupting calcium metabolism, immune signaling, and vascular health, especially when taken without magnesium, vitamin K2, and the full nutrient matrix found in real food.

As a cardiologist, that matters.

Because when calcium is mismanaged, it doesn’t stay in the bones.

It ends up in the arteries.

And that’s how you accelerate cardiovascular disease while thinking you’re doing something healthy.

Even worse, supplements create a false sense of security.

People take a pill and think they’re covered, while avoiding the sun, eating processed food, and living disconnected from the very inputs that actually create health.

You cannot hack sunlight with a capsule.

You cannot replace real food with fortification.

And you cannot shortcut biology.

Why “Your Level Is Low, Take More” Is the Wrong Approach

The conventional model treats vitamin D like a gas tank.

Level is low? Fill it up.

But vitamin D doesn’t work like that.

Your blood level is just one data point. What matters is how your body produces it, activates it, transports it, and uses it at the cellular level.

Vitamin D receptors exist in nearly every cell in your body. It impacts bone health, immune function, cardiovascular health, hormone balance, brain function, and gene expression.

That level of complexity cannot be reduced to a single number on a lab report.

And pushing that number higher with supplements does not fix the underlying issue.

The Two Sources Your Body Was Designed For

Forget the supplements. Forget fortified foods.

There are only two real sources your body was designed to rely on.

Sunlight

When UVB rays hit your skin, your body converts cholesterol into vitamin D3 in a self-regulated process.

No overdose. No imbalance. No guesswork.

But sunlight does far more than make vitamin D.

It releases nitric oxide to relax blood vessels. It regulates circadian rhythm. It improves sleep. It enhances mitochondrial function. It supports immune balance and mental health.

You don’t get any of that from a pill.

Get outside daily. Midday sun. Skin exposed. No burning.

This is how humans were designed to live.

Animal foods

The second source is real, whole, nutrient-dense animal foods.

Wild salmon. Sardines. Salmon roe. Pasture-raised egg yolks. Grass-fed meats and organs.

These foods provide vitamin D in its natural form, along with the cofactors your body needs to properly utilize it.

This is a complete nutrient package.

Not an isolated chemical.

That’s why food works.

A Word on Fortified Foods

Walk through the grocery store and you’ll see vitamin D added to milk, cereal, orange juice, and processed products.

This is not nutrition.

This is marketing.

Synthetic vitamin D added to ultra-processed food does not improve your health.

You cannot fortify your way out of a bad diet.

Real food is not fortified.

Real food is complete.

What If You Don’t Get Sunlight for D?

In short, MOVE!

And if you can’t move, take a lot of vacations to sunny climates.

Stack up that summer sunshine to your solar panel, aka skin.

And if you can’t take sunny vacations, eat plenty of animal foods, especially in the winter.

Instead of Lab Supplements, Take This

Eat the animal foods and seafood.

Consider supplements like our Wild Salmon Roe and Kickstart My Heart.

The Bottom Line

I didn’t stop recommending vitamin D because it’s unimportant.

I stopped because I realized we were asking the wrong question.

The question was never how do we raise this number.

The question is why is the body out of balance, and how do we restore it?

Sunlight and real food have supported human health for thousands of years.

The supplement industry is new.

I know which one I trust.