Why I Stopped Taking Vitamin D Supplements (and What I Do Instead)

I wanted to share with you why I stopped taking Vitamin D supplements.

I’ve always been drawn to natural ways of staying healthy, and much of my lifestyle and nutrition has been inspired by what my ancestors might have done to live long, vibrant lives. (My grandfather lived disease-free for 101 years!) I’ve also been influenced by other sources of “natural health” wisdom, many of which promoted synthetic Vitamin D supplementation.

Vitamin D used to be considered part of alternative medicine, but now it’s fully mainstream. The older I get, the more I’m inspired by nature’s order and balance and the more I stay away from anything synthetic. That’s why the research done by Morley Robbins through the Root Cause Protocol has held my attention for years—because the more I study it, the more it aligns with my values around health and healing.

What Is “Vitamin D,” Really?

Despite its name, Vitamin D is not actually a vitamin—it’s a secosteroid hormone, one of the most powerful in the body. Hormones are signaling molecules; they activate important biological processes. So calling it a “vitamin” can be misleading.

When Vitamin D is measured, it’s typically only the storage form (25-hydroxy) that’s tested, while the active form (1,25-dihydroxy) is ignored. If your storage form is low, it's often treated like a simple deficiency. But it’s far more complex than that.

Low storage Vitamin D might not mean you need more—it might mean you're stressed, inflamed, or low in magnesium. One metaphor that helped me understand this is that Vitamin D status isn’t like a gas tank that just needs to be topped off—it’s more like miles per gallon, affected by many variables like enzyme function, mineral status, and stress.

The Case for Sunlight Over Supplementation

Historically, our ancestors got Vitamin D through outdoor living and nutrient-dense diets. Our bodies can store Vitamin D in the liver for up to six months, which means we’re designed to get it from the sun.

Here’s what’s fascinating: in nature, Vitamin D always comes with Vitamin A—and Vitamin A is crucial for Vitamin D function. When sunlight hits the skin, it converts cholesterol into the precursor of Vitamin D. That precursor then travels to the liver, where it's converted into the storage form (25-hydroxy). This process is enzyme-driven—and those enzymes are magnesium-dependent.

The final step happens in the kidneys, which convert the storage form to the active form (1,25-dihydroxy). That step also relies on magnesium.

So both phases of Vitamin D synthesis also require magnesium—and magnesium is depleted by stress. That means if your Vitamin D levels are low, the root issue may be stress, low magnesium, or compromised enzyme activity. It’s not as simple as “just take a supplement.”

I used to believe that taking Vitamin D would reduce my inflammation—but I’ve learned that low Vitamin D is more likely a sign of inflammation than a cause of it. Inflammation lowers Vitamin D levels, not the other way around. If you’re stressed and low in magnesium, enzyme function is impaired, and your body can’t process Vitamin D properly.

It’s also essential to remember that Vitamin A and D work synergistically, as do all fat-soluble vitamins (A, D, E, and K). Taking high doses of one without the others can cause imbalances. A great natural source of both Vitamins A and D is cod liver oil, which has been used in traditional diets around the world.

Sunlight remains my favorite source of Vitamin D—not only because it initiates this elegant biochemical process, but because it also helps break down Vitamin A into retinoic acids, which are themselves powerful hormones that support whole-body health.

Lessons From the Root Cause Protocol

One of the most important lessons I’ve learned from the Root Cause Protocol is this: just because a blood level is low doesn’t mean you need to supplement.

It’s like with iron—low levels in the blood don’t automatically mean you're iron-deficient. The body’s internal systems are complex, and numbers on a lab report don’t tell the full story. These levels are more like feedback from a dynamic, adaptive system—not warning lights on a dashboard.

What I Do Now

I now use my weekends to soak up natural Vitamin D. Just one 15-minute sunbathing session with lots of skin exposed can give me around 1600 IUs from the sun.

I use the app D-Minder to track the best times of day for Vitamin D exposure and estimate how much I’m getting. Sitting in the sun for 15 minutes at the right time of day gave me about 1600 IUs. That’s often enough for the whole week, because our bodies were designed to store and use it efficiently.

Whenever possible, I choose nature’s way—because we were divinely designed for health, healing, and happiness. We just need to remove what’s interfering with that design.

I also take cod liver oil daily as part of my nutrition plan. It naturally contains both Vitamin D and Vitamin A. I recommend this brand (not affiliated).

Nuance, Balance & the Root Cause Protocol

The Root Cause Protocol emphasizes balance—especially the balance of minerals in the body—as the foundation of sustainable health. Their motto is “less is more” when it comes to supplements. Wherever possible, nutrients are encouraged from food.

Vitamins and minerals don’t work in isolation. They’re synergistic, and supplementing one without understanding the full picture can create imbalances and symptoms. Synthetic supplements may do more harm than good. Morley Robbins always asks, “What’s enduring? What did our ancestors do?”

This model of healing is about energy, resilience, and long-term health—not quick fixes or biohacks. It’s a lifestyle rooted in nourishment. It may take 12–18 months to see full results, but that’s what sustainable healing often looks like.

For more information, I recommend exploring the Root Cause Protocol 101 Video Series (affiliate link). Also, for you interested, here's a wonderful research article that concludes that there is no clinical benefit to a Vitamin D (25-Hydroxy D) serum level above 21 ng/mL. So maybe what nature provided is just right and we can get our Vitamin D from the sun and nutrient dense food sources.

By the way, a great bonus I get from my weekend sun bathing sessions: relaxing reading time and an elevated mood for days.

With warmth and respect,
Diana