4 Out of 7 of Us Were Low in This One Lab: Why Vitamin D might be the missing piece you didn’t know to look for
We ran labs on our team recently. The results stopped us.
Four out of seven of us had Vitamin D levels in the 20s.
20s is not where you want to be. Most labs flag insufficiency well above that, and the level where people start to feel good tends to sit higher still.
Our staff is health-conscious. We work in wellness. We talk about prevention, hormones, skin, and energy every day. If more than half of us were low, how many other people are walking around feeling off without knowing Vitamin D could be part of the picture?
Cleveland Clinic reports about 35% of US adults are deficient. Globally, another 50% sit in the insufficient range. This isn’t a rare lab finding. It’s one of the most common nutrient gaps we see, including in people who otherwise feel fine.
What low Vitamin D actually looks like
Vitamin D shows up in more places than bone health. It plays a role in immune function, mood, energy, muscle function, and cellular health.
When it’s low, the symptoms aren’t always dramatic. They tend to look like this:
- Fatigue that doesn’t match how much you slept
- Brain fog
- Low or flat mood
- Muscle aches or weakness
- Catching every bug going around
You can also be deficient with no symptoms at all. That’s directly from Cleveland Clinic’s clinical guidance. Feeling fine isn’t proof your levels are fine.
The hair loss connection
One symptom worth pulling out: hair thinning.
A 2025 study comparing women experiencing hair loss to a control group found the hair-loss group averaged Vitamin D levels around 26 ng/dL. The control group averaged 32. Vitamin D receptors sit directly inside your hair follicles — when levels drop, follicle cycling gets disrupted, and shedding can follow.
For women in their late 30s and 40s, hair changes get blamed on hormones almost reflexively. Hormones are usually part of it. But the nutrient piece is testable and correctable, and it’s often the simpler place to start.
The GLP-1 connection
If you’re on a GLP-1 medication — or considering one — there’s something worth knowing about Vitamin D.
It’s a fat-soluble vitamin. In patients with a BMI over 30, fat cells sequester Vitamin D and keep it from circulating, which is part of why higher doses are often needed to reach normal levels. The same principle matters during rapid weight loss: when fat composition is actively changing, absorption and circulation patterns are too.
This is one of the reasons we run a foundational lab panel before, during, and after weight management protocols. Vitamin D is one of the markers we watch.
Why formulation matters
ADK pairs three fat-soluble vitamins your body uses together:
- Vitamin D3 — supports immune function, mood, energy, bone health, and overall wellness
- Vitamin K2 — helps support healthy calcium metabolism and guides calcium toward bone
- Vitamin A — supports immune health, skin, and cellular function
Two pieces of this formulation matter clinically.
First, the D3. Vitamin D comes in two forms — D2 (ergocalciferol) and D3 (cholecalciferol). D3 is the form your body absorbs more efficiently. ADK uses D3.
Second, the K2. Most D3-only supplements skip K2 entirely, which means calcium gets mobilized but isn’t always directed where it belongs. K2 takes care of that piece of the equation.
That’s why we chose this formulation specifically.
Don’t guess — test
Supplementing blindly isn’t smart, especially with fat-soluble vitamins. Your body stores what it doesn’t use, and Vitamin D toxicity is real — Cleveland Clinic flags that excess Vitamin D can drive blood calcium too high, causing nausea, confusion, and weakness.
That’s why we built our Wellness Consult + Lab Review around this exact question. We look at your numbers, your symptoms, and your goals, and we make decisions from there.
→ [Book your Wellness Consult + Lab Review]
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