Why Your Vitamin D Is Still Low (Even If You’re Taking It)
By Sadie, NP — Functional Primary Care at FunctNP Functional Medicine/ Idaho Functional Care
Vitamin D is one of the most commonly checked labs in primary care — and one of the most commonly low. Most people assume low vitamin D means one thing:
“You’re not taking enough.”
But that’s not the full story.
As a functional primary care provider, I routinely see people who do supplement with vitamin D… and their levels are still low.
Here’s why — and what your labs may actually be trying to tell you.
What Vitamin D Actually Does
Vitamin D isn’t just a “bone health” vitamin. It functions more like a regulatory hormone, affecting:
Immune balance
Inflammation control
Mood and energy
Nervous system support
Hormone regulation
Muscle recovery
Your body uses vitamin D constantly — and sometimes, faster than you can replenish it.
Symptoms of Low Vitamin D
People may experience:
Fatigue
Low mood
Musculoskeletal aches
Frequent colds or slow recovery
Poor stress tolerance
Increased inflammation markers
But the real key is why the level is low — not just that it’s low.
Why Vitamin D Stays Low Even When You Supplement
1. Your Body Is Using It Faster Than You’re Taking It
This is the part almost nobody talks about:
Vitamin D levels reflect demand — not just intake.
If your immune system is activated or you have low-grade inflammation, your body uses vitamin D at a significantly higher rate. Vitamin D helps regulate inflammatory pathways, so in an inflamed state, it gets burned through quickly.
This is why your labs can show:
Low vitamin D
Elevated CRP, ESR, or immune-driven patterns on CBC
…even when you’re taking supplements consistently.
2. Low-Grade Inflammation Often Goes Undetected
You do not need to feel “sick” to have inflammation.
It can come from:
Metabolic dysfunction
Chronic stress
Viral aftermath
Autoimmune activation
Musculoskeletal pain
Gut or food-related inflammation
Vitamin D is a major player in calming these pathways.
When those pathways are active → Vitamin D drops.
3. Most Primary Care Doesn’t Connect the Dots
In traditional primary care, vitamin D is treated as:
Low = take more.
But functional primary care asks a better question:
Why is your body using so much vitamin D in the first place?
By looking at:
Vitamin D
CRP
ESR
CBC with differential
Symptoms
Immune patterns
…we can identify the real driver of the drop.
Functional Primary Care Helps You Understand the “Why”
At FunctNP Functional Medicine, we don’t rely on expensive specialty testing to understand your vitamin D story.
We start with simple, insurance-covered labs and interpret them through a functional lens.
Because when you understand the story behind your labs, you can actually fix the problem — not just treat the number.
What You Can Do If Your Vitamin D Is Still Low
✔ Check for inflammation
Even mild elevations in CRP or ESR matter.
✔ Look for immune activation patterns
Neutrophils, lymphocytes, eosinophils — all tell a story.
✔ Support your body’s demand
Supplementation is still important, but the amount you need depends on what your body is fighting.
✔ Find and address the source
This is where functional primary care makes the difference.
The Bottom Line
If your vitamin D levels are persistently low, it may not mean you’re “not taking enough.”
It may mean your body is using more than you’re replenishing — a clue worth paying attention to.
Vitamin D is dynamic, not static.
Once you identify what’s increasing demand, your levels improve… and so does how you feel.
FDA To Remove Black Box Warning for HRT. Advancing Women’s Health.
Recently, the FDA announced plans to remove black box warnings from HRT replacement therapy for women: estrogen/progestin. This black box label has been in place since 2003 after a research study published by the Women’s Health Initiative (WHI) indicated increased risk for breast cancer, cardiovascular events and stroke among women receiving combined HRT.
However, the WHI study faced significant critique. Researchers and clinicians have identified several flaws and limitations, those of which included: age of participants, timing of therapy initiation, types and routes of hormone formulations used and baseline health status.Despite these limitations, the WHI findings became the foundation for decades of restrictive guidance on hormone therapy. These variables are critical to consider before generalizing outcomes to all women.
It’s also important to remember that hormone replacement therapy extends beyond symptom management. Estrogen acts as a powerful neurosteroid, supporting brain health and cognitive function (women are nearly twice as likely as men to develop Alzheimer’s disease). It also helps preserve bone density, which declines sharply after menopause, and protects cardiovascular health by maintaining vascular flexibility and lipid balance.
Functional practitioners have long understood the benefits of HRT replacement for women beyond just managing hot flashes but to preserve heart bone health to enhance longevity.
It is both refreshing and exciting to see that reflection in the broader healthcare landscape. I am looking forward to publications in the future that support the health benefits HRT replacement for women that we have known.
The Most Overlooked Factor in Your Health: The Patient–Provider Relationship
When we think about improving our health, we often focus on what to do: eating better, taking supplements, exercising more. But one of the most powerful, and often overlooked, influences on your long-term health is the relationship you have with your provider.
Why the Patient–Provider Relationship Matters
Your provider isn’t just someone who orders labs or manages medications. They’re the person helping you understand your body’s story, past, present, and future.
A strong patient–provider relationship builds trust, consistency, and communication: three pillars that directly impact your ability to prevent disease and sustain long-term wellness. When you trust your provider, you’re more likely to share what’s really happening in your life, follow through on care plans, and feel empowered in your own health decisions.
Research has shown that this relationship directly influences outcomes:
A 2017 review in PLOS One found that patients who experienced greater empathy and communication from their clinicians reported better symptom improvement and higher quality-of-life scores across a range of chronic conditions.
Similarly, research published in JAMA Internal Medicine found that patients who trusted their providers demonstrated better blood pressure control, improved diabetes outcomes, and greater adherence to treatment plans.
In other words, the relationship itself has measurable effects on physical health.
In many traditional care models, time is limited and visits are brief. That means this critical relationship often never has the chance to form. But when you have space to be heard, to ask questions, and to feel understood the quality of your care changes entirely.
How Functional Primary Care Restores That Connection
At FunctNP, functional primary care is designed to bring the relationship back to the center of medicine.
It’s healthcare that slows down, allowing time to explore your family history, patterns, and underlying causes, not just symptoms.
Functional primary care connects the dots between systems, giving context to your labs and insight into how your environment, nutrition, hormones, and stress all play a role. Most importantly, it gives space for the provider–patient relationship to thrive.
Because when we have time to listen, we can do more than react to problems, we can prevent them.
The Relationship Is the Medicine
True healing begins in partnership. It happens when your provider knows your story and walks alongside you: guiding, educating, and adjusting your care as life evolves.
At FunctNP, we believe that connection is what creates sustainable health outcomes and lasting change.
It’s not just functional medicine. It’s functional primary care, a model built on trust, prevention, and collaboration.
If You’re Ready for Care That Feels Different
Schedule your visit here to experience a new kind of primary care , one where the relationship is the foundation of your health.
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References:
Howick J, et al. “Effects of Empathic and Positive Communication in Healthcare Consultations: A Systematic Review and Meta-Analysis.” PLOS One, 2017;12(10):e0186441.
Birkhäuer J, et al. “Trust in the Health Care Professional and Health Outcome: A Meta-Analysis.” JAMA Internal Medicine, 2017;177(5):727–735.
Functional Medicine + Primary Care: How an Insurance-Based Model Can Shape the Future of Healthcare.
It all begins with an idea.
Primary care is often considered entry level healthcare and centers around preventive health screenings, management and prevention of acute & chronic diseases. Primary care as a concept is the foundation of health for the general population. An efficient primary care model would yield optimal health outcomes and lower prevalence of disease for the population in which it serves.
Except it hasn’t.
In fact, preventable death is on the rise in America and until we address our primary care model, the trend will only continue.
There are several theories as to why this downward health trend is becoming a mainstay in America’s health culture: Increased sedentary lifestyles, diet, stress, fragmented patient-provider relationships, medical mistrust, and the influence of “big pharma”, the list goes on…
As health trends continue to decline, public interest in “alternative medicine” has surged.
Alongside this, the field of functional medicine has grown in response.
More functional providers are offering root-cause treatments for ailments that traditional providers may have “missed” or quite honestly, lacked the time to address.
Functional medicine offers deeper insight into health through advanced lab testing, supplements over prescription medication, and, perhaps most importantly, time. Time to listen to your health story and time to put all of the clues together.
But what if functional medicine didn’t have to exist outside of the system to do that kind of work?
Because if we’re being honest,
Functional Medicine can actually certainly exist inside a primary care model.
Functional primary care combines the depth and lens of a functional medicine approach with the foundation of primary care. Because changing a flawed healthcare model to improve outcomes means working within to identify and address its gaps.
It reminds me of the saying “nothing changes unless you do” .
To truly move healthcare forward, we must be willing to question insurance “norms,” patient expectations, and traditional healthcare.
By doing so, we influence positive change to a healthcare model that no longer meets the needs of our health.
Ready to experience functional primary care? Book a visit.