This weekend, while everyone’s focused on Halloween candy, I’m thinking about something completely different: the sun.
October 31st marks the point in the year when much of North America, Europe, and the Northern Hemisphere loses the angle of sunlight needed to produce adequate Vitamin D.
And after 40+ years in practice, this is the seasonal shift I pay closest attention to.
Looking back through years of patient records, I noticed something: patients who came in during late winter and early spring consistently had worse periodontal health than they did in the fall. More bleeding. Greater pocket depths. More inflammation.
The research backs this up: A 2023 meta-analysis found that people with periodontitis have significantly lower vitamin D levels than healthy individuals.
Women with vitamin D below 10 ng/mL had a 5.6-fold increased risk of periodontitis.
But here’s where it gets interesting—and where most dentists still miss the connection.
The Calcium Paradox
I came across research that flipped my understanding of calcium completely upside down:
Vitamin D3 loads calcium into your bloodstream. But without Vitamin K2, that calcium has no GPS. It wanders aimlessly and deposits in your arteries, kidneys, or joints—anywhere except your bones and teeth.
K2 activates proteins like osteocalcin that direct calcium into bones and teeth while preventing arterial calcification.
You can take all the calcium and vitamin D you want, but without K2, you’re potentially making things worse.
A 52-year-old woman came to see me one winter. Meticulous about oral hygiene her entire life. Never had a cavity. Then over several months—three cavities. Receding gums. Terrified.
Her bloodwork: Vitamin D at 18 ng/mL. Taking calcium supplements but no K2.
We changed her protocol. Within several months, her gum inflammation improved dramatically. Her teeth stopped being sensitive. Her X-rays showed her bone loss had stabilized.
Conventional dentistry treats symptoms with toothbrushes when we should really be addressing systemic deficiencies.
“In terms of prevention of dental caries, optimum nutrition with fat soluble vitamins like K2 plays a far more significant role than the traditional dental recommendation to simply eat less sugar to minimize oral bacterial acids.”
—Dr. Ken Southward (source)
This Isn’t Just About Your Teeth
The combination of vitamin D deficiency and periodontitis increases the risk of type 2 diabetes more than either factor alone.
Your bleeding gums are a warning sign. The same inflammatory processes destroying bone around your teeth are linked to cardiovascular disease, diabetes, and other systemic conditions.
What I Do Starting in Fall
This is my personal winter protocol:
Take them together with a meal containing healthy fats.
But start with testing. You want vitamin D levels between 50-70 ng/mL. Research shows vitamin D supplementation as an adjunct to periodontal treatment significantly improves clinical outcomes—but you need to know your baseline.
If you’re working with a functional dentist who understands these connections, they can help optimize your protocol. Find one in my Functional Dentist Directory or through AADSM.org.
Tomorrow night, kids will come to your door holding bags full of candy.
But the real Halloween trick isn’t the sugar.
It’s that starting tomorrow (assuming you’re in the Northern Hempisphere) you’re losing the very thing your teeth, bones, heart, and brain need most—and most people have no idea.
While everyone’s worrying about cavities from candy, I want you thinking about what happens over the next four months as your vitamin D levels progressively drop.
Get tested. Supplement smartly. And if you’re already taking vitamin D without K2, you’re potentially creating a deficiency that makes things worse.
Taking high-dose vitamin D without K2 can create a functional K2 deficiency. These nutrients work as a team—don’t supplement one without the other. This is the one I take because it’s two-in-one, and rigorously tested for purity.
This is preventive medicine that actually works—because it addresses the root cause, not the symptoms.
To your health,
Mark
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Sources & Further Reading
Vitamin K2 and the Calcium Paradox: How a Little-Known Vitamin Could Save Your Life
What’s the link between vitamin D, gum health, and diabetes?
Vitamin D and Periodontitis: A Systematic Review and Meta-Analysis
A hypothetical role for vitamin K2 in the endocrine and exocrine aspects of dental caries