To Fluoride or Not to Fluoride? Your Thyroid & Whole-Body Perspective
- Khristina Maureen
- Jun 28
- 4 min read
Updated: Nov 8
As a Registered Dental Hygienist for nearly two decades —and now a Certified Functional Nutrition Counselor —I don't get asked about fluoride daily. But I’ve watched it handed out like candy in the dental world for years.
Got a cavity? Use this fluoride toothpaste.
Sensitive teeth? Try this high-fluoride formula.
High cavity risk? Here’s a prescription-strength paste.
Low saliva? Protect your teeth with fluoride.
I followed this same protocol for years because that’s what we were taught in school.
Fluoride was the gold standard, and yes, it can have its place for the right person at the right time.
This isn’t about fear.
It’s about understanding the broader context behind fluoride, so you and your dental provider can make an informed choice about what’s best for you.
Fluoride & The Thyroid: What’s the Big Deal?
Fluoride doesn’t just stay on your teeth; some is absorbed by your body, especially if you swallow it or get it through drinking water. That’s where things get interesting for anyone with a thyroid condition like Hashimoto’s or an iodine deficiency.
Here’s what the research shows:
High levels of fluoride exposure can interfere with iodine utilization, which your thyroid requires to produce hormones that regulate energy, metabolism, and other bodily functions (PubMed).
Historically, fluoride has been used to help suppress an overactive thyroid (hyperthyroidism) because it can lower T3 and T4 hormone levels (Thyroid Pharmacist).
Some studies have found fluoridated water linked to higher rates of hypothyroidism, especially in communities with low iodine intake (JECH).
This effect is more pronounced when iodine levels are low, so if your intake is already borderline, your total fluoride load may be more significant (JECH).
But What About Fluoride Toothpaste?
Here’s the nuance:
A standard pea-sized dab of fluoride toothpaste that you spit out is unlikely to have any meaningful effect on your thyroid for most healthy adults.
However, some people use high-fluoride prescription pastes (like Clinpro 5000 or Prevident 5000) every single day for years. Add fluoridated drinking water, in-office fluoride treatments, the occasional accidental swallow, and total fluoride exposure, and they can start to add up.
That’s why some clinicians recommend not rinsing after brushing with prescription fluoride. It leaves a protective fluoride layer on the teeth overnight, which can be beneficial in high-risk cases.
I fully support that approach when it’s needed. However, if someone has been experiencing these issues for years without addressing the underlying causes, such as weak enamel, recurring cavities, or low saliva flow, then it may be time to look deeper.
Why Iodine Matters for the Thyroid
Your thyroid requires iodine to produce hormones that regulate various bodily functions, including energy, weight, digestion, and brain function.
Without enough iodine:
✔ You may feel exhausted, gain weight, get cold easily, or feel foggy.
✔ Your risk of hypothyroidism or goiter goes up.
✔ Fertility, heart health, and immunity can take a hit too.
Since fluoride can compete for the same pathways, it’s worth knowing your iodine status, especially if you have Hashimoto’s.
Where to Get Iodine Naturally
Natural iodine is found in seaweed, wild fish, shellfish, eggs, dairy products, and iodized salt.
However, more isn’t always better - too much iodine can also stress a sensitive thyroid; balance matters.
Long-Term Fluoride Use: What No One Talks About
Over the years, I’ve met patients faithfully brushing with prescription fluoride for years - yet they still notice:
✔ Yellowing or dull teeth
✔ Enamel that looks weaker
✔ Little change in cavity risk, despite doing everything “right”
That made me ask: Are there more innovative ways to strengthen teeth without relying on high-dose fluoride forever? Short answer? Yes.
A Functional Approach (Because Cavities Don’t Happen in a Vacuum)
Instead of stronger pastes alone, I look at the why:
Health history (thyroid, gut, autoimmunity)
Oral pH (acidic mouth? Bacteria thrive)
Mouth breathing (big dry-mouth culprit)
Gut health (affects mineral absorption → enamel strength)
Saliva (your natural cavity-fighter)
Diet (processed foods + sugar = decay)
Daily hygiene (even the best paste can’t fix plaque that's left undisturbed)
Better Basics Matter
✔ Brush well - technique beats the brand
✔ Clean between teeth (floss, water flosser, interdental brushes)
✔ Clean your tongue - bacteria love it
✔ Stay hydrated - saliva = enamel protection
✔ Eat fibrous foods - nature’s toothbrush
Hydroxyapatite: My Favorite Alternative
One fluoride-free tool I trust? Hydroxyapatite toothpaste.
It’s biomimetic, safe, and research-backed:
A 10% hydroxyapatite toothpaste worked as well as a 500 ppm fluoride toothpaste for remineralizing early enamel (BDJ Open).
A Polish clinical trial found that fluoride-free hydroxyapatite toothpaste was comparable to a standard fluoride toothpaste in cavity prevention (Frontiers in Public Health).
Frontiers in Dental Medicine review calls hydroxyapatite an effective, safe daily option (Frontiers).
My Take: Over 12 Years Fluoride-Free
I haven’t used fluoride toothpaste in over a decade, and my teeth are healthy. However, I don’t rely solely on toothpaste.
I make sure to:
✔ Eat nutrient-dense, mineral-rich foods
✔ Keep calcium, magnesium, D3 + K2, and phosphorus in check
✔ Support my gut for mineral absorption
✔ Stay hydrated & chew fibrous foods
✔ Pay attention to my oral microbiome
Real Talk & Final Bite
Fluoride can help - for the right person, at the right time. But it’s not the only tool we have.
If you have a thyroid issue, low iodine, or you’re using high-fluoride paste for years with little progress, it’s smart to ask: Why?
Root-cause questions change everything. I’m here to help you view your oral health in a broader, interconnected way. Always talk with your dental or medical provider before making changes. My goal is to help you ask better questions, not replace personalized care.
-Khristina Maureen
Your Functional Nutrition Ally
Fluoride is a tool, but not the whole story.
Ready to see your mouth through a root-cause lens?
✔️ Take my free Mouth-Body Connection Quiz
✔️ Explore my Health Root Reboot
✔️ Check out my trusted fluoride-free toothpaste picks in my supplement dispensary.
Small shifts, real results - let’s start here.
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