5 Supplements & Your Smile: What the Science Really Says

Our last post about supplements covered five nutrients we commonly hear questions about when it comes to oral health. A few of you asked, “Where’s this from?” Fair question. So, we went back to the research and took a closer look at what the evidence actually shows.

Vitamin D3 (and Vitamin K2)

Vitamin D3/K2 plays an important role in calcium absorption and bone health - including the bones that support your teeth. Research has also found an association between lower vitamin D levels and periodontal (gum) disease. There is some evidence that vitamin D3/K2 supplementation may support periodontal health, particularly when combined with professional dental care, but it is not a treatment for gum disease on its own.

What this means for you: Most adults need about 600 IU of vitamin D per day (800 IU for adults over 70). The general upper limit for daily intake is 4,000 IU unless your healthcare provider recommends otherwise. If you're concerned about your vitamin D status, a blood test can help determine whether supplementation is appropriate.

Taking warfarin or another medication affected by vitamin K? Talk with your doctor before taking vitamin K2, as vitamin K can interfere with warfarin's effects.

Magnesium

We want to correct something from our last post: we overstated the evidence around magnesium and teeth grinding.

There isn't strong evidence that taking magnesium supplements prevents or treats bruxism (teeth grinding or clenching). The idea comes largely from theories about magnesium, muscle function and nervous-system activity - but that isn't the same as having clinical evidence that supplementation stops grinding.

What the research does suggest is an association between vitamin D status and bruxism, although more research is needed before we can say that vitamin D supplementation prevents grinding.

What this means for you: Magnesium is still an important nutrient and is found naturally in foods such as nuts, seeds, whole grains and leafy greens. If you're considering a supplement, speak with your healthcare provider — particularly if you have kidney disease, as excess magnesium can be harmful.

Magnesium bisglycinate is one form commonly found in supplements, but “more bioavailable” doesn't automatically mean “better for everyone.”

B Vitamins — Promising Evidence, But Not a Magic Gum Supplement

B vitamins play important roles in cell health and metabolism, and adequate folate and B-vitamin status are associated with healthier oral tissues.

Some research has found relationships between lower levels of certain B vitamins — particularly folate, B1, B2 and B6 — and poorer periodontal health. However, this doesn't mean that taking extra B vitamins will necessarily improve your gums if you're already getting enough.

The takeaway: Getting enough B vitamins through a balanced diet is important. Supplementation is most useful when there is a known deficiency or a specific reason to supplement. Methylated versions are suggested for absorption. And when it comes to B12, more expensive doesn't necessarily mean better. 

Probiotics — The Specific Strain Matters

This is where the details really matter.

Research on oral probiotics has looked at specific bacterial strains, including Streptococcus salivarius M18, rather than “probiotics” as one broad category. Some studies have found improvements in plaque and gingival health with specific strains. But the effects tend to be strain-specific, and the evidence isn't strong enough to say that probiotics generally prevent or treat gum disease.

What this means for you: If you're considering an oral probiotic, look for the specific strain and dose listed on the label rather than simply choosing a product with a large number of bacteria.

And remember: probiotic benefits may not persist after you stop taking them.

Omega-3 (Fish Oil) — A Modest Potential Benefit

Omega-3 fatty acids have anti-inflammatory properties, which makes them particularly interesting in periodontal research.

Some clinical trials have found that omega-3 supplementation, when used alongside professional periodontal treatment, may provide a modest additional benefit for gum health.

It's not a replacement for professional cleaning or periodontal treatment — but there is some evidence that it may be a useful addition in certain situations.

What this means for you: High doses of fish oil may increase bleeding risk and can interact with certain medications. If you take blood thinners or are considering a high-dose supplement, check with your healthcare provider first.

The Bottom Line

Supplements can be useful — but they're not a shortcut to better oral health.

• 🦷 Brush and clean between your teeth: still the foundation.

• 🥦 Food first: a varied, whole-food diet is the best way to get most nutrients.

• 🧪 Test when appropriate: if you're concerned about a deficiency, testing can be more useful than guessing.

• 💊 Choose supplements carefully: more isn't necessarily better, and evidence varies considerably from one nutrient to another.

• 🩺 Talk to your healthcare provider: especially if you take medications, have kidney disease, are pregnant, or are considering high-dose supplementation.

  
  

The biggest takeaway? There is interesting research connecting nutrition and oral health — but a supplement should complement good dental care, not replace it.

Want to talk through what's actually right for you? Meet the team

Sources

• NIH Office of Dietary Supplements — Vitamin D Fact Sheet for Health Professionals — https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/

• NIH Office of Dietary Supplements — Vitamin K Fact Sheet for Health Professionals — https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/

• NIH Office of Dietary Supplements — Magnesium Fact Sheet for Health Professionals — https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/

• NIH Office of Dietary Supplements — Vitamin B12 Fact Sheet for Health Professionals — https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/

• NIH Office of Dietary Supplements — Omega-3 Fatty Acids Fact Sheet for Health Professionals — https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/

• BMC Oral Health — Association of vitamin D in individuals with periodontitis: an updated systematic review and meta-analysis (2023) — https://bmcoralhealth.biomedcentral.com/articles/10.1186/s12903-023-03120-w

• Nutrients (MDPI) — The Role of Vitamin B Complex in Periodontal Disease: A Systematic Review (2025) — https://www.mdpi.com/2072-6643/17/7/1166

• Nutrients (MDPI) — Antigingivitis and Antiplaque Effects of Oral Probiotic Containing S. salivarius M18: A Randomized Clinical Trial (2023) — https://www.mdpi.com/2072-6643/15/18/3882

• Frontiers in Oral Health — Omega-3 PUFAs in the Non-Surgical Management of Periodontitis: A Systematic Review and Meta-Analysis (2026) — https://www.frontiersin.org/journals/oral-health/articles/10.3389/froh.2026.1761032/full

• PMC — Nutrient Insufficiencies and Deficiencies Involved in the Pathogenesis of Bruxism (Review) — https://pmc.ncbi.nlm.nih.gov/articles/PMC10632959/