Vitamin D, Teeth and Ageing: What the Research Shows
- , by SANUSq Research team
- 12 min reading time
Most of us link vitamin D with bones, but the vitamin D teeth connection is just as real, and it becomes more relevant as we get older. That doesn't make it a shield against tooth decay. Here is what the research actually shows, why the link grows stronger with age, and where vitamin D sits among the habits that matter most for your teeth.
The vitamin D teeth connection: how it works
The link makes sense once you know what vitamin D does. It contributes to the normal absorption and utilisation of calcium and phosphorus, the two minerals that give bones and teeth their hardness. That is why vitamin D is recognised in the EU as contributing to the maintenance of normal teeth and normal bones.
Teeth are built from mineralised tissue: hard enamel on the outside and dentine underneath. Both depend on a steady supply of calcium and phosphate. Calcium itself contributes to the maintenance of normal teeth, and vitamin D helps the body make that calcium available. When vitamin D runs low, the body handles these minerals less efficiently, much as it does in bone.
Researchers have also looked at other ways vitamin D might matter in the mouth, including its role in the body's own antimicrobial peptides and in saliva.
In a narrative review, Durá-Travé and Gallinas-Victoriano (2024) summarised the mechanisms proposed to link low vitamin D with tooth decay in children. These included enamel defects when levels are low during pregnancy, reduced activity of antibacterial peptides, lower saliva output and less calcium in saliva. These are proposed mechanisms drawn from the existing literature, not proof of cause and effect.
So vitamin D's role for teeth is not trivial. But it is one factor among several, and not the most important one.
What the research shows about tooth decay
Several lines of research point in the same direction, from childhood through to later life. The strongest data come from observational studies, which compare people with different vitamin D levels rather than testing a supplement directly.
A systematic review and meta-analysis by Li et al. (2023) pooled 13 observational studies in children. Those with vitamin D deficiency had about a 22% higher risk of tooth decay than children with normal levels. The authors concluded that low vitamin D may be a potential risk factor, not a proven cause.
Much less research has looked at older adults, which is what makes the next study useful.
Hung et al. (2024) analysed US national survey data (NHANES 2011–2016) from 2,723 adults aged 65 and over. Vitamin D deficiency was linked to a higher likelihood of untreated decay, but this link weakened and was no longer statistically clear once age, sex, ethnicity and other demographic factors were taken into account. Severe deficiency was associated with a modestly higher score for decayed, missing and filled teeth, and that association held after adjustment.
These findings are associations, often modest, and they come with an important caveat. People with low vitamin D often differ in many other ways: diet, general health, income and access to dental care. Any of these can skew the comparison.
Controlled trials of vitamin D for tooth decay do exist, but most are very old.
A systematic review by Hujoel (2013) gathered 24 controlled trials involving 2,827 children. The pooled result suggested fewer cavities with vitamin D, but 22 of the 24 trials predated modern trial design, results varied widely and there was evidence of publication bias. The author rated the conclusion as low certainty, which is why researchers continue to call for well-designed modern trials.
Vitamin D and ageing: why the link grows stronger
Two trends come together in later life. First, low vitamin D becomes more common. Older skin makes vitamin D less efficiently, and many older people spend less time outdoors.
In a classic laboratory study, MacLaughlin and Holick (1985) compared skin samples from people aged 8 to 92. When exposed to ultraviolet light, skin from people in their late seventies and eighties produced less than half the vitamin D precursor that skin from children and teenagers produced.
Second, the mouth itself changes. Gums can recede and expose the roots of teeth, which are softer than enamel and more prone to decay. Many common medicines reduce saliva, and a dry mouth is a real problem, because saliva rinses away food, neutralises acids and returns minerals to the enamel surface. The bone that holds teeth in the jaw can also thin with age.
Gum disease (periodontitis) and tooth loss are the main reasons older adults lose teeth. Studies have found observational links between these conditions and low vitamin D status.
A meta-analysis by Machado et al. (2020), mostly from case-control studies, found that blood vitamin D levels were significantly lower in people with chronic periodontitis than in people with healthy gums. There were too few studies to say whether vitamin D supplements make any difference alongside standard gum treatment.
Among 2,346 older adults in the Irish Longitudinal Study of Ageing, Winning et al. (2024) found that those with the lowest vitamin D levels were more likely to have periodontitis and fewer natural teeth than those with the highest levels, even after adjusting for other risk factors. As a cross-sectional study, it cannot show which came first.
Following 1,904 adults in Germany for five years, Zhan et al. (2014) found that higher vitamin D levels were associated with fewer teeth lost over time, with a 13% lower risk for each 10 µg/L increase. No significant association was found between vitamin D and the progression of decay.
If your gums bleed, feel sore or are pulling back, or a tooth feels loose, see a dentist. These are signs that need a professional examination, and no nutrient replaces that.
How tooth decay actually happens
To see where vitamin D fits, it helps to understand decay itself. Every time we eat, enamel goes through a tug of war. Bacteria in plaque turn sugars into acids that pull minerals out of the enamel. Saliva and fluoride then help put minerals back. As long as repair keeps pace with the acid attacks, the tooth holds. When acid wins, through frequent sugar, poor cleaning or too little saliva, a cavity develops.
Vitamin D supports the mineral side of this balance. It does nothing about sugar or plaque bacteria, which is why the basics matter so much more.
Dental care basics come first
Tooth decay and gum disease have many causes, and no single nutrient changes the core equation. The best-established habits for keeping teeth and gums healthy are:
- Brushing twice a day with a fluoride toothpaste, spitting rather than rinsing afterwards.
- Cleaning between your teeth once a day with floss or interdental brushes.
- Cutting down on sugary foods and drinks, especially snacking and sipping between meals.
- Regular dental check-ups, so problems are picked up early.
- Asking about dry mouth if you take regular medicines; your dentist or pharmacist can suggest ways to manage it.
- Not smoking, which is one of the strongest risk factors for gum disease.
A cavity that has already formed needs dental treatment, sometimes a filling. Vitamin D won't repair it.
Vitamin D deficiency and teeth: keeping your levels where they should be
The goal is not to take vitamin D "for your teeth" but to avoid running short of it. Three sources work together:
- Sunlight. Short, regular periods outdoors allow your skin to make vitamin D, without letting it burn.
- Food. Oily fish such as salmon, herring and sardines, egg yolks and fortified foods provide a modest amount.
- Testing and supplements. If you are older, spend little time outside or live somewhere with dark winters, ask your doctor about a blood test. A supplement at the dose on the label, or the one your doctor suggests, can then fill a gap.
More is not better. Vitamin D is a fat-soluble vitamin, and taking high doses for a long time without medical supervision can cause harm. Aim for adequate levels rather than loading up.
Vitamin D is often combined with vitamin K2. Vitamin K contributes to the maintenance of normal bones and to normal blood clotting. If you take a blood thinner such as warfarin, speak to your doctor before starting any product that contains vitamin K, because it can affect how the medicine works.
The bottom line
Vitamin D contributes to the maintenance of normal teeth and normal bones, and observational studies link low vitamin D with more tooth decay, gum disease and tooth loss, particularly in later life. That is a sensible reason not to let your levels slip as you age. But fluoride toothpaste, daily cleaning between teeth, less sugar and regular dental visits remain the foundation, with vitamin D in a supporting role.
Frequently asked questions
Can vitamin D deficiency affect your teeth?
Vitamin D contributes to the maintenance of normal teeth, and studies have linked low levels with more tooth decay in children and with more decayed, missing and filled teeth in older adults. These are associations, and many other factors play a part.
Does vitamin D stop cavities?
Not on its own. Old trials hinted at fewer cavities, but the evidence is low certainty. Fluoride toothpaste, cleaning between teeth and limiting sugar remain the main ways to protect your teeth.
Can vitamin D repair a cavity?
No. Once a cavity has formed it needs dental treatment. Vitamin D supports the mineral balance of teeth in general; it does not repair existing damage.
Is vitamin D linked to gum disease?
Studies have found lower vitamin D levels in people with gum disease and a link with tooth loss in older adults, but they don't prove that low vitamin D causes it. If your gums bleed or recede, see your dentist.
Why are older adults more affected?
Low vitamin D is more common with age, because the skin makes less of it and people often get less sun. At the same time, dry mouth, receding gums and exposed roots make teeth more vulnerable.
Why is vitamin K2 often combined with vitamin D3?
Vitamin K contributes to the maintenance of normal bones, so it is often paired with vitamin D3. If you take an anticoagulant such as warfarin, check with your doctor first, as vitamin K can interfere with it.
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References
- Durá-Travé T, Gallinas-Victoriano F. Dental caries in children and vitamin D deficiency: a narrative review. European Journal of Pediatrics. 2024;183(2):523–528. PMID 37966493
- Li Z, Wei X, Shao Z, Liu H, Bai S. Correlation between vitamin D levels in serum and the risk of dental caries in children: a systematic review and meta-analysis. BMC Oral Health. 2023;23(1):768. PMID 37858104
- Hung M, Mohajeri A, Sadri M, Khodabandeh E, Zeitoun I, Lipsky MS. The association of vitamin D levels and dental caries in older adults: a cross-sectional study. Nutrients. 2024;16(14):2307. PMID 39064749
- Hujoel PP. Vitamin D and dental caries in controlled clinical trials: systematic review and meta-analysis. Nutrition Reviews. 2013;71(2):88–97. PMID 23356636
- MacLaughlin J, Holick MF. Aging decreases the capacity of human skin to produce vitamin D3. Journal of Clinical Investigation. 1985;76(4):1536–1538. PMID 2997282
- Machado V, Lobo S, Proença L, Mendes JJ, Botelho J. Vitamin D and periodontitis: a systematic review and meta-analysis. Nutrients. 2020;12(8):2177. PMID 32708032
- Winning L, Scarlett S, Crowe M, O'Sullivan M, Kenny RA, O'Connell B. Vitamin D, periodontitis and tooth loss in older Irish adults. British Journal of Nutrition. 2024;132(4):503–511. PMID 39290089
- Zhan Y, Samietz S, Holtfreter B, et al. Prospective study of serum 25-hydroxy vitamin D and tooth loss. Journal of Dental Research. 2014;93(7):639–644. PMID 24828383
Read more on the blog
- Bone and Joint Wellness in the Elderly →
- How to Prevent Gum Disease →
- Vitamin K2 (and D3): The Key to Where Your Calcium Goes →
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The team at SANUSq.
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