Teeth grinding/clenching (bruxism) in 40% of children and 30% of adults (low Vitamin D)
Most of this page was authored by Claude AI April 2026
Sleep Bruxism 6X more likely if low vitamin D
Yes — the observational evidence points fairly consistently in that direction, though it's all cross-sectional and no interventional trial has yet demonstrated that correcting deficiency reverses bruxism. Quick summary of what's actually been published:
The two key case-control studies
Alkhatatbeh et al. (BMC Oral Health, 2021, Jordan, n=100) compared 50 adults with self-reported sleep bruxism to 50 matched controls. Sleep bruxism carried an odds ratio of 6.66 for vitamin D deficiency, 5.94 for low dietary calcium intake (<323 mg/day), and 9.24 for frequent headache. They also found that anxiety was independently associated with lower 25(OH)D (p=0.03), depression, and female sex — consistent with the hypothesis that vitamin D's bruxism link runs partly through the anxiety/sleep-disturbance axis rather than being purely musculoskeletal.
Allaf et al. (Clinical and Experimental Dental Research, 2022, n=100) looked specifically at severity. Participants with moderate-to-severe bruxism were disproportionately those with deficient 25(OH)D levels, and the authors concluded bruxism activity was associated with 25(OH)D deficiency. That's a dose-response signal, which strengthens the case beyond a simple dichotomous association.
Mechanistic plausibility
Three mechanism lanes, all of which you already know from adjacent VitaminDWiki territory:
Central/sleep regulation. Gominak and Stumpf's hypothesis — VDR expression in brainstem nuclei involved in sleep-wake regulation — is explicitly invoked in the bruxism literature. Researchers have hypothesized that the sleep-disorder epidemic tracks widespread vitamin D deficiency because brain regions of sleep-awake regulation contain vitamin D target neurons in the diencephalon and brainstem nuclei.
Neuromuscular excitability. Low vitamin D plus low calcium plus low magnesium → increased neuromuscular excitability and masseter hyperactivity. The 2023 Spandidos review frames this explicitly, arguing that deficiencies of vitamin D, magnesium, and omega-3 fatty acids increase stress sensitivity and neuromuscular excitability, impairing the ability to buffer sympathetic overactivation.
Anxiety/pain pathway. Vitamin D → mood → bruxism via the well-established stress trigger. The Jordan study's mediation pattern supports this.
Adjacent evidence worth citing on a page
- A systematic review/meta-analysis found 25(OH)D levels significantly lower in TMD patients vs. controls (low certainty of evidence), with the Middle East vs. Europe subgroup difference being statistically significant. TMD and bruxism overlap heavily, so this is corroborating.
- A 2025 narrative review in CME Journal Geriatric Medicine on "supplements for bruxism" pulls together vitamin D, magnesium, and omega-3 as the main candidates — suggesting the clinical community is beginning to frame this as a nutrient-deficiency phenotype rather than pure psychogenic parafunction.
- The Toyama et al. 2023 paper (J Clin Med) on "Nutrients Associated with Sleep Bruxism" is worth pulling for your page — I didn't retrieve the specifics but it's cited across this literature.
Honest evidence-quality assessment
The weaknesses are the usual ones: small samples (n=100 each), self-reported bruxism in the larger study (polysomnography is the gold standard), cross-sectional design, and no RCT yet testing whether D3 repletion reduces bruxism episodes or masseter EMG activity. The ORs are large enough (6.66, and severity gradient in the second study) that confounding alone is unlikely to explain them — but residual confounding via general health, outdoor activity, and sleep quality remains plausible.
Page-building suggestion
If you're drafting a VitaminDWiki entry, the most defensible framing is "sleep bruxism is strongly associated with vitamin D deficiency in observational studies, with a plausible tri-mechanism (sleep-regulation VDR, neuromuscular excitability, anxiety mediation), but no RCT yet." The calcium and magnesium co-deficiency angle is important — the Jordan study showed calcium was a near-equally strong predictor, and magnesium is the standard bruxism supplement in naturopathic circles already. A co-factor framing fits your site's general thesis better than a D-alone framing.
Here are the headline numbers, mostly from the Zieliński et al. 2024 global meta-analysis (J Clin Med 13:4259), which is the most recent and comprehensive source.
Sleep bruxism - Adults 10% to 40%
Sleep bruxism: ~21% globally by self-report, but 43% when restricted to polysomnography studies — the gold-standard instrumented rate is roughly double the self-report rate because most grinders don't know they're doing it. Older Manfredini 2013 review put sleep bruxism at ~12.8%. A 2025 Scientific Reports paper cites the adult sleep bruxism range as 10.0% to 16.0%, which reflects the self-report literature.
Awake bruxism (clenching during the day): ~23% globally. Among adult females it was 18%, and among males 9% — a ~2:1 female skew. A separate 2023 ScienceDirect meta-analysis found possible awake bruxism prevalence of 32% in convenience samples and 16% in population-based samples, with the population-based figure being the more trustworthy one.
Combined (sleep + awake): 22.22% globally — roughly 1 in 4-5 adults.
Sleep bruxism - Children 3% to 40%
Sleep bruxism in children globally: 31.16% per the Soares et al. meta-analysis — notably higher than adults. Brazilian-specific data (Ferrari-Piloni) showed 25.8% for sleep and awake bruxism combined in children.
However, the range across studies is huge: 3.5% to 40.6% in children, depending on age band and assessment method. One systematic review noted the heterogeneity was so high that reliable point estimates for children are difficult to pin down.
Takeaway numbers for a VitaminDWiki page
- Adults: ~20% self-report sleep bruxism; ~40% when measured by PSG; ~20% awake bruxism
- Children: ~30% sleep bruxism (but high variability, 3%-40% range)
- Female:male ratio ~2:1 for awake bruxism; some sources cite 5:1
The PSG-vs-self-report gap (43% vs 21%) is probably the most important single fact — it implies the true burden is much larger than self-report captures, which strengthens the public-health case for considering vitamin D/magnesium/calcium deficiencies as modifiable contributors even when patients are asymptomatic.