No Evidence that Vitamin D Causally Prevents Tooth Loss.

Objectives: A recent prospective study showed that participants with elevated vitamin D levels at baseline are at lower risk of tooth loss over a five year period, implying that vitamin D might be a modifiable protective factor for tooth loss. We aimed to examine whether genetically altered vitamin D levels influenced odds of tooth loss in an adult population using a technique termed Mendelian randomization, which uses naturally occurring genetic variation to make causal inference.
Methods: We identified 8 single nucleotide polymorphisms (SNPs) which alter serum vitamin D levels in a genome-wide meta-analysis of 42,274 individuals. We investigated the relationship between genetically determined vitamin D levels and denture wearing (as a proxy for tooth loss) in 146,341 adults in the UK Biobank study (aged 40-73 years) with genotype and outcome data available. Effect estimates from each of these 8 SNPs were combined in an inverse variance weighted meta-analysis to quantify the overall causal effect of serum vitamin D levels on tooth loss. Analysis was performed using the TwoSample MR R package.
Results: There was no evidence to suggest that vitamin D was protective against tooth loss (odds ratio 1.004 per 1 standard deviation increase in log transformed vitamin D, (95% CI: 0.995:1.013)).
Conclusions: Mendelian randomization is more robust to confounding and reverse causality than conventional epidemiological methods and generally yields unbiased causal estimates .The results of this study do not support a causal role of vitamin D in preventing tooth loss in middle aged and older adults. This study may be limited by use of denture wearing as a non-specific endpoint of dental disease. Follow up analysis is planned to examine the effects of vitamin D against a panel of clinically assessed caries traits in both adults and children.