Influence of Vitamin D Levels on Oral Lichen Planus: A Meta-Analysis

Background: Oral lichen planus (OLP) is a chronic inflammatory mucocutaneous disease of autoimmune nature. Low serum vitamin D levels have been associated with an exaggerated inflammatory response in OLP.

Objective: To assess the influence of vitamin D levels in OLP.

Search and selection methods: A search for studies on vitamin D and oral lichen planus was performed in the following databases: PubMed (MEDLINE, Cochrane Library), Web of Science (WoS) and Scopus.

Data analysis: For continuous outcomes, the estimates of effects of an intervention were expressed as mean differences (MD) using the inverse variance (IV) method, and for dichotomous outcomes, the estimates of effects of an intervention were expressed as odds ratios (OR) using Mantel-Haenszel (M-H) method, both with 95% confidence intervals.

Results: 16 studies with 1405 participants (727 OLP patients and 678 controls) were included in this meta-analysis. OLP patients had significantly lower mean vitamin D concentrations (p<0.001) and an increased risk (OR:2.45) of having deficient vitamin D levels (p<0.01) compared to controls. In contrast, controls were 2.79 times more likely to have normal vitamin D levels than patients with OPL (p<0.001). Finally, non-erosive OLP patients were ten times more likely to have normal vitamin D levels than erosive OLP patients (p<0.01).

Conclusions: Vitamin D levels might influence the evolution of OLP.