Correlation of vitamin D levels in children to the risk of dental caries: A Meta-analysis

Objective　To systematically evaluate the relationship between vitamin D levels and dental caries risk in children. Methods　PubMed, Embase, Web of Science, the Cochrane Library, Wanfang Digital Journal Full-text Database, China National Knowledge Infrastructure (CNKI), and database for Chinese Technical Periodicals (VIP) till Mar. 2019 were searched for the studies to evaluate the relationship between vitamin D levels in children and the risk of dental caries. Two evaluation staff independently selected the literature, extracted data and evaluated the bias risk of the study. Meta-analysis was performed using Stata15.1 software. Pooled relative risks (RR) with 95% confidence intervals (CIs) were calculated by random-effects models. Results　A total of 14 studies were included in 10 articles, with high methodological quality. Of the 14 studies, 6 cross-sectional studies were grade A, 3 cohort studies were grade A, 4 case control studies were grade B, and one Mendel randomized study was Grade A. A total of 12 596 subjects were included, among them 5338 were caries patients, the caries rate was 42.38%; Among 1075 cases of shortage in vitamin D, 512 were caries patients, the caries rate was 47.63%; Among 3676 cases of deficiency in vitamin D, 1580 were caries patients, the caries rate was 42.98%; Among 7845 cases with normal level of vitamin D, 3246 were caries patients, the caries rate was 41.38%. Meta-analysis showed that the suboptimal vitamin D level in children increased the risk of caries by 11% (RR=1.11, 95%CI: 1.01-1.21) with statistical significance (P=0.03). The results of subgroup analysis showed that, according to the study type, 4 case-control studies showed that the suboptimal vitamin D level in children increased the risk of caries by 61% (RR=1.61, 95%CI: 1.09~2.39, P=0.01); 6 cross-sectional studies and 3 cohort studies showed no significant difference in the correlation between the suboptimal vitamin D level and the risk of dental caries. According to the age of the subjects, lack or deficiency of vitamin D level increased the risk of caries by 74% in deciduous teeth group (RR=1.74, 95% CI: 1.37-2.21) with statistical significance (P<0.01). There were no significant difference in the correlation between lack or deficiency of vitamin D level and the risk of dental caries in groups of constant teeth period and replacement teeth period. Conclusion　The vitamin D levels in children is associated with the risk of dental caries, and vitamin D shortage or deficiency may increase the risk of dental caries. DOI: 10.11855/j.issn.0577-7402.2020.02.14