Purpose: Previous surveys have reported that children with vitamin D deficiency were likely to suffer from early childhood caries (ECC). The aim of this systematic review and meta-analysis was to determine 1. whether the status of vitamin D is intrinsically related to the occurrence of ECC and 2. the optimal level of vitamin D for the prevention of ECC.
Materials and Methods: The database of PubMed, Web of Science, Cochrane, Embase and Google scholar were searched for targeted literature. The eligibility criteria were observational studies in which children with ECC were compared to children without ECC in terms of their vitamin D status. Applying the Newcastle-Ottawa tool, study selection, data extraction, and risk of bias assessment were performed by 2 reviewers independently. Meta-analysis was performed using the Cochrane Collaboration’s Review Manager 5.4 software.
Results: 501 articles were retrieved from the electronic databases; 11 studies were finally included in systematic review, 10 studies of which were submitted to meta-analysis. The 25(OH)D levels in the ECC group were statistically significantly lower compared with that in the caries-free group (WMD = -13.96, 95% CI: [-19.88,-8.03], p < 0.001), especially in regard to the association between S-ECC and vitamin D (WMD = -18.64, 95% CI: [-20.06,-17.22], p < 0.001). The subgroup analyses in terms of geographical region demonstrated that children with a level of 25(OH)D of 50–75 nmol/l were more likely to have ECC than those with over 75 nmol/l (OR = 1.42, 95% CI: [1.26,1.60], p < 0.001), with data from Asia and Europe combined for analysis
Conclusions: The level of vitamin D was lower in children with ECC than in caries-free children, and the correlation between S-ECC and vitamin D was even stronger. The optimal 25(OH)D level for preventing occurrence and development of ECC was ≥ 75 nmol/l. Thus, clinicians should view the development of early caries also from a systemic perspective.