Introduction: Vitamin D plays a crucial role in many biological processes, such as regulating calcium-phosphate metabolism, enhancing immune response, and stimulating the mineralization of hard tissues. Vitamin D deficiency affects up to 30% of children in developed countries, especially during the autumn-winter period. In the context of dentistry, reduced vitamin D levels are associated with increased caries activity, including severe early childhood caries. Material and Methods: A literature review was conducted using the PubMed database. The analysed studies assessed diverse populations in terms of age, geographical location, and socioeconomic status. Results: The optimal level of vitamin D is considered to be at least 75 nmol/L. Vitamin D deficiency is associated with various systemic diseases, including dental caries. Children with severe early childhood caries have lower levels of vitamin D, which increases their susceptibility to caries. Adequate vitamin D levels promote enamel mineralization, increase salivary flow, and salivary calcium content, which protect against cariogenic microorganisms. There is also evidence linking maternal vitamin D levels and the risk of caries in their children. Conclusions: Vitamin D plays a crucial role in the prevention and treatment of dental caries, especially in children. Promoting vitamin D supplementation, according to Polish guidelines, can significantly reduce the risk of caries. Research on genetic polymorphisms opens new perspectives for the individualization of caries prevention strategies. Monitoring vitamin D levels in expectant mothers can also contribute to reducing the risk of caries in their offspring. Further research is needed to better understand the mechanisms of vitamin D impact on oral health and to develop detailed recommendations for supplementation.