Vitamin D level and fractures in children and adolescents: a systematic review and meta-analysis

Introduction: The aim of the study was to determine the relationship between vitamin D levels and the risk of bone fractures in children and adolescents. Materials and methods: PubMed, Embase, and Cochrane library databases were searched using subject and free words. The Newcastle–Ottawa scale form was used to assess literature quality. ReVman 5.2 and Stata 13.0 were used for statistical analyses. The results were expressed as the mean difference (MD)/odds ratio (OR) and 95% confidence interval (95% CI). The heterogeneity test was conducted according to I and Q tests. Egger’s test was used to evaluate publication bias. Results: Thirteen studies (3943 participants ≤ 18 years old) were included, and the quality of the literature was acceptable. Regarding the 25-hydroxyvitamin D (25OHD) level in the random effects model, the MD = − 0.12 ng/mL (95% CI: −1.93, 1.69), I = 83%, and P < 0.00001, indicating large heterogeneity. Subgroup analyses were conducted according to vitamin D supplementation and 25OHD level, the sources of heterogeneity were not found. Regarding the proportion of subjects with vitamin D deficiency in the random effects model, OR = 1.09 (95% CI: 0.67, 1.79), I = 79%, and P < 0.0001. By sensitivity analysis, after removing Al-Daghri’s study, OR = 1.22 (95% CI: 0.96, 1.56), I = 0%, and P = 0.64. Conclusion: There is no relationship between vitamin D level and the risk of bone fractures in children and adolescents.