Title : Vitamin D Status and Supplementation in Orthopaedic Trauma: A Systematic Review and Meta-analysis of Fracture Union, Infection, and Functional Outcomes.
Abstract:
Background:
Vitamin D deficiency is biologically plausible as a modifiable risk factor across orthopaedic trauma outcomes,yet no comprehensive synthesis has examined prevalence,fracture healing, infection, and prevention within a unified framework.
Methods:
A systematic review and meta-analysis was conducted following PRISMA 2020 guidelines (PROSPERO:CRD420261380380).PubMed,medline via ovid,embase,and centeral were searched from inception to April 2026.Adults with orthopaedic trauma were eligible. Randomised trials were assessed using Cochrane RoB 2 and observational studies using the New castle-Ottawa Scale.Meta-analysis was performed for fracture prevention using random-effects inverse-variance weighting; remaining domains were narratively synthesised owing to clinical and methodological heterogeneity.
Results:
Twenty-three primary studies (N = 396,502 participants) were included across four domains, with four contextual studies retained for interpretation. Prevalence studies reported combined Vitamin D deficiency and insufficiency in 43–86% of orthopaedic patients at presentation. Dark skin pigmentation (OR ~5.5), winter presentation,and obesity were the most consistent independent risk factors. In fracture healing, persistent deficiency was independently associated with delayed union in observational studies (9.7% vs. 0.3% in patients remaining deficient versus sufficient after supplementation; population-level OR 1.14, 95% CI 1.05–1.22). The only randomised trial was underpowered and negative. In infection, five of seven observational studies reported significantly lower 25-hydroxyvitamin D concentrations in infected patients (strongest effect estimate OR 5.94). However, acute inflammation suppresses hydroxyvitamin D perioperatively,critically undermining causal interpretation.Meta-analysis of four fracture-prevention RCTs yielded a pooled HR of 0.83 (95% CI 0.73–0.94; I²=45%);sensitivity analysis restricted to trialsachieving≥800 IU/day yielded HR 0.75 (95% CI 0.64–0.88), suggesting a clinically significant dose-response threshold.
Conclusion:
Vitamin D deficiency is common in orthopaedic trauma and associated with adverse outcomes.Supplementation at≥800 IU/day reduces fracture incidence in vitamin-D-depleted elderly patients.Evidence for healing and infection remains observational.
