Correlation between Vitamin D Levels and Healing Time in Lower Limb Fractures

Vitamin D plays a central role in calcium-phosphate metabolism and bone healing. Deficiency is common among fracture patients and may contribute to delayed union, particularly in weight-bearing lower-limb fractures. The purpose of this study was to assess the relationship between lower limb fracture healing time and baseline serum Vitamin D levels.

A prospective, observational, multi-center study was conducted from January 2022 to December 2024. Adult patients with acute lower-limb fractures were enrolled. Within a week following the injury, baseline serum 25-hydroxyvitamin D levels were assessed. The levels of Vitamin D were categorized as adequate (>30 ng/mL), inadequate (20-30 ng/mL), or deficient (<20 ng/mL). Healing time was recorded clinically (pain-free weight bearing) and radiologically (radiographic union scale for tibial fractures score ≥12). Statistical analysis included correlation and regression models.

A total of 120 patients (mean age 44.8 ± 13.2 years, M:F = 1.6:1) were included. The mean Vitamin D level was 21.6 ± 8.4 ng/mL; deficiency was present in 45.0%, insufficiency in 31.7%, and sufficiency in 23.3%. The mean healing time was 16.4 ± 3.8 weeks, with faster healing in sufficient patients (14.8 ± 2.9 weeks) compared to insufficient (16.7 ± 3.2 weeks) and deficient (17.9 ± 3.9 weeks) groups (P < 0.001). Vitamin D levels continued to be an independent predictor on regression analysis (β = -0.41, P < 0.001) and had a negative correlation with healing time (r = -0.62, P < 0.001).

Higher incidences of delayed union and longer healing durations were linked to lower baseline Vitamin D levels. Patients with lower limb fractures may have better results with routine screening and deficit repair.