The prevalence of hypovitaminosis D is currently increasing. A wide variety of diseases and complications are associated with low vitamin D serum concentrations, including poor fracture healing and... Show moreThe prevalence of hypovitaminosis D is currently increasing. A wide variety of diseases and complications are associated with low vitamin D serum concentrations, including poor fracture healing and fracture non-union. A healthy 44-y-old man presented himself with pain due to a non-union of a femoral shaft fracture at 4 y after the initial injury. The fracture had been operated upon three times and was adequately fixated in anatomic position. Hypovitaminosis D was diagnosed, and subsequent supplementation resulted in complete union of the fracture with full pain relief. This case illustrates the importance of adequate serum vitamin D levels in fracture healing, in addition to other fracture healing facilitating factors. With the increasing prevalence of hypovitaminosis D and possibly associated fracture-related complications, routine vitamin D determination should become part of clinical workup in cases of fracture non-union. (c) 2021 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) Show less