Relationship of vitamin D with bone mineral density, fracture type and social deprivation in neck of femur fractures

Abstract

Background Reduced bone mineral density is recognised as a risk factor for hip fractures and fragility fractures in general. Vitamin D is important in maintaining healthy bone mineral levels and can therefore affect risk of hip fracture. We investigated the correlation between vitamin D levels and bone mineral density, as well as fracture type, in neck of femur fractures and also assessed the relationship of vitamin D and social deprivation. Method We included all patients admitted to our department, with a neck of femur fracture over one year (October 2013 to October 2014). We analysed vitamin D levels for all patients during admission and compared these to bone mineral density scores, based on DEXA scan results; hip fracture type & comminution, based on admission radiographs; and levels of social deprivation, based on the patient9s address. Results In total 360 patients were admitted over the study period, with a neck of femur fracture, of which 298 had vitamin D assessed and 76 had DEXA scans. Of these cohorts, 71% were found to be vitamin D deficient and 7% had osteoporosis. No significant correlation was found between vitamin D scores and bone density, or with level of vitamin D deficiency and fracture type or comminution. A significant correlation was however identified, between low vitamin D levels and decreasing levels of social deprivation (R=0.11, p=0.04). Conclusion No relationship was identified between vitamin D levels and hip fracture type, suggesting that vitamin D cannot be used to predict patients at risk of more comminuted fractures. Although no relationship was also identified for bone mineral density and vitamin D, this may be because the sample size of DEXA scans was relatively small. Interestingly the relationship between vitamin D and social deprivation was the reverse of what was expected and suggests that affluent individuals may be at greater risk of low vitamin D.