A number of environmental factors such as age, obesity, excessive mechanical loading, injury, vibration, and smoking status, were reported to have an impact on disc degeneration.[38] However, more and more evidence showed that genetic factors may play a critical role in occurrence of disc degeneration.[39] Among these genetic factors, the allelic variants of the gene encoding VDR, include TaqI (rs731236), FokI (rs2228570) and ApaI (rs7975232) have been reported to be associated with disc degeneration risk. This evidence concerns the gene VDR and obesity due to melanocortin 4 receptor deficiency.