Zhang HJ, Zhang JR, Mao CJ, et al. - Among 182 patients with Parkinson disease (PD) and 185 healthy controls, researchers ascertained if serum vitamin D levels were related with bone mineral density (BMD) and non-motor symptoms. Using partial correlation analysis, links between serum vitamin D levels and clinical data were assessed. Significantly lower serum 25(OH)D levels were seen in patients with PD vs healthy controls. Lower vitamin D levels in patients with PD were related to a significantly higher frequency of falls and insomnia and significantly higher scores for the Pittsburgh Sleep Quality Index, depression, and anxiety. Vitamin D levels were significantly associated with falls, insomnia, and scores for the Pittsburgh Sleep Quality Index, depression, and anxiety after adjusting for age, sex, and BMI. However, there were no connections in PD patients between BMD and serum 25(OH)D levels. Therefore, supplementation with vitamin D is a potential therapy for symptoms of non-motor PD.