Could vitamin D deficiency have an impact on motor and cognitive function in Parkinson’s disease?

Abstract

Abstract Background Multiple epidemiological data showed a significant higher prevalence of hypovitaminosis D in patients with Parkinson’s disease (PD). Objectives To assess the serum vitamin D level in patients with Parkinson’s disease and to investigate the possible relationship between the serum vitamin D level and both motor and cognitive symptoms in Parkinson’s disease Materials and methods A case-control study was conducted on 25 patients who fulfilled the criteria for diagnosis of idiopathic Parkinson’s disease based on the British Brain Bank criteria, and 25 healthy volunteers. Selected PD patients were submitted for assessment of cognitive function using the PD - Cognitive Rating Scale (PD-CRS) and assessment of motor function using the Unified Parkinson’s Disease Rating Scale (UPDRS). Serum 25 hydroxy vitamin D level was measured for all the included patients and controls. Results PD patients were found to have a significantly lower level of serum vitamin D than controls (P value = 0.001). There was a statistically significant negative correlation between the serum vitamin D level and the scores of motor, mentation, activities of daily living, medication complication, other complications, and the total score of UPDRS (P value = 0.01, < 0.001, 0.012, 0.017, 0.039, and 0.002 respectively). There was a statistically significant positive correlation between the serum vitamin D level and the scores of attention, working memory, immediate recall, delayed recall, naming, visuoperceptual abilities, visuoconstructional abilities, alternating verbal fluency, action verbal fluency, and the total score of PD-CRS (P value < 0.001 in all parameters). Conclusion Vitamin D deficiency is evident in PD patient, and such deficiency significantly affected both motor and cognitive symptoms.

Keywords

• Parkinson’s disease
• Vitamin D
• PD-CRS
• UPDRS