The Association Between Low Levels of Serum Vitamin D and the Duration and Severity of Parkinson’s Disease

Abstract

Background: Parkinson’s disease is a neurodegenerative disorder more commonly seen in people aged over 50 years old. The etiology of the disease is unknown, yet the impact of factors, such as vitamin D as a hormone on Parkinson's disease has been demonstrated in previous studies. Objectives: The aim of the current study was to investigate the role of low levels of this factor on the severity and duration of the disease. Methods: In 2015 to 2016, the current researchers conducted this case-control study on 50 patients with Parkinson's disease and 50 healthy subjects as the control group in Babol, Iran. Demographic information (age, gender, and education), serum levels of vitamin D in the two groups, disease duration, disease severity, and cardinal features of the disease in the patient group were investigated. Data were analyzed using the SPSS 23 software with the t-test, Kruskal Wallis, Mann-Whitney, and adjusted logistic regression. Results: The mean serum vitamin D levels was 27.28 ± 27.75 (ng/mL) and 32.00 ± 17.76 (ng/mL) in patient and control groups, respectively (P = 0.009). In terms of the duration of the disease, 34 (68%) patients had the disease for less than five years, nine (18%) for five to ten years and seven (14%) for more than ten years. The duration was significantly higher in females (P = 0.001). Logistic regression analysis with adjusted demographic variables showed that the observed lower levels of serum vitamin D in cases compared with the control group was statistically significant (OR = 4.17; 95% CI: 1.37, 12.71; P = 0.012). Conclusions: There was a significant relationship between low serum vitamin D levels and the duration and severity of Parkinson's disease in patients under 60 years of age.