Abstract
Circulating vitamin D has previously been found to be lower in patients with Parkinson’s disease (PD), while the effects of sunlight exposure have not yet been fully investigated. Therefore, we evaluated the associations between serum vitamin D, vitamin D intake, sunlight exposure, and newly-diagnosed PD patients in a Chinese population. This case-control study measured serum 25-hydroxyvitamin D (25(OH)D) levels and sunlight exposure in 201 patients with newly-diagnosed PD and 199 controls without neurodegenerative diseases. Data on vitamin D intake and sunlight exposure were obtained using a self-report questionnaire. Multivariable logistic regressions were employed to evaluate the associations between serum 25(OH)D levels, sunlight exposure, and PD. Adjustments were made for sex, age, smoking, alcohol use, education, BMI, and vitamin D intake. There were significantly lower levels of serum 25(OH)D (20.6 ± 6.5 ng/mL), daily vitamin D intake (8.3 ± 3.7 g/day), and sunlight exposure (9.7 ± 4.1 h/week) in patients with PD compared to healthy controls (p < 0.05). Crude odds ratios (ORs) for PD in the quartiles of serum 25(OH)D were 1 (reference), 0.710 (0.401, 1.257), 0.631 (0.348, 1.209), and 0.483 (0.267, 0.874), respectively. Crude ORs for PD in quartiles of sunlight exposure were 1 (reference), 0.809 (0.454, 1.443), 0.623 (0.345, 1.124) and 0.533 (0.294, 0.966), respectively. A significant positive correlation between serum 25(OH)D and sunlight exposure was found, but serum 25(OH)D was not correlated with daily vitamin D intake. This study indicates that lower levels of serum 25(OH)D and sunlight exposure are significantly associated with an increased risk for PD.
Highlights
Parkinson’s disease (PD) is a common progressive neurodegenerative disorder mostly occurring in elderly humans
A significant positive correlation between serum 25(OH)D and sunlight exposure was found, but serum 25(OH)D was not correlated with daily vitamin D intake
This study indicates that lower levels of serum 25(OH)D and sunlight exposure are significantly associated with an increased risk for PD
Summary
Parkinson’s disease (PD) is a common progressive neurodegenerative disorder mostly occurring in elderly humans. The pathogenesis of PD is unclear, environmental factors, including some vitamins, have been suggested to be linked with the development of PD [1,2,3,4,5,6]. Vitamin D has recently emerged as a critical factor in the pathogenesis of chronic diseases and progressive neurodegenerative disorders [5,7,8]. Sources of vitamin D include exposure to sunlight, diet, and vitamin D supplements. Neither diet alone, nor the current recommendation of 800 to 1200 international units of vitamin D supplementation may be enough to provide adequate levels of circulating 25(OH)D. 20% of vitamin D is obtained from food (eggs, fish, animal liver, and dairy products), whereas 80% is obtained from ultraviolet
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
