Association of serum vitamin D deficiency and inadequate sunlight exposure with Parkinson's disease risk: A pilot study in Bangladesh

A role for vitamin D deficiency and inadequate sunlight exposure in Parkinson's disease (PD) has been suggested. A cross-sectional study was conducted to estimate the association of vitamin D deficiency and inadequate sunlight exposure with PD. A total of 87 PD patients and 88 neurologically healthy general patients with normal liver and kidney functions were selected for the study using a systematic random sampling technique. Participants were recruited from a tertiary-level hospital in Dhaka, Bangladesh, following standard ethical guidelines and after obtaining informed consent. The neurologically healthy general patients group consisted of individuals with no history of neurological disorders, such as PD or Alzheimer's disease. Of vitamin D-deficient participants (plasma concentration <20 ng/mL), 66.7% had PD versus 33.3% who were neurologically healthy (P < 0.01); similarly, of participants with inadequate daily sunlight exposure, 63.4% had PD versus 36.6% who were neurologically healthy (P < 0.01). This study determined a significant association between vitamin D deficiency and PD (AOR 3.02, 95% CI 1.22, 7.48, p = 0.017). In addition, inadequate daily sunlight exposure was also significantly linked to PD status (AOR 2.31, 95% CI 1.16, 4.62, p = 0.018). The study concluded that low vitamin D levels and inadequate sunlight exposure may be related to PD. However, large-scale, multicenter longitudinal or experimental studies are needed to establish causal relationships.