From: The relationships of vitamin D, vitamin D receptor gene polymorphisms, and vitamin D supplementation with Parkinson’s disease
Author
Country
Type of study
Number of participants (T/C)
Intervention
Follow-up
Adverse events
Hiller et al. 2018 [148]
USA
RCT
27/24
Vitamin D3 10,000 IU/day
16 weeks
None
Suzuki et al. 2013 [41]
Japan
56/58
Vitamin D3 1200 IU/day
12 months