A Randomized Controlled Trial of Nicotinamide Riboside Supplementation in Early Parkinson's Disease

Inclusion Criteria: * Have a clinical diagnosis of idiopathic PD according to the MDS clinical diagnostic criteria for Parkinson's disease * \[¹²³I\]FP-CIT single photon emission CT (DaTscan) confirming nigrostriatal degeneration * Diagnosed with PD within 2 years from enrolment * Hoehn and Yahr score \< 3 at enrolment * Optimal symptomatic therapy, not requiring adjustments, for at least 1 month. * Age equal to or greater than 35 years at time of enrolment. Exclusion Criteria: * Dementia or other neurodegenerative disorder at baseline visit * Diagnosed with atypical parkinsonism or vascular parkinsonism * Any psychiatric disorder that would interfere with compliance in the study. * Any severe somatic illness that would make the individual unable to comply and participate in the study. * Use of high dose vitamin B3 supplementation within 30 days of enrolment * Metabolic, neoplastic, or other physically or mentally debilitating disorder at baseline visit. * Genetically confirmed mitochondrial disease