NAD Supplementation in Parkinson's Disease

Neurovascular Coupling, Clinical Outcomes, and NAD Supplementation in Parkinson's Disease

The goal of this clinical trial is to learn whether Nicotinamide Riboside, a form of Vitamin B3 also known as NR, can improve blood vessel health in the brain, memory, and physical function in eligible study participants. NR is considered investigational for this study because it is not yet established for this specific use.

The main questions it aims to answer are:

Can NR improve non-invasive measures of blood vessel health in the brain? Can NR improve memory testing results and physical function?

Researchers will compare participants who receive NR with participants who receive a placebo, an inactive substance that looks like the study drug, to see if NR has beneficial effects. Participants will be randomly assigned to receive either NR or placebo.

They will complete 3 study visits over 13 weeks at the Translational Geroscience Laboratory at the University of Oklahoma Health Campus. During the visits, participants will complete questionnaires, memory testing, non-invasive blood vessel measurements, physical function tests, and a blood draw.

Study Overview

• Status: Not yet recruiting
• Conditions: Parkinson's Disease
• Intervention / Treatment: Dietary supplement: Nicotinamide Riboside (NR); Dietary supplement: Oral placebo capsules

Detailed Description

This is a single-site, randomized, placebo-controlled clinical trial evaluating oral nicotinamide riboside (NR), a form of vitamin B3, in adults over 55 years of age with Parkinson's disease. NR is commercially available as a dietary supplement, however, its use in this study for Parkinson's disease is considered investigational because it is not approved by the U.S. Food and Drug Administration as a treatment for Parkinson's disease.

The purpose of this study is to explore whether daily NR supplementation over 12 weeks may improve measures related to brain health, memory, motor function, physical performance, and vascular function in participants with Parkinson's disease. Participants will be randomly assigned to receive either NR or placebo. Neither the participants nor the investigators will choose the assigned group.

Study participation includes 3 in-person visits: screening, baseline, and follow-up. Study procedures include collection of medical and health information, questionnaires, blood draw, memory and cognitive testing, non-invasive measurements of brain activity and blood vessel function, walking and balance assessments, grip strength testing, and use of a study watch to assess activity and sleep patterns.

The study procedures will be conducted at the Translational Geroscience Laboratory at the University of Oklahoma Health Sciences Center.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Zsuzsanna Tucsek-Cardon, PhD; Phone Number: 572-271-9161; Email: zsuzsanna-tucsekcardon@ou.edu
• Study Contact Backup: Name: Zsofia Szarvas, MD, PhD; Phone Number: 405-271-8130; Email: zsofia-szarvas@ou.edu

Study Locations

• United States
  • Oklahoma
    • Oklahoma City, Oklahoma, United States, 73117
      • Center for Geroscience and Healthy Brain Aging
      • Contact: Zsuzsanna Tucsek-Cardon, PhD; Phone Number: 572-271-9161; Email: zsuzsanna-tucsekcardon@ou.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Clinical diagnosis of Parkinson's disease according to Movement Disorder Society clinical diagnostic criteria (59), Hoehn and Yahr stages I-III at enrollment (ON medication state when applicable) (60).
• Age ≥55 years at enrollment.
• Adequate hearing and visual acuity to participate in the examinations
• Ability to provide written informed consent in English.
• Ability to complete study procedures, including seated tasks and walking tasks (with or without an assistive device, if needed for safety).
• Stable antiparkinsonian medication regimen for ≥4 weeks prior to baseline (or drug-naive).

Exclusion Criteria:

• Not able to communicate or follow instructions due to aphasia or severe cognitive impairment.
• Active CNS disease including multiple sclerosis, uncontrolled seizures, active cancer.
• Cerebrovascular accident other than TIA within 60 days prior to Visit 0.
• Major psychiatric disease, including major depression not currently controlled on medications, alcohol or drug abuse.
• Abnormal kidney function (creatinine >2mg/dL or EGFR <30mL/min) by most recent labs within 6 months prior to Visit 0.
• Elevated liver enzymes (AST and/or ALT above x2 upper limit of normal) by most recent labs within 6 months prior to Visit 0.
• Treatment with other NAD enhancers (Nicotinamide riboside or nicotinamide mononucleotide) within 4 weeks prior to randomization.
• Any other medical condition and/or unstable or severe medical illness which, in the opinion of investigator, would render the patient inappropriate or too unstable to complete the study protocol.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Active intervention; Participants will be randomized to receive either oral nicotinamide riboside at a total daily dose of 1 g or an identically appearing placebo for 12 weeks.	Dietary supplement: Nicotinamide Riboside (NR); Participants will be randomized to receive either oral nicotinamide riboside at a total daily dose of 1 g or an identically appearing placebo for 12 weeks.
Placebo Comparator: Placebo intervention; Participants assigned to the placebo arm will take an oral placebo capsule daily for 12 weeks. The placebo will appear identical to the nicotinamide riboside capsules.	Dietary supplement: Oral placebo capsules; 1 g identically appearing placebo capsule

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in task-evoked neurovascular coupling response measured by functional near-infrared spectroscopy	Neurovascular coupling will be assessed using functional near-infrared spectroscopy during study tasks. The primary reported value will be the change in task-evoked oxygenated hemoglobin response (change in oxygenated hemoglobin concentration in micromolar) from baseline to the 12-week follow-up visit. Changes will be compared between participants assigned to nicotinamide riboside and participants assigned to placebo.	Baseline to 12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in NIH Toolbox Cognitive Battery score	Cognitive performance will be assessed using the NIH Toolbox Cognitive Battery, a computer-based set of tests designed to measure cognitive domains such as memory, attention, executive function, and processing speed. The reported outcome will be the change in NIH Toolbox Cognitive Battery score from baseline to the 12-week follow-up visit. Changes will be compared between participants assigned to nicotinamide riboside and participants assigned to placebo.	Baseline to 12 weeks
Change in timed walking test completion	Walking performance will be assessed using a timed walking test. The reported outcome will be the change in time (seconds) required to complete the walking test from baseline to the 12-week follow-up visit.	Baseline to 12 weeks
Change in gait speed during single and dual-task walking	Gait speed will be measured using a pressure-sensing walkway during normal walking and while participants walk and perform a cognitive task, such as serial subtraction. The reported outcome will be the change in gait speed (meter/second) from baseline to the 12-week follow-up visit.	Baseline to 12 weeks
Change in handgrip strength	Handgrip strength will be measured using a hand-grip dynamometer. Three trials will be performed for each hand, and the reported value (kilograms-force) will be the average grip strength. The reported outcome will be the change in average handgrip strength from baseline to the 12-week follow-up visit.	Baseline to 12 weeks
Change in static balance performance	Static balance will be assessed while participants stand with eyes open and eyes closed on both a firm surface and a foam surface. The reported outcome will be the change in the selected balance parameter (seconds, sway area and center-of-pressure displacement) from baseline to the 12-week follow-up visit.	Baseline to 12 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline in NAD⁺ concentrations and circulating NAD-related metabolites	NAD⁺ concentrations and circulating NAD-related metabolites will be measured from blood samples collected at baseline and after 12 weeks of treatment. Changes from baseline to the 12-week follow-up visit will be compared between participants assigned to nicotinamide riboside and participants assigned to placebo.	Baseline to 12 weeks
Change in Montreal Cognitive Assessment score	Global cognitive function will be assessed using the Montreal Cognitive Assessment (MoCA), a brief screening tool used to evaluate memory and thinking problems. The reported outcome will be the change in total MoCA score (MoCA total score, range 0-30 points) from baseline to the 12-week follow-up visit and changes will be compared between participants assigned to nicotinamide riboside and participants assigned to placebo.	Baseline to 12 weeks
Change in Parkinson's motor rating scale score	Motor function will be assessed using a standard Parkinson's disease motor rating scale. The reported outcome will be the change in total motor score from baseline to the 12-week follow-up visit. Changes will be compared between participants assigned to nicotinamide riboside and participants assigned to placebo. Unit of Measure: Points on a scale	Baseline to 12 weeks
Change in body composition	Body fat percentage will be measured using a body composition scale. The reported outcome (percent) will be the change in body fat percentage from baseline to the 12-week follow-up visit.	Baseline to 12 weeks
Change in skeletal muscle mass	Skeletal muscle mass will be measured using a body composition scale. The reported outcome (kilograms) will be the change in skeletal muscle mass from baseline to the 12-week follow-up visit.	Baseline to 12 weeks
Change in sleep quality questionnaire score	Sleep quality will be assessed using a standardized sleep quality questionnaire. The reported outcome will be the change in total sleep quality score from baseline to the 12-week follow-up visit. Changes will be compared between participants assigned to nicotinamide riboside and participants assigned to placebo. Unit of Measure: Points on a scale	Baseline to 12 weeks
Change in fatigue questionnaire score	Fatigue will be assessed using a standardized fatigue questionnaire. The reported outcome will be the change in total fatigue score from baseline to the 12-week follow-up visit. Unit of Measure: Points on a scale	Baseline to 12 weeks
Change in food security questionnaire score	Food security will be assessed using a standardized food security questionnaire with a 30-day lookback period. The reported outcome will be the change in food security score from baseline to the 12-week follow-up visit. Unit of Measure: Points on a scale	Baseline to 12 weeks
Change in pain score	Pain will be assessed using a standardized pain scale or questionnaire. The reported outcome will be the change in pain score from baseline to the 12-week follow-up visit. Unit of Measure: Points on a scale	Baseline to 12 weeks
Change in daily step count measured by wrist-worn activity monitor watch	Physical activity will be assessed using a wrist-worn activity monitor. The reported outcome will be the change in average daily step count from baseline to the 12-week follow-up period. Unit of Measure: Steps per day	Baseline to 12 weeks
Change in total sleep time measured by wrist-worn activity monitor watch	Sleep duration will be assessed using a wrist-worn activity monitor. The reported outcome will be the change in average total sleep time from baseline to the 12-week follow-up period. Unit of Measure: Minutes per night	Baseline to 12 weeks

Collaborators and Investigators

• Sponsor: University of Oklahoma
• Collaborators: Presbyterian Health Foundation
• Investigators: Principal Investigator: Andriy Yabluchanskiy, MD, PhD, University of Oklahoma Health Campus

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: June 26, 2026
• First Submitted That Met QC Criteria: July 8, 2026
• First Posted (Actual): July 14, 2026

Study Record Updates

• Last Update Posted (Actual): July 14, 2026
• Last Update Submitted That Met QC Criteria: July 8, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: intervention; Parkinson's disease; brain health; nicotinamide riboside
• Additional Relevant MeSH Terms: Synucleinopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurodegenerative Diseases; Movement Disorders; Parkinsonian Disorders; Basal Ganglia Diseases; Parkinson Disease; nicotinamide-beta-riboside
• Other Study ID Numbers: 19742P

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No