Evaluation of Nicotinamide Riboside in Prevention of Small Nerve Fiber Axon Degeneration and Promotion of Nerve Regeneration

BACKGROUND AND AIMS: precursor. METHODS: To investigate if oral supplementation of synthetic NR can act as a therapeutic agent to prevent degeneration of small somatic sensory axons innervating the skin or promote regeneration of these same fibers in humans, we utilized a validated experimental model of cutaneous nerve degeneration and regeneration and conducted a placebo-controlled, double-blinded Phase 2 study. RESULTS: in the skin samples. NR supplementation did not prevent capsaicin-induced degeneration of the epidermal sensory nerve fibers, and there was no difference in the amount of epidermal reinnervation at the 90-day visit. Although there was a small but statistically significant increase in the number of epidermal sensory nerve fibers at the 60-day visit, these results are preliminary and will need to be validated in larger studies. INTERPRETATION: At present oral NR supplementation, at the doses used in this study, cannot be recommended to prevent neuropathy or to improve nerve regeneration.