Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults
Randomized, double-blind, placebo-controlled 2×6-week crossover trial in healthy middle-aged and older adults: oral nicotinamide riboside (NR) was well tolerated, increased NAD+ and related metabolites in PBMCs versus placebo, and reported exploratory blood-pressure and arterial-function signals the authors position for future dedicated trials.
Design
2 × 6-week double-blind placebo-controlled crossover in healthy middle-aged and older adults; oral NR vs placebo (order randomized).
NAD+ metabolome
Blood NAD⁺ and related metabolites in PBMCs rose during NR periods versus placebo (paired analyses in completers; see paper Fig. 2).
Exploratory cardiovascular readouts
Figures address SBP/DBP/pulse pressure and aortic pulse wave velocity, carotid compliance, and brachial FMD—authors stress hypothesis-generating nature and the need for larger outcome-driven trials.
Evidence hygiene
NR-specific human PK/metabolome paper; do not merge numeric claims with NMN trials (Iida, Mishra, Yamanaka). Distinct from Sutton et al. 2018 early time-restricted feeding (PMID 29754952), which is a meal-timing / IF trial indexed under time-restricted eating and intermittent fasting in this wiki.
Outcomes
- NAD+ LevelNR vs placebo periods: increased PBMC NAD+ and related NAD metabolome markers vs placebo in crossover completers (see primary figures and statistics).
- Arterial StiffnessExploratory vascular-function indices (e.g., aortic PWV, carotid compliance, FMD) reported NR vs placebo with authors framing as preliminary—read full text before clinical inference.