Study record
Chronic nicotinamide riboside elevates NAD⁺ in healthy adults (Martens et al., 2018)
Human RCT — biomarker endpoint
○ Evidence tier 4 — Human RCT — biomarker endpoint
Record verify: source publication identified; see evidence and limitations
| Design | Randomized, double-blind, placebo-controlled crossover trial (biomarker) |
| N | 30 |
| Registry | NCT02921659 |
| PMID | 29599478 |
| DOI | 10.1038/s41467-018-03421-7 |
| Citation status | Original publication identity matched by title, author and DOI; relevant full-text sections, results and limitations examined 2026-10-14. The trial identifier is reported in the original source. |
Identifiers: DOI verified; PMC verified; PMID verified; trial registry id reported, not independently verified. Record-level verification and identifier-level status are separate: a record can be verified against its primary publication on one identifier while another is simply not confirmed. No identifier is fabricated, and none is left in a “pending” state.
Five-qualifier claim
| Species / population | 30 healthy adults aged 55–79 years were randomized in Boulder, Colorado; 24 completed the crossover trial (21 had analyzable NAD+ metabolomics). |
| Exposure, route, schedule | Oral NR 500 mg twice daily (1000 mg/day) for 6 weeks. |
| Comparator / duration | Placebo-controlled, double-blind, randomized crossover; 6-week periods. |
| Endpoint / numeric result | Peripheral-blood mononuclear-cell NAD+ was approximately 60% higher than placebo after 6 weeks. This was not a doubling of whole-blood NAD+. Blood-pressure and aortic-stiffness comparisons were not significant after multiple-comparison correction; exploratory post-hoc subgroup signals require confirmation. |
| What it did NOT establish | This trial does not establish reduced clinical events, mortality or longer lifespan. BP and aortic-stiffness findings were exploratory and were not significant after multiplicity correction. The sample-size calculation also targeted a clinically relevant FMD change. Favorable tolerability during the six-week NR period in this small cohort does not establish a broader or long-term safety profile. |
Interventions
Primary reference
https://doi.org/10.1038/s41467-018-03421-7
Exact identifier confirmed against the primary record via Crossref/ClinicalTrials.gov where stated in the citation status names the source and the date. An identifier that is not confirmed is named as such in the identifier row above, never filled in from a secondary source.