NAD+ Metabolism and Cellular Health

Nicotinamide adenine dinucleotide (NAD+) sits at the heart of cellular energy transduction and signalling, acting as an essential redox cofactor and substrate for a range of enzymes that regulate metabolism, genome maintenance and stress responses. In its oxidised form, NAD+ accepts electrons in glycolysis, the tricarboxylic acid cycle and oxidative phosphorylation, cycling between NAD+ and NADH to drive ATP synthesis. Beyond bioenergetics, NAD+ fuels the activity of sirtuin deacetylases and poly(ADP-ribose) polymerases, which orchestrate chromatin remodelling, DNA repair and cellular adaptation to metabolic or genotoxic stress. Levels of NAD+ decline with age and in a spectrum of pathologies, including cardiovascular disease, neurodegeneration and metabolic syndrome, due to increased consumption by NAD-dependent enzymes, upregulation of hydrolases such as CD38, and diminished capacity of biosynthetic pathways. Restoration of NAD+ homeostasis through administration of precursors—nicotinamide mononucleotide (NMN) or nicotinamide riboside (NR)—or by modulating key biosynthetic enzymes has emerged as a promising strategy to rejuvenate mitochondrial function, improve vascular tone and maintain neuronal integrity. The interplay between NAD+ supply, compartmentalised redox balance and enzymatic consumption underpins a global framework for cellular health and resilience.

Research from Nature Portfolio

Longitudinal human trials have established that chronic supplementation with the NAD+ precursor NR is safe, well tolerated and effectively elevates the NAD+ metabolome in middle-aged and older adults, with preliminary indications of improved vascular function and reduced arterial stiffness. Detailed pharmacokinetic investigations have further shown that NR is orally bioavailable in both mice and humans, producing dose-dependent increases in blood and hepatic NAD+ levels with superior kinetics relative to other B3 vitamers. These foundational findings validate NR as a practical NAD+-boosting intervention and set the stage for larger clinical studies targeting age-related decline in metabolic and cardiovascular health.

NAD+ Metabolism and Cellular Health publication trend

The graph below shows the total number of articles in nad+ metabolism and cellular health across all publications each year (not limited to Nature Index journals).

Technical terms

Nicotinamide adenine dinucleotide (NAD+): An oxidised cofactor that accepts electrons in metabolic reactions and serves as a substrate for NAD+-dependent enzymes.

Salvage pathway: A metabolic route that recycles nicotinamide or nicotinamide riboside into NAD+ via sequential enzymatic steps.

Poly(ADP-ribose) polymerase (PARP): A family of nuclear enzymes that consume NAD+ to add ADP-ribose polymers onto target proteins during DNA repair.

Sirtuins: A class of NAD+-dependent deacetylases that regulate gene expression, mitochondrial biogenesis and stress responses through removal of acetyl groups from proteins.

CD38: A membrane-associated NAD+ hydrolase that degrades NAD+ to nicotinamide and cyclic ADP-ribose, modulating calcium signalling and immune responses.

Redox cofactor: A molecule, such as NAD+/NADH, that undergoes reversible oxidation and reduction to facilitate electron transfer in metabolism.

References

1. NAD+ metabolism: pathophysiologic mechanisms and therapeutic potential. Signal Transduction and Targeted Therapy (2020).
2. NAD+ exhaustion by CD38 upregulation contributes to blood pressure elevation and vascular damage in hypertension. Signal Transduction and Targeted Therapy (2023).
3. NMNAT2 supports vesicular glycolysis via NAD homeostasis to fuel fast axonal transport. Molecular Neurodegeneration (2024).
4. Nicotinamide riboside is uniquely and orally bioavailable in mice and humans. Nature Communications (2016).
5. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nature Communications (2018).