From the Guidelines
NAD (nicotinamide adenine dinucleotide) is a crucial coenzyme found in all living cells that plays a vital role in metabolism and cellular function, serving as an electron carrier in redox reactions and involved in energy production, DNA repair, gene expression regulation, cell signaling, and maintaining cellular health 1.
Key Functions of NAD
- Energy production through cellular respiration
- DNA repair and gene expression regulation
- Cell signaling and maintaining cellular health
- Exists in two forms: NAD+ (oxidized) and NADH (reduced)
Importance of NAD
NAD levels naturally decline with age, which has been linked to various age-related conditions and metabolic disorders, sparking interest in NAD precursors like nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) as potential supplements to boost NAD levels 1.
Dietary Sources of Niacin
Niacin, a precursor to NAD, can be obtained from the diet through various whole and processed foods, including fortified packaged foods, meat, poultry, red fish, nuts, legumes, and seeds, with the highest contents in fortified packaged foods and meat 1.
Synthesis of NAD
Niacin can be synthesized from the amino acid tryptophan in the liver, with 1 mg of nicotinamide equivalent to 1 niacin equivalent (NE) 1.
Potential Benefits of NAD Precursors
Research on the long-term benefits of NAD precursors like NR and NMN in humans is still ongoing, but they may have potential in preventing or treating age-related conditions and metabolic disorders 1.
From the Research
Definition and Function of NAD
- Nicotinamide adenine dinucleotide (NAD) is a vital coenzyme in redox reactions 2, 3, 4, 5
- NAD is also an essential cofactor for non-redox NAD+-dependent enzymes, including sirtuins, CD38, and poly(ADP-ribose) polymerases 3, 5
- NAD plays a critical role in energy production pathways, including the tricarboxylic acid (TCA) cycle, fatty acid oxidation, and oxidative phosphorylation 5
Role of NAD in Cellular Processes
- NAD regulates energy metabolism, DNA damage repair, gene expression, and stress response 5
- NAD is consumed by PARPs, SARM1, sirtuins, and CD38, and its levels regulate several essential processes including DNA repair, immune cell function, senescence, and chromatin remodelling 2
- NAD influences many key cellular functions, including metabolic pathways, DNA repair, chromatin remodelling, cellular senescence, and immune cell function 3
Importance of NAD in Ageing and Disease
- Declining NAD+ levels have been linked to several age-related diseases, including various metabolic diseases and cognitive decline 2, 3
- NAD+ metabolism has emerged as a potential target to ameliorate age-related diseases 2, 3
- Maintaining appropriate NAD levels is important for mitochondrial function, and decreased NAD levels are observed in neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease 5