NAD+

Functions & Mechanisms​​

1. ​​Core of Energy Metabolism​​

   • NAD⁺ acts as a "universal currency" in cellular energy production, driving ATP synthesis through glycolysis, the Krebs cycle, and mitochondrial respiration
   • The redox balance between NAD⁺ and NADH is pivotal for energy conversion

2. ​​DNA Repair & Anti-Aging​​

   • Activates sirtuins (e.g., SIRT1) to regulate gene expression and delay aging
   • Supports PARP enzymes in DNA repair, mitigating telomere attrition and age-related diseases like Alzheimer’s

3. ​​Metabolic & Immune Regulation​​

   • Modulates glucose and lipid metabolism, improving insulin sensitivity and obesity
   • Reduces pro-inflammatory cytokines (e.g., TNF-α, IL-6) and enhances immune responses

4. ​​Circadian Rhythm & Cardiovascular Health​​

   • Stabilizes circadian clocks, enhancing sleep quality
   • Protects cardiac function against ischemic damage

​​4. Biosynthesis & Supplementation Strategies​​

1. ​​Synthesis Pathways​​

   • ​​De Novo Pathway​​: Converts tryptophan to NAD⁺ via the kynurenine pathway
   • ​​Salvage Pathway​​: Efficiently generates NAD⁺ from nicotinamide (NAM) through NMN intermediates
   • ​​Preiss-Handler Pathway​​: Utilizes nicotinic acid (NA) to produce NAD⁺

2. ​​Supplementation Methods​​

   • ​​Precursors​​: NMN and NR are highly effective in elevating NAD⁺ levels
   • ​​Intravenous Infusion​​: Direct NAD⁺ administration rapidly improves cellular functions but requires clinical expertise
   • ​​Diet & Lifestyle​​: Caloric restriction, intermittent fasting, and vitamin B3-rich foods (e.g., fish, nuts) support NAD⁺ synthesis

​​5. Anti-Aging Applications & Challenges​​

• ​​Clinical Potential​​: NAD⁺ supplementation may delay aging phenotypes, such as mitochondrial dysfunction and skin aging
• ​​Research Gaps​​: Long-term safety and optimal dosing require further validation