Vitamin B3 (Niacin)

The source of NAD⁺, the molecule behind energy, repair and healthy aging.

Mechanisms, studies and evidence grades for each claim above.

Core mechanism

Niacin converts to NAD⁺/NADP⁺, which carry electrons and enable ATP production and cellular metabolism broadly.

Energy metabolism

NAD⁺ accepts electrons across glycolysis, the TCA cycle, and oxidative phosphorylation, driving ATP production via the electron transport chain.¹

Redox / cellular metabolism

NAD⁺/NADH regulate cellular redox state; NADP⁺/NADPH support biosynthesis (lipids, cholesterol) and antioxidant systems.²

DNA repair / longevity

NAD⁺ is a substrate for PARPs (DNA repair enzymes) and sirtuins (cellular regulation, stress response).³

Brain

Supports neuronal energy metabolism; NAD⁺ depletion is linked to impaired brain function.

Skin / deficiency

Niacin deficiency produces pellagra — the classic triad of dermatitis, diarrhea, and dementia¹ — reflecting systemic energy failure rather than a skin-specific problem.

Transport / synthesis

Can come from diet or be synthesized from tryptophan, which itself requires vitamin B6. See Vitamin B6.

Intake

Roughly 14–16 mg/day.

Top foods

• Chicken
• Turkey
• Tuna
• Salmon
• Beef

Key insight

Vitamin B3 provides NAD⁺, a central molecule required for energy production, redox balance, and cellular repair.¹

References