Flush-free vitamin B3, the cheapest way to feed the helper molecule driving cellular energy and repair of damaged genetic material. Strongest evidence is skin-based: creams improve the look of sun-aged and blemish-prone skin, and gram-level capsules lower new common skin cancers in people who have already had several, though that finding is unsettled. Outside the skin, results thin out. (Full Review)
| Marker | Target | Why |
|---|---|---|
| ALT | 10–26 U/L (men), 8–22 U/L (women) | Earliest signal of the reversible hepatic effect at gram doses |
| AST | 10–26 U/L | Confirms an ALT rise is hepatic rather than muscular |
| Homocysteine | Below 8 µmol/L | Directly tracks whether methyl-group demand is outrunning supply |
| Fasting glucose | 75–86 mg/dL | Detects the inconsistent insulin-resistance signal at multi-gram doses |
| HbA1c | 4.8–5.3% | Confirms whether a single glucose reading reflects a sustained shift |
| eGFR | Above 90 mL/min/1.73 m² | Governs clearance of niacinamide and both terminal metabolites |
| Serum phosphate | 2.5–4.0 mg/dL | Relevant only in advanced kidney disease, where niacinamide lowers it |
| Fasting insulin | 2–5 µIU/mL | Detects the insulin-resistance signal before fasting glucose moves |
| Dermatological lesion count | No established target — track change from own baseline | The only endpoint that defines success for chemoprevention |
Cadence: Liver enzymes and homocysteine at baseline, 3 months, then annually if stable; kidney function and glucose markers annually; dermatological review every 6 months