What it does in the body
- NAD+/NADH-dependent energy metabolism (glycolysis, TCA cycle, ETC)
- NADP+/NADPH-dependent biosynthesis and antioxidant defense
- DNA repair via PARP enzymes (poly-ADP-ribose polymerases)
- Sirtuin-mediated gene expression and longevity pathways
- Lipid metabolism (high-dose nicotinic acid lowers VLDL/LDL, raises HDL)
How much you need (Daily Value)
| Group | Recommended | Source |
|---|---|---|
| Adult male | 16 mg NE (niacin equivalents) | NIH/IOM |
| Adult female | 14 mg NE | NIH/IOM |
| Pregnancy | 18 mg NE | WHO/IOM |
| Children | 6-12 mg NE (ages 1-13) | WHO |
| Older adults | 16 mg NE (male), 14 mg NE (female) | NIH |
Richest food sources
| Food | Amount | Where |
|---|---|---|
| Chicken breast | 14.8 mg per 100g | global |
| Tuna (yellowfin) | 18.5 mg per 100g | global |
| Turkey breast | 11.8 mg per 100g | Americas/Europe |
| Peanuts (roasted) | 12.1 mg per 100g | Americas/Africa |
| Mushrooms (portobello) | 5.0 mg per 100g | global |
| Brown rice | 4.3 mg per 100g | Asia |
| Fortified cereals | 5-20 mg per serving | Americas/Europe |
| Nixtamalized corn tortilla | 1.5 mg per tortilla (bioavailable) | Mesoamerica |
In our food database, per 100 g
Highest among our free foods — open the Food Explorer to compare.
If you don't get enough
Mild: Fatigue, poor concentration, mouth sores, indigestion
Moderate: Glossitis, skin hyperpigmentation on sun-exposed areas, irritability, insomnia
Severe: Pellagra: Casal necklace (photosensitive dermatitis), watery diarrhea, dementia, and death if untreated
Time to onset: Pellagra develops within 50-60 days of niacin-free diet
Too much
Upper limit: 35 mg/day (from supplements/fortified foods, based on flushing threshold for nicotinic acid)
Nicotinic acid: flushing, pruritus, hepatotoxicity at >2g/day (especially sustained-release). Nicotinamide: hepatotoxicity at >3g/day. New-onset diabetes risk at pharmacological doses.
How well you absorb it
Nearly 100% absorption at physiological doses; even at high doses well absorbed
Helped by: Adequate riboflavin and B6 (needed for tryptophan-to-niacin conversion pathway), Adequate protein/tryptophan intake
Hindered by: Corn-based diets without nixtamalization (niacin bound as niacytin), Leucine excess (inhibits tryptophan-niacin conversion), Isoniazid (depletes pyridoxine needed for conversion)
Cooking & storage
Niacin is the most stable of the B vitamins — resistant to heat, light, oxidation, and acid/alkali. However, significant amounts leach into cooking water when boiling. Nixtamalization of corn (lime-water treatment) releases bound niacin, which is why Mesoamerican populations avoided pellagra.
Nutrisize Health totals every nutrient from what you actually eat, against targets set for your age and sex, and flags what's short — across 4,995 foods, on your device.
