Vitamin B3
Niacin: nicotinic acid and nicotinamide/niacinamide
Water-soluble vitamins
Aliases / common names
Niacin; nicotinic acid; niacinamide; nicotinamide; NAD precursors
Natural food sources
Meat, poultry, fish, peanuts, legumes, whole grains and fortified grains; tryptophan can convert to niacin.
Main wellness functions
Supports NAD/NADP-dependent energy metabolism, skin, nerves and digestive function.
Deficiency signs
Pellagra: dermatitis, diarrhea, dementia and, if untreated, death.
Recommended intake
Adults: 14 mg NE/day women, 16 mg NE/day men. Children: about 6-16 mg NE/day. Pregnancy: 18 mg NE/day. Adult UL: 35 mg/day for supplemental nicotinic acid/niacin equivalents causing flushing.
Excess intake effects
Nicotinic acid can cause flushing, itching, liver injury, hyperglycemia and hyperuricemia at high doses.
Contraindicated / caution groups
Liver disease, peptic ulcer, gout, diabetes or lipid-lowering therapy require medical supervision for high-dose niacin.
Common dosage forms
Tablets, capsules, sustained-release niacin, niacinamide, B-complex.
Common product strengths
16-100 mg in multivitamins; 250-500 mg specialty niacin products should be supervised.
Use precautions
Do not use high-dose niacin for cholesterol management without medical care.
Supplement notes
Niacinamide has less flushing but is not the same as lipid-lowering nicotinic acid.
This information is for general nutrition education and product reference only. It does not replace medical diagnosis, treatment or individualized dietary advice.