Vitamin B3 (Niacin)
Vitamin B3 (Niacin)
Snapshot
Niacin (vitamin B3) is a water‑soluble B vitamin that supports cellular energy production, healthy lipid profiles, skin integrity, and nervous system function through its roles in NAD⁺/NADP⁺ coenzymes.
What is Vitamin B3 (Niacin)?
Niacin refers to nicotinic acid and its amide form nicotinamide. Both serve as precursors to nicotinamide adenine dinucleotide (NAD⁺) and NAD phosphate (NADP⁺), essential cofactors for redox reactions in metabolism and DNA repair.
Where It Comes From
Dietary niacin is found in meats, fish, nuts, legumes, and whole grains. It can also be synthesized endogenously from tryptophan. Supplemental forms include immediate‑release nicotinic acid, extended‑release nicotinic acid, and nicotinamide.
Key Nutrients & Compounds
Provides nicotinic acid and nicotinamide, which are converted to NAD⁺/NADP⁺ to facilitate glycolysis, the Krebs cycle, fatty acid oxidation, and antioxidant regeneration.
Health Benefits
Niacin improves lipid profiles by raising HDL‑cholesterol and lowering triglycerides and LDL‑cholesterol; supports skin and mucosal health; aids DNA repair and cell signaling; and contributes to healthy nervous system function.
Recommended Dosage
The adult RDA is 16 mg NE (niacin equivalents) per day for men and 14 mg NE/day for women. Therapeutic lipid‑modifying doses range from 500 mg to 2,000 mg of nicotinic acid daily, typically in divided doses.
How to Use It
Take niacin with meals to reduce flushing and gastrointestinal upset. Immediate‑release forms may be split into multiple smaller doses; extended‑release formulations should be taken once daily at bedtime to minimize adverse effects.
Who Should Use It?
Individuals with dyslipidemia—particularly low HDL or high triglycerides—under medical supervision; those with pellagra (niacin deficiency); and anyone requiring support for cellular energy metabolism or skin health.
Possible Interactions or Cautions
High‑dose nicotinic acid can cause flushing, itching, liver enzyme elevations, hyperuricemia, and glucose intolerance. Use cautiously with statins due to increased risk of myopathy. Monitor liver function during extended‑release therapy.
Final Thoughts
Niacin is a versatile B vitamin with unique lipid‑modifying and metabolic roles. Dietary intake usually meets requirements, while therapeutic use of nicotinic acid requires careful dosing and monitoring to balance benefits against adverse effects.
Scientific Studies
Canner PL, Berge KG, Wenger NK, et al. Fifteen year mortality in Coronary Drug Project patients: long‑term benefit with niacin. JAMA. 1986;256(14):1725–1734. https://doi.org/10.1001/jama.256.14.1725
Brown BG, Zhao X‑Q, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or both in coronary disease. N Engl J Med. 2001;345(22):1583–1592. https://doi.org/10.1056/NEJMoa011331
Boden WE, Probstfield JL, Anderson T, et al. Niacin in patients with low HDL cholesterol levels receiving intensive statin therapy. N Engl J Med. 2011;365(24):2255–2267. https://doi.org/10.1056/NEJMoa1107579