Vitamin B3

Last Updated: September 28 2022

Niacin is an essential B-vitamin. Supplementation results in improved cholesterol and triglyceride levels. However, since a side-effect of supplementation is increased insulin resistance, niacin supplementation only provides benefits for cardiovascular health if precautions are taken.

Vitamin B3 is most often used for


Vitamin B3 refers to the molecule commonly called nicotinic acid, or niacin, though it may also refer to the other vitamin B3 vitamer, called nicotinamide. Vitamin B3 is necessary to support the function of many enzymes.

Niacin supplementation is very effective at normalizing blood lipid levels. Supplementation increases HDL-C levels and decreases LDL-C and triglyceride levels. This makes niacin look like a great cardioprotective supplement on paper. Unfortunately, niacin supplementation does not reliably result in a reduced risk of cardiovascular disease, possibly because it also increases insulin resistance, which could negate the benefits niacin provides for blood lipid levels.

Niacin supplementation is theorized to benefit cognition and longevity. This is because niacin supplementation increases cellular nicotinamide adenine dinucleotide (NAD+) levels. Preliminary evidence suggests increased NAD+ levels may result in the above benefits, but much more research is needed to determine if this effect actually occurs.

Topical application of nicotinamide is sometimes used for skin health, though it is not as effective as vitamin A. Nicotinamide is used for topical application because it does not result in the flushed skin that niacin supplementation can cause.

Current evidence suggests prolonged niacin supplementation increases insulin resistance because it hinders the ability of insulin to suppress glucose synthesis in the liver. This causes an increase in blood glucose levels, which leads to lowered insulin sensitivity over time, since the relevant receptor is eventually desensitized to the elevated glucose levels in the blood.

The flush caused by niacin supplementation is a temporary effect. Though it may be uncomfortable, it is not harmful. There are many case studies describing people overdosing on niacin in an effort to pass a urine test. Niacin overdose results in multiple organ failure and is not effective at masking a urine test.

What else is Vitamin B3 known as?
Note that Vitamin B3 is also known as:
  • Niacin
  • B3
  • Vitamin B3
Vitamin B3 should not be confused with:
Dosage information

Most of the benefits from niacin supplementation occur after doses of at least one gram. This is approximately 5,000% the recommended daily intake.

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3.^Sauve AANAD+ and vitamin B3: from metabolism to therapiesJ Pharmacol Exp Ther.(2008 Mar)
4.^Sauve AA1, Youn DYSirtuins: NAD(+)-dependent deacetylase mechanism and regulationCurr Opin Chem Biol.(2012 Dec)
5.^Kurnasov O1, Goral V, Colabroy K, Gerdes S, Anantha S, Osterman A, Begley TPNAD biosynthesis: identification of the tryptophan to quinolinate pathway in bacteriaChem Biol.(2003 Dec)
6.^Fukuwatari T1, Ohta M, Kimtjra N, Sasaki R, Shibata KConversion ratio of tryptophan to niacin in Japanese women fed a purified diet conforming to the Japanese Dietary Reference IntakesJ Nutr Sci Vitaminol (Tokyo).(2004 Dec)
8.^Yang H1, Lavu S, Sinclair DANampt/PBEF/Visfatin: a regulator of mammalian health and longevityExp Gerontol.(2006 Aug)
9.^Pieper JAUnderstanding niacin formulationsAm J Manag Care.(2002 Sep)
11.^Benyó Z1, Gille A, Kero J, Csiky M, Suchánková MC, Nüsing RM, Moers A, Pfeffer K, Offermanns SGPR109A (PUMA-G/HM74A) mediates nicotinic acid-induced flushingJ Clin Invest.(2005 Dec)
12.^Soudijn W1, van Wijngaarden I, Ijzerman APNicotinic acid receptor subtypes and their ligandsMed Res Rev.(2007 May)
13.^Cantó C1, Houtkooper RH, Pirinen E, Youn DY, Oosterveer MH, Cen Y, Fernandez-Marcos PJ, Yamamoto H, Andreux PA, Cettour-Rose P, Gademann K, Rinsch C, Schoonjans K, Sauve AA, Auwerx JThe NAD(+) precursor nicotinamide riboside enhances oxidative metabolism and protects against high-fat diet-induced obesityCell Metab.(2012 Jun 6)
19.^MacKay D1, Hathcock J, Guarneri ENiacin: chemical forms, bioavailability, and health effectsNutr Rev.(2012 Jun)
23.^Kruse W, Kruse W, Raetzer H, Heuck CC, Oster P, Schellenberg B, Schlierf GNocturnal inhibition of lipolysis in man by nicotinic acid and derivativesEur J Clin Pharmacol.(1979 Aug)
25.^Wise A1, Foord SM, Fraser NJ, Barnes AA, Elshourbagy N, Eilert M, Ignar DM, Murdock PR, Steplewski K, Green A, Brown AJ, Dowell SJ, Szekeres PG, Hassall DG, Marshall FH, Wilson S, Pike NBMolecular identification of high and low affinity receptors for nicotinic acidJ Biol Chem.(2003 Mar 14)
26.^Soga T1, Kamohara M, Takasaki J, Matsumoto S, Saito T, Ohishi T, Hiyama H, Matsuo A, Matsushime H, Furuichi KMolecular identification of nicotinic acid receptorBiochem Biophys Res Commun.(2003 Mar 28)
27.^Lorenzen A1, Stannek C, Burmeister A, Kalvinsh I, Schwabe UG protein-coupled receptor for nicotinic acid in mouse macrophagesBiochem Pharmacol.(2002 Aug 15)
28.^Singh N1, Gurav A2, Sivaprakasam S2, Brady E2, Padia R2, Shi H3, Thangaraju M3, Prasad PD3, Manicassamy S4, Munn DH5, Lee JR6, Offermanns S7, Ganapathy V8Activation of Gpr109a, receptor for ni