Synonyms/Common Names/Related Substances:

• 2-pyridone, 3-pyridine carboxamide, acipimox (5-methylpyrazinecarboxylic acid 4-oxide), acipomox, Acipimox®, anti-blacktongue factor, antipellagra factor, B vitamin, B-complex vitamin, benicot, B-vitamin, chromium polynicotinate (niacin-bound chromium), coenzyme beta-nicotinamide adenine dinucleotide (NAD(+)), crystalline niacin, dihydropyridines, Efacin®, Endur-Acin® (sustained release niacin (nicotinic acid)), Enduramide®, ER niacin, esters of niacin, extended-release (ER) niacin, extended-release (ER) niacin monotherapy, extended-release (ER) niacin therapy, Hexopal®, immediate-release (crystalline) niacin, immediate-release niacin, inositol hexaniacinate, inositol hexanicotinate, inositol nicotinate, kynurenine (KYN), low-dose sustained-release nicotinic acid (Tri-B3), meso-inositol hexanicotinate, methyl niacinamide, Nature's Bounty® Flush Free Niacin Inositol Hexanicotinate 500mg Dietary Supplement, NIAC®, niacin, niacin (nicotinic acid), niacin equivalents, niacin ER, niacinamide, niacinamide adenine dinucleotide (NAD), niacinamide adenine dinucleotide phosphate (NADP), niacin/colestipol therapy, Niacor®, Niaspan® (prolonged-release nicotinic acid), Niaspan® (sustained-release nicotinic acid), Nicalex®, nicamid, Nicamin®, Nicangin®, Niceritrol, Nico-400®, Nicobid® (sustained-released niacin), Nicobid® (time-release niacin), Nicolar® (unmodified niacin), nicosedine, Nico-Span®, nicotinamide, nicotinamide (niacinamide), Nicotinamide cures, nicotinate, Nicotinex®, nicotinic acid, nicotinic acid adenine, nicotinic acid adenine dinucleotide phosphate (NAADP), nicotinic acid amide, nicotinic acid analog (low plasma free fatty acid trial, LFA), nicotinic acid analogue, nicotinic amide, nicotinuric acid, nicotylamidum, nutrient supplements, Papulex®, pellagra preventing factor, pentaerythritoltetranicotinate, perycit, prolonged-release (PR) nicotinic acid (niacine)[Niaspan®], pyridine-3-carboxylic acid, Slo-Niacin® (sustained-release niacin), sustained-release nicotinic acid (Nico-Span®), Tega-Span®, Tri-B3®, trigonelline, tryptophan, vitamin B-3, vitamin B3, vitamin B3 (nicotinamide), vitamin B3 derivative, vitamin-B complex (vit-B), Wampocap®, wax-matrix sustained release niacin, wax-matrix sustained-release niacin (Endur-Acin®).
• Combination product examples: ADVICOR® (niacin extended-release/lovastatin tablets), Cordaptive^TM (niacin/laropiprant).

Clinical Bottom Line/Effectiveness

Brief Background:

• Vitamin B3 is composed of niacin (nicotinic acid) and its amide, niacinamide, and can be found in many foods, including yeast, meat, fish, milk, eggs, green vegetables, and cereal grains. Dietary tryptophan, found in protein-containing foods such as red meat, poultry, eggs, and dairy products, is also converted to niacin after ingestion. Vitamin B3 is frequently found in combination with other B vitamins, including thiamine, riboflavin, pantothenic acid, pyridoxine, cyanocobalamin, and folic acid.
• Based on numerous clinical trials, niacin (not niacinamide) appears to be a relatively safe, inexpensive, and effective treatment for hyperlipidemia. Niacin supplementation is a lipid-modifying therapy that specifically addresses the triglyceride/high-density lipoprotein cholesterol axis (1). Niacin is also a widely used lipid-regulating agent in dyslipidemic patients (2). Niacin elicits significant increases in HDL, up to 30% at doses ranging from 1-1.5g daily, with greater effects than other drugs (including 3-hydroxy 3-methylglutarylCoA; HMG-CoA reductase inhibitors/statins). Niacin also causes mild reductions (~5-20%) in low-density lipoproteins (LDL), with stronger effects occurring at higher doses (3-4.5g daily). Additional decreases in LDL levels can be achieved by combining niacin with an HMG-CoA reductase inhibitor or bile acid sequestrant. Preliminary evidence suggests that niacin therapy may reduce the incidence of atherosclerosis and secondary cardiovascular events (3). Niacin decreases lipoprotein (a) and fibrinogen levels; both have been associated with a decreased risk of coronary artery disease (4;​5;​6). However, niacin therapy has also been found to increase plasma homocysteine levels by up to 55% (7;​8), possibly negating any positive effects on serum lipids and increasing the risk of adverse cardiac events.
• Niacinamide (not niacin) has been investigated for the prevention and delay of type 1 diabetes mellitus, possibly mediated through the protection and preservation of pancreatic β-islet cell function. Initial human research has been equivocal. Preliminary evidence suggests potential for niacinamide as a treatment for osteoarthritis.
• Niacin therapy has a high incidence of initial minor adverse events, including cutaneous flushing, pruritus, and gastrointestinal upset (9;​10;​11;​12;​13;​14;​15;​16;​17;​18;​19;​20;​21;​22;​23). Numerous case reports have been published concerning the development of hepatotoxicity following niacin therapy, ranging from elevated aminotransferase levels to jaundice, ascites, and hepatitis (18;​24;​25;​26;​27;​28;​29;​30;​31;​32;​33;​34;​35;​36;​37;​38;​39;​40;​41;​42;​43;​44;​45;​45;​46;​47;​48;​49;​50). Concomitant use of niacin or niacinamide and other agents that elevate transaminases or elicit hepatotoxicity may have additive hepatotoxic effects. Both niacin and HMG-CoA reductase inhibitors may elevate liver function tests or result in hepatotoxicity, and transaminase levels should be monitored. Immediate-release nicotinic acid may pose less risk of hepatotoxicity than extended-release formulations. Niacin, particularly in large doses, may cause insulin resistance, hyperglycemia, and hyperinsulinemia (11;​12;​15;​16;​19;​24;​26;​29;​51;​52;​53;​54;​55;​56;​57;​58;​59;​60;​61;​62;​63;​64;​65;​66;​67;​68;​69). Skin rash, headache, transient low blood pressure, altered thyroid hormone levels, and elevated blood levels of uric acid have also been noted with nicotinic acid therapy.
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Dosing/Toxicology

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Precautions/Contraindications

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Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

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Mechanism of Action

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History

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Evidence Table

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Evidence Discussion

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Products Studied

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Author Information

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References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

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