Niacin (nicotinic acid) is a water-soluble, B vitamin that gets excreted from the body every day. Also known as vitamin B3, niacin is available as niacinamide (nicotinamide), and inositol hexanicotinate. Niacin is one of eight B vitamins.
B-complex vitmains help the body process fats and protein and maintain nervous system function. They support healthy eyes, hair, skin, and liver, and aids circulation. On top of that, niacin has a hand in producing sex and stress hormones.
Water-soluble vitaminBecause it's a water-soluble vitamin, consuming foods that contain vitamin B is the only way replenish levels each day. Due to food availability and a diverse diet, niacin deficiency is rare in North America.
Niacin helps lower LDL "bad" cholesterol and triglycerides, but it can cause side effects -- specifically when taken in high doses and used long-term -- such as stomach aches, headaches, dizziness, blurred vision, and increased risk of liver damage. Niacin can interfere with medications that lower cholesterol.
Taking niacin may lead to reduced risk of developing cardiovascular problems, such as angina, stroke, and heart attack, especially when taken with conventional medications. Evidence that vitamin B3 is an effective treatment for heart disease is lacking.
Vitamin B6 may have beneficial effects on tension and migraine headaches. The mechanism of action has yet to be identified.
Possibly effective in reducing symptoms of cholera (a type of infection), such as diarrhea.
Helps manage diabetes.
Reduces symptoms of bullous pemphigoid, a skin disorder that causes blistering.
Reduces symptoms of granuloma annulare, a skin disease characterized by reddish bumps, often arranged in a circle.
Promotes skin health.
This is a type of vitamin B3 created when niacin and inositol are combined. Inositol is a simple carbohydrate that is used to balance certain chemicals in the body. It may help regulate panic disorders, depression, obsessive compulsive disorder (OCD), and polycystic ovary syndrome (PCOS).
Inositol nicotinate is mainly used to help improve blood circulation, reduce blood cholesterol, and reduce high blood pressure.
Niacin and niacinamide
The possible benefits of vitamin B3 are:
For treatment of Alzheimer's disease - dietary niacin may reduce symptoms of Alzheimer's disease.
Managing osteoarthritis - niacinamide may reduce pain and swelling and improve joint flexibility.
Improve symptoms of atherosclerosis - vitamin B3 may improve blood vessel health and reduce the risk of developing atherosclerosis (hardening of the blood vessels).
Diabetes treatment: vitamin B3 may help manage type 1 and type 2 diabetes.
Pellagra is a disorder caused by niacin deficiency. Here are some situations or conditions that can cause a niacin deficiency:
Low intake of dietary niacin
Gastrointestinal diseases, such as diarrhea and colitis
Low intake tryptophan, an amino acid in meat, poultry, fish, and eggs
Pellagra is characterized by the 4 D's: diarrhea, dermatitis, dementia, and death. Niacin deficiency is rare in the U.S., although binge drinkers and alcoholics are at higher risk.
Niacin deficiency is rare in the U.S., although binge drinkers and alcoholics are at higher risk.
A doctor can prescribe oral niacinamide to patients diagnosed with the deficiency.
Recommended doseRecommended daily allowance (RDA) for vitamin B.
|Birth to 6 months||0.1mg*||0.1mg*|
* Adequate Intake (AI)
Oral vitamin B3 supplements and dietary sources are safe for most people. However, some minor side effects have been reported.
Flushing - vasodilation of blood vessels, especially the capillaries found beneath the skin, causing redness and a sensation of warmth. Flushing is caused by niacin - not niacinamide. Alcohol is known to worsen flushing.
Pain caused by intestinal bloating or gas
Allergy outbreaks may occur more frequently since vitamin B3 is known to increase histamine production.
There are reports that more than 3g of niacin and niacinamide may cause serious side effects:
Gout, caused by decreased excretion of uric acid
Irregular heart rate
Increased risk of stroke
Rice: 0.1mg per serving and 5% of daily value (DV)
Cottage cheese: 1 cup of low-fat cottage cheese contains 0.2mg per serving and 10% DV.
Ground beef: Broiled, 85% lean ground beef contains 0.3mg of niacin per serving and 15% DV.
Lean meat (pork, beef, and veal)
Lamb liver: 3oz. of pan fried lamb liver contains 0.9mg of vitamin B6 per serving and 45% DV.
Paprika: 1 tbsp contains 5% DV of niacin, or 0.1mg per serving
Tuna and salmon: 3oz. cooked yellowfin tuna and sockeye salmon contains 0.9mg B6 per serving and 45% DV.
Enriched foods, such as bread and cereals
Legumes (peanuts): 1 cup of peanuts have 0.5mg of vitamin B6, 25% of the DV.
Nuts (almonds, macadamia, and cashews): 1oz. dry-roasted mixed nuts have 0.1mg per serving and 5% DV.
Seeds: 1 tbsp of sesame seeds has 0.1mg of vitamin B6, 5% of DV.
Pumpkin seeds: 1 cup of pumpkin seeds contain 0.2mg of niacin and 10% of the DV.
Foods like bread, cereal, and milk are fortified with extra vitamins and minerals.
Food and drug interactions
Vitamin B3 may cause problems when taken with certain foods or drugs. Talk to your doctor before taking a new vitamin or supplement.
Kombucha tea: This medicinal fermented tea is thought to reduce the absorption of niacin, which can lead to developing pellagra. More studies are needed to uncover how kombucha tea and vitamin B3 interact.
Hepatotoxic herbs and supplements
Niacin may cause liver problems, especially at doses higher than 3g. The following herbs and supplements have possible hepatotoxic effects (may damage liver cells) and should be taken with caution when you're taking large doses of vitamin B3, especially the niacin form.
DHEA or dehydroepiandrosterone
Avoid drinking alcohol when taking niacin supplements. Beer, wine, and liquor may increase certain side effects, such as flushing and pruritus (itching).
These are drugs that prevent gout by lowering uric acid levels in the blood. Large doses of niacin have been known to decrease excretion of uric acid, which may render a uricosuric, like allopurinol and probeneceid, ineffective.
High doses and long-term use of niacin and niacinamide may cause insulin resistance and production of glucose in the liver, which can interfere with drugs prescribed for the treatment of diabetes.
Some people use this anti-hypertensive drug to reduce facial flushing. However, when combined, niacin and clonidine may cause orthostatic hypotension (a drop in blood pressure) when you suddenly stand or sit upright.
Consult your doctor before taking any form of vitamin B3, especially if you're on OTC or prescription medications. Also, research the possible side effects of combining B-complex with other vitamins and supplements.
- MedlinePlus; Niacin. 2011
- MedlinePlus; Niacin and Niacinamide (Vitamin B3); Natural Medicines Comprehensive Database
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- Mayo Clinic; "Niacin to boost your HDL, 'good,' cholesterol"
- AIM-HIGH Investigators, Boden WE, et. al; NEJM; "Niacin in patients with low HDL cholesterol levels receiving intensive statin therapy;" 2011
- McKenney J.; Archives of Internal Medicine; "New perspectives on the use of niacin in the treatment of lipid disorders;" 2004
- Niacinamide - Compound Summary
- WebMD; Inostidol
- WebMD; Inositol Nicotinate
- Morris MC, et. al; Journal of Neurology, Neurosurgery, and Psychiatry; Dietary niacin and the risk of incident Alzheimer's disease and of cognitive decline;" 2004
- MedlinePlus; Pellagra
- Hegyi J, et. al; International Journal of Dermatology; "Pellagra: dermatitis, dementia, and diarrhea;" 2004
- Fuller F.; Orthomolecular Vitamin Information Centre Inc.; "Niacin Flush or Vasodilatation"
- University of Maryland Medical Center; " Vitamin B3 (Niacin);" 2011
- Prousky J., et. al. Journal of Nutrition;" The treatment of migraines and tension-type headaches with intravenous and oral niacin (nicotinic acid): systematic review of the literature;" 2005
- National Institutes of Health; Office of Dietary Supplements; Vitamin B6