Niacin (Vitamin B-3),
Be aware that the U.S. Food and Drug Administration does not strictly
regulate herbs and dietary supplements. There is no guarantee of strength,
purity or safety of products containing or claiming to contain niacin. Decisions
to use herbs or supplements should be carefully considered. Individuals using
prescription drugs should discuss taking herbs or supplements with a pharmacist
or health care professional before starting.
Vitamin B-3 is composed of niacin (nicotinic acid) and is a source of
niacinamide. Scientists have studied niacin for the following health problems:
Niacin has been observed to have substantial benefits in lowering high
cholesterol levels. It is particularly effective in raising levels of
high-density lipoprotein (HDL or "good cholesterol") levels, but it is less
effective at lowering low-density lipoprotein (LDL or "bad cholesterol")
levels than some other cholesterol-lowering drugs. Niacin is currently used
as one of the first-line treatments of high cholesterol either alone or in
combination with other cholesterol-lowering drugs. Niacinamide, which is
also present in vitamin B-3, does not have the same effects as niacin on
cholesterol levels. Some studies show that niacin can raise homocysteine
levels, which may increase the risk of cardiovascular disease.
Pellagra (niacin deficiency)
Pellagra is a disease caused by niacin deficiency. Symptoms of pellagra include
skin irritation, diarrhea, dementia or depression. The disease may affect
chronic abusers of alcohol. However, diabetes, liver disease, pregnancy and
some drugs may also cause niacin deficiency. Both niacin and niacinamide
are approved by the U.S. Food and Drug Administration for treating niacin
Atherosclerosis (clogged arteries), prevention of heart disease
Niacin has been shown to lower cholesterol levels. Lower cholesterol has
been associated with slowing the progression of clogged arteries, and unclogged
arteries lessen the risk of heart disease. However, niacin has also been
shown to increase the levels of homocysteine, a compound in the blood that
increases the risk of clogged arteries.
Scientific evidence from studies in humans supports the use of niacin in
combination with other drugs to reduce the risk of clogged arteries in people
with high cholesterol. However, more research is needed to determine whether
niacin can reduce clogged arteries and prevent heart disease and death when
it is used alone.
Niacinamide, a chemical in vitamin B-3, has been proposed as a possible therapy
to prevent diabetes or delay the need for insulin. Animal studies of niacinamide
use in diabetes have suggested that it may increase the time that oral drug
treatment is effective and delay the need for insulin injections. Research
in humans has shown mixed results with niacinamide, and most studies had
flaws in their designs. More research is needed to determine if niacinamide
provides any advantages in delaying or preventing the onset of insulin dependence
in individuals with diabetes.
The use of niacin for the treatment of dyslipidemia associated with type
2 diabetes has been controversial because of the possibility of worsening
glycemic control. However, a recent randomized, controlled, multicenter trial
showed that of 148 patients in the study, only four discontinued because
of inadequate glucose control. These researchers reported doses of 1,000
to 1,500 milligrams per day (in a controlled-release formulation) to be a
treatment option for type 2 diabetics with dyslipidemia. Check with your
physician and pharmacist before starting niacin.
Results from one study suggest that niacinamide, a chemical in vitamin B-3,
may help to improve flexibility, reduce inflammation and lessen the need
for drugs that are commonly used for pain in people with osteoarthritis.
The study was small, and more research is needed to determine if niacinamide
provides benefits for this condition.
Alzheimer's disease, cognitive decline
Dementia can be caused by severe niacin insufficiency, but it is unknown
whether variation in intake of niacin in the usual diet is linked to
neurodegenerative decline. One large, prospective study examined whether
dietary intake of niacin was associated with incident Alzheimer's disease
and cognitive decline. The authors concluded that dietary niacin may protect
against Alzheimer's disease and age-related cognitive decline. Further research
is needed to confirm these results.
Niacin has been suggested for many other uses, based on tradition or on
scientific theories. However, these uses have not been thoroughly studied
in humans, and there is limited scientific evidence about safety or
effectiveness. Some of these suggested uses are for conditions that are
potentially very serious and even life-threatening. You should consult a
health care professional before taking niacin for any unproven use.
Age-related macular degeneration
Chemotherapy side effects
High blood pressure
HIV treatment and prevention
Ischemic injury prevention
Low blood sugar levels
Non-ST-segment elevation acute coronary syndromes
Peripheral vascular disease
Ringing in the ears
Taste disturbance (diminished/distorted sense of taste)
People should avoid niacin/vitamin B-3 if they have a known allergy to niacin
or niacinamide. Anaphylactic shock (a severe allergic reaction) has occurred.
Signs of allergy may include rash, itching or shortness of breath.
Niacin has been associated with many minor side effects. Some people may
experience flushing, itching and stomach discomfort, including stomachache,
nausea, vomiting and diarrhea. Niacin may also aggravate peptic ulcer disease.
Most stomach-related side effects usually go away over time. Taking niacin
with food may prevent stomach discomfort.
Flushing or a warm sensation, especially on the face, neck and ears, occurs
in almost all patients using niacin for the first time or at higher doses.
This side effect usually goes away on its own after one or two weeks. Using
aspirin or other nonsteroidal anti-inflammatory drugs such as ibuprofen can
reduce the tingling, itching, flushing and warmth associated with niacin.
Slow-release niacin formulations may have a lower incidence of flushing but
may also be more likely to cause stomach upset and liver abnormalities.
Other possible side effects include headache, dizziness, panic attacks, anxiety,
difficulty breathing, irregular heartbeats and dental pain. Macular edema
and blurred vision have also been reported. Niacin may also damage the liver.
Periodic monitoring of liver function by a qualified health care professional
is recommended. If you develop yellow skin or eyes or have pain in your abdomen,
it is a good idea to contact a health care professional.
Niacin increases blood sugar levels, which can be a concern for patients
with diabetes and dyslipidemia. Theoretically, this could cause decreased
glycemic control. However, a recent randomized, controlled, multicenter trial
showed that of 148 patients in the study, only four discontinued because
of inadequate glucose control. Doses of 1,000 to 1,500 milligrams per day
(in a controlled-release formulation) were shown to be a treatment option
for type 2 diabetics in this study. If you take drugs by mouth or use insulin
to control your blood sugar levels and are considering using niacin, increased
monitoring is necessary because doses of diabetic drugs may need to be adjusted.
Ketones and sugar may be detected in the urine. Uric acid in the blood is
increased and can aggravate or cause gouty attacks. Thyroid function may
also be impaired while taking niacin. Periodic monitoring of thyroid function
is recommended. If you take drugs to treat thyroid disease and are considering
using niacin, discuss this with a health care professional.
Other rare side effects reported in people using niacin are alterations in
some blood cell counts, muscle pain and degeneration and metabolic abnormalities
such as metabolic acidosis. Niacin may also increase the risk of bleeding.
If you use anticoagulants (blood thinners) or antiplatelet drugs and are
considering using niacin, discuss this with a health care professional. You
may be advised to stop using niacin before some surgeries. Anaphylactic shock
(a severe allergic reaction) from severe niacin allergies may also occur.
Pregnancy And Breast-Feeding
Niacin cannot be recommended during pregnancy and breast-feeding because
of a lack of information.
Interactions with drugs, herbs and other supplements have not necessarily
been thoroughly studied. The interactions listed below have been reported
in scientific publications. If you are taking prescription drugs, speak with
a health care professional or pharmacist before using herbs or dietary
Interactions With Drugs
When niacin is used with other cholesterol-lowering drugs, such as clofibrate,
probucol, gemfibrozil (Lopid), cholestyramine (Questran), colestipol (Colestid)
and lovastatin (Mevacor), the combination of drugs may result in greater
lowering of cholesterol. However, when niacin is used with cholestyramine
or colestipol, the drug may prevent niacin from being maximally effective,
and when niacin is used with drugs such as lovastatin or gemfibrozil, there
may be an increased risk of muscle degeneration. Combining neomycin with
niacin may lower cholesterol levels more than niacin alone. Using niacin
and nicotine together may increase some side effects such as flushing and
dizziness. It is possible that birth control pills may enhance the activities
of niacin, and lower niacin doses may be needed.
Some drugs may reduce the effectiveness of niacin. Examples include antibiotics,
isoniazid and pantothenic acid. Niacin may increase the effects and toxicity
of some drugs such as diazepam (Valium), carbamazepine (Tegretol), valproate
(Depakote, Depakene), griseofulvin, estrogens, progestins, testosterone and
atracurium. Some of these possible drug interactions have been studied only
in laboratory settings, and the significance in humans is not known.
Niacin has been shown to increase blood sugar levels. Dosing adjustments
may be needed for insulin or oral diabetes drugs. Niacin may also alter thyroid
hormone levels, requiring larger doses of thyroid drugs. Vitamin B-6 (pyridoxine)
and zinc sulfate may alter the metabolism of niacin, but the significance
is unclear. Niacin may increase the risk of bleeding when used with
anticoagulants (blood thinners) or antiplatelet drugs. Examples include warfarin
(Coumadin), heparin and clopidogrel (Plavix). Some pain relievers may also
increase the risk of bleeding if used with niacin. Examples include aspirin,
ibuprofen (Motrin, Advil) and naproxen (Naprosyn, Aleve, Anaprox).
Interactions With Herbs And Dietary Supplements
Use of niacin with chromium polynicotinate, sitosterols and
seed proanthocyanidin may cause greater cholesterol-lowering effects
than any of the agents used alone. However, some research suggests that the
use of niacin with antioxidants may slightly decrease the cardiovascular
benefits of niacin. More studies are needed in this area. Because niacin
alters thyroid hormone levels, it should be used carefully with other supplements
that affect thyroid hormone levels, such as bladderwrack.
In theory, niacin may increase the risk of bleeding when taken with other
products that are also believed to increase the risk of bleeding. Examples
(Allium sativum). When niacin is used with herbs such as borage,
or uva ursi, there may be an increased risk of liver toxicity. Niacin has
been shown to increase blood sugar levels and may decrease the blood
sugar-lowering properties of herbs such as
melon. Combining niacin with vitamin A and vitamin E may lower cholesterol
levels more than niacin alone.
The doses listed below are based on scientific research, publications
or traditional use. Because most herbs and supplements have not been thoroughly
studied or monitored, safety and effectiveness may not be proven. Brands
may be made differently, with variable ingredients even within the same brand.
Combination products often contain small amounts of each ingredient and may
not be effective. Appropriate dosing should be discussed with a health care
professional before starting therapy; always read the recommendations on
a product's label. The dosing for unproven uses should be approached cautiously,
because scientific information is limited in these areas.
The recommended daily dietary intake of niacin ranges from 16 to 35 milligrams.
Taking niacin supplements with food may reduce the likelihood of stomach
upset. Doses are usually started low and increased slowly to minimize flushing,
although aspirin or ibuprofen may reduce the flushing adverse effect.
Adults (Aged 18 Or Older)
By mouth: Doses used in studies for treating high cholesterol range
from 300 to 3,000 milligrams of immediate-release (crystalline) niacin daily
(divided into two or three doses) or from 500 to 2,000 milligrams of
sustained-release niacin. Doses are usually started lower and increased
gradually. When treating pellagra (niacin deficiency), doses between 50 and
1,000 milligrams daily have been used. Studies have used one to four grams
of niacin daily for treating clogged arteries or heart disease or 200 to
3,000 milligrams of niacinamide daily to delay insulin dependence in diabetes.
Children (Younger Than 18): There are not enough scientific data to
recommend niacin for use in children, and niacin is not recommended because
of potential side effects. Note that there are concerns about the lack of
evidence regarding treatment of childhood lipid disorders, including the
long-term psychological and metabolic effects. At this time, diet alteration
is acceptable first-line treatment, without the use of lipid-lowing drugs,
until adulthood is reached.
Vitamin B-3 is composed of niacin (nicotinic acid) and is a source of
niacinamide. Niacin and niacinamide have been suggested as treatments for
many conditions. There is scientific support for the use of niacin in lowering
total cholesterol and low-density lipoprotein (LDL or "bad cholesterol")
levels and in raising levels of high-density lipoprotein (HDL or "good
cholesterol"). Niacin is also a well-established treatment for pellagra (niacin
deficiency). There is some evidence that niacin may provide benefits for
clogged arteries and may prevent heart disease. There is not enough scientific
evidence to support the use of niacin or niacinamide for any other medical
Niacin may cause many adverse effects, including flushing, headache, dizziness
and itching. Niacin may also raise blood sugar levels, alter thyroid hormone
levels, increase uric acid levels and cause liver damage. Therefore, niacin
should be used carefully in people with diabetes, thyroid disease, gout and
liver disease. It should also be avoided in pregnant or breast-feeding women
and in children. Niacin may increase the risk of bleeding. Consult a health
care professional immediately if you have any side effects.
The information in this monograph was prepared by the professional staff
at Natural Standard, based on thorough systematic review of scientific evidence.
The material was reviewed by the Faculty of the Harvard Medical School with
final editing approved by Natural Standard.
Standard: An organization that produces scientifically based reviews
of complementary and alternative medicine (CAM) topics
for Complementary and Alternative Medicine (NCCAM): A division of the
U.S. Department of Health & Human Services dedicated to research
Selected Scientific Studies: Niacin
Natural Standard reviewed more than 775 articles to prepare the professional
monograph from which this version was created.
Some of the more recent studies are listed below:
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type 2 diabetes mellitus, and familial combined hyperlipidemia. Am J Cardiol
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Ballantyne CM, Corsini A, Davidson MH, et al. Risk for myopathy with statin
therapy in high-risk patients. Arch Intern Med 2003;Mar 10, 163(5):553-564.
Comment in: Arch Intern Med 2003;Jul 14, 163(13):1615-1616. Author reply,
Bays HE, Dujovne CA, McGovern ME, et al. ADvicor Versus Other
Cholesterol-modulating Agents Trial Evaluation: comparison of once-daily,
niacin extended-release/lovastatin with standard doses of atorvastatin and
simvastatin (the ADvicor Versus Other Cholesterol-Modulating Agents Trial
Evaluation [ADVOCATE]). Am J Cardiol 2003;Mar 15, 91(6):667-672.
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cardiac transplant recipients. Am Heart J 2004;Aug, 148(2):200-210.
Birjmohun RS, Hutten BA, Kastelein JJ, Stroes ES. Efficacy and safety of
high-density lipoprotein cholesterol-increasing compounds: a meta-analysis
of randomized controlled trials. J Am Coll Cardiol 2005;Jan 18, 45(2):185-197.
Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins,
or the combination for the prevention of coronary disease. N Engl J Med
Bucher HC, Griffith LE, Guyatt GH. Systematic review on the risk and benefit
of different cholesterol-lowering interventions. Arterioscler Thromb Vasc
Canner PL, Furberg CD, Terrin ML, McGovern ME. Benefits of niacin by glycemic
status in patients with healed myocardial infarction (from the Coronary Drug
Project). Am J Cardiol 2005;Jan 15, 95(2):254-257.
Capuzzi DM, Morgan JM, Carey CM, et al. Rosuvastatin alone or with
extended-release niacin: a new therapeutic option for patients with combined
hyperlipidemia. Prev Cardiol 2004;Fall, 7(4):176-181.
Capuzzi DM, Morgan JM, Weiss RJ, et al. Beneficial effects of rosuvastatin
alone and in combination with extended-release niacin in patients with a
combined hyperlipidemia and low high-density lipoprotein cholesterol levels.
Am J Cardiol 2003;Jun 1, 91(11):1304-1310.
Cheung MC, Zhao XQ, Chait A, et al. Antioxidant supplements block the response
of HDL to simvastatin-niacin therapy in patients with coronary artery disease
and low HDL. Arterioscler Thromb Vasc Biol 2001;21(8):1320-1326.
Elam MB, Hunninghake DB, Davis KB, et al. Effect of niacin on lipid and
lipoprotein levels and glycemic control in patients with diabetes and peripheral
arterial disease: the ADMIT study. A randomized trial: Arterial Disease Multiple
Intervention Trial. JAMA 2000;284(10):1263-1270.
Gerber MT, Mondy KE, Yarasheski KE, et al. Niacin in HIV-infected individuals
with hyperlipidemia receiving potent antiretroviral therapy. Clin Infect
Dis 2004;Aug 1, 39(3):419-425. Epub 2004;Jul 16.
Goldberg AC. A meta-analysis of randomized controlled studies on the effects
of extended-release niacin in women. Am J Cardiol 2004;Jul 1, 94(1):121-124.
Goldberg A, Alagona P Jr, Capuzzi DM, et al. Multiple-dose efficacy and safety
of an extended-release form of niacin in the management of hyperlipidemia.
Am J Cardiol 2000;85(9):1100-1105.
Goldstein MR. Use of niacin during non-ST-segment elevation acute coronary
syndromes. JAMA 2005;May 4, 293(17):2092-2093. Author reply, 2093.
Grundy SM, Vega GL, McGovern ME, et al. Diabetes Multicenter Research Group:
efficacy, safety, and tolerability of once-daily niacin for the treatment
of dyslipidemia associated with type 2 diabetes. Results of the assessment
of diabetes control and evaluation of the efficacy of niaspan trial. Arch
Intern Med 2002;162(14):1568-1576.
Guyton JR, Capuzzi DM. Treatment of hyperlipidemia with combined niacin-statin
regimens. Am J Cardiol 1998;82(12A):82U-84U.
Guyton JR, Goldberg AC, Kreisberg RA, et al. Effectiveness of once-nightly
dosing of extended-release niacin alone and in combination for
hypercholesterolemia. Am J Cardiol 1998;82(6):737-743.
Guyton JR, Blazing MA, Hagar J, et al. Extended-release niacin vs. gemfibrozil
for the treatment of low levels of high-density lipoprotein cholesterol:
Niaspan-Gemfibrozil Study Group. Arch Intern Med 2000;160(8):1177-1184.
Hannan F, Davoren P. Use of nicotinic acid in the management of recurrent
hypoglycemic episodes in diabetes. Diabetes Care 2001;24(7):1301.
Kashyap ML, McGovern ME, Berra K, et al. Long-term safety and efficacy of
a once-daily niacin/lovastatin formulation for patients with dyslipidemia.
Am J Cardiol 2002;89(6):672-678.
Komaroff AL. By the way, doctor: my CRP was 4 in April and rose to 5 in June.
I've taken niacin to lower my LDL: it didn't work for that, but did increase
my HDL and lower my triglycerides. My question: besides taking a statin,
what can I do to lower my CRP? Harv Health Lett 2005;Jan, 30(3):8.
McKenney JM, McCormick LS, Schaefer EJ, et al. Effect of niacin and atorvastatin
on lipoprotein subclasses in patients with atherogenic dyslipidemia. Am J
Morris MC, Evans DA, Bienias JL, et al. Dietary niacin and the risk of incident
Alzheimer's disease and of cognitive decline. J Neurol Neurosurg Psychiatry
Pozzilli P, Browne PD, Kolb H. Meta-analysis of nicotinamide treatment in
patients with recent-onset IDDM: The Nicotinamide Trialists. Diabetes Care
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drug therapies: implications for treatment. Ann Intern Med 1996;125(12):990-1000.
Sprecher DL. Raising high-density lipoprotein cholesterol with niacin and
fibrates: a comparative review. Am J Cardiol 2000;86(12A):46L-50L.
Taylor AJ, Sullenberger LE, Lee HJ, et al. Arterial Biology for the Investigation
of the Treatment Effects of Reducing Cholesterol (ARBITER) 2: a double-blind,
placebo-controlled study of extended-release niacin on atherosclerosis
progression in secondary prevention patients treated with statins. Circulation
2004;Dec 7, 110(23):3512-3517. Epub 2004;Nov 10.
Whitney EJ, Krasuski RA, Personius BE, et al. A randomized trial of a strategy
for increasing high-density lipoprotein cholesterol levels: effects on
progression of coronary heart disease and clinical events. Ann Intern Med
2005;Jan 18, 142(2):95-104.
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triglyceride concentrations in prevention of coronary heart disease in Type
2 diabetes. Diabet Med 2004;Sep, 21(Suppl 4):8-11.
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lipoprotein in patients undergoing long-term statin therapy. Am Heart J
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when added sequentially to a statin for treatment of dyslipidemia. Am J Cardiol
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Last updated July 14, 2005