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The Eclectic Physician
Vitamin and Mineral Information
Vitamin B-3/ Niacin or Niacinamide
The information on this page compiled by
Beth Burch N.D.
Index
(click on the keywords)
Function
Vitamin B-3 or niacin is a component of two enzymes,
NAD and NADH, which function in many chemical reactions in the body. These
enzymes are vital in the production of energy from carbohydrates, for the
synthesis of fatty acids and the sex and adrenal hormones, as well as the
regulation of cholesterol and triglyceride metabolism. Niacin can be made
by the body from the amino acid tryptophan. Deficiency of vitamin B-3 and/or
tryptophan in the diet results in the disease, pellagra. Pellagra is characterized
by various types of dermatitis including redness and blistering, maceration
and infection of the skin folds, thickened, pigmented, inelastic skin over
pressure points and/or dry scaly skin. The mucous membranes are also affected
in pellagra with bright red swollen tongue, sore mouth and throat, and
inflammation of the vagina. Nausea, vomiting and diarrhea may occur. Pellagra
also affects the brain, causing poor memory, confusion, depression, mania,
and abnormal reflexes. Deficiency is common where co rn is the staple of
the diet, and is also seen in alcoholics, in liver disease, chronic diarrhea,
carcinoid tumors and Hartnup’s disease. Prolonged treatment with the anti-tuberculosis
medication, isoniazid, can result in pellagra. Extensive research has shown
that niacin is effective for reducing elevated cholesterol and triglyceride
levels and is even being used in combination with other cholesterol lowering
medications.
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Forms
-
Vitamin B-3 is available in supplements in two basic forms- niacin (nicotinic
acid) and niacinamide. Niacin has cholesterol lowering and vasodilating
effects, but can result in uncomfortable side effects like skin flushing
and burning. Niacinamide does not lower cholesterol levels. A type of niacin
known as inositol hexaniacinate is effective for lowering cholesterol without
the skin flushing. Timed release niacin has been associated with an increased
risk of liver damage and should not be used.
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Food Sources
-
Vitamin B-3 is especially high in meat, eggs, fish, peanuts, nutritional
yeast, rice bran and wheat bran. Good sources include legumes, whole grains
(except corn) and dairy products. Vitamin B-3 is heat stable.
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Dosage
-
Recommended Daily Allowance (RDA)
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Infants- 5-6 mg
-
Children (ages 1-10)- 9-13 mg
-
Adults- 13-20 mg
-
Pregnancy- 17 mg
-
Lactation- 20 mg
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Optimal Supplementation
Treatment
of Health Conditions
-
300-3000 mg daily. Niacin or niacinamide is used depending on the health
condition. Dosages over 1000 mg per day should only be used with a doctor’s
supervision and with frequent blood tests of liver enzymes and glucose
levels.
Conditions used
for
-
Elevated cholesterol and/or triglyceride levels- use niacin (1,4)
-
Raynaud’s disease- use inositol hexaniacinate
(5)
-
Recent onset insulin dependent diabetes- use niacinamide (3)
-
Arthritis- use niacinamide (2)
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Side effects
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As little as 50 mg of niacin can cause flushing, headache and stomach upset
-
Doses of over 1000 mg of either niacin or niacinamide can cause liver damage,
gastritis, impaired glucose tolerance and elevated uric acid levels
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Contraindications
-
Liver disease, peptic ulcer, severe low blood pressure, gout or diabetes
-
Hypersensitivity to niacin or niacinamide products
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Interactions
with other nutrients
-
Works together with other B vitamins to produce energy from carbohydrates
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Interactions
with medications and herbs
-
May potentiate the effects of beta blockers like propanolol
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References
1. Guyton JR, Effect of niacin on atherosclerotic cardiovascular
disease, Am J Cardiol 1998;82(12A):18U-23U; discussion 39U-41U
2. Jonas WB et al, The effect of niacinamide on osteoarthritis: a pilot
study, Inflamm Res 1996;45(7):330-4
3. Visalli N et al, A multi-centre randomized trial of two different
doses of nicotinamide in patients with recent-onset type 1 diabetes (the
IMDIAB VI), Diabetes Metab Res Rev 1999;15(3):181-5
4. Canner PL et al, Fifteen year mortality in Coronary Drug Project
patients: Long-term benefit with niacin, J Am Coll Cardiol 1986;8:1245-55
5. Sunderland GT et al, A double blind randomized placebo controlled
trial of hepaxol in primary Raynaud’s disease, Clin Rheumatol 1988;7:46-49
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* The information presented in this web site is intended to inform and educate.
It is not intended replace a qualified medical practitioner to diagnose or treat medical conditions.
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