A serious deficiency of niacin causes a condition called pellagra. Once quite common in all countries, it has become rare outside of areas in which poor nutrition is still the norm. Affected groups include refugees displaced by war as well as populations affected by such emergency situations as famine. The symptoms of pellagra include dermatitis, dementia, and diarrhea.
Milder deficiencies of niacin can cause similar, but less severe symptoms. Dermatitis, especially around the mouth, and other rashes may occur, along with fatigue, irritability, poor appetite, indigestion, diarrhea, headache, and possibly delirium.
Severe niacin deficiency is uncommon in most parts of the world, but some people may need more than the RDA in order to maintain good health. Vegans, and others who do not eat animal protein, should consider taking a balanced B vitamin supplement. Others that may need extra niacin and other B vitamins may include people under high stress, including those experiencing
Niacin should not be taken by anyone with a B vitamin allergy, kidney or liver impairment, severe hypotension, un-stable angina, arterial hemorrhage, or coronary artery disease. Supplemental niacin can exacerbate peptic ulcers. Diabetics should use caution as supplements of either niacin or niacinamide can alter medication requirements to control blood glucose. Supplements can raise uric acid levels, and aggravate gout in people with this condition. Pregnant women should not take high doses of niacin, or any supplement, except on the advice of a health care provider.
Health care should be sought immediately if certain symptoms occur following niacin supplementation. These include abdominal pain, diarrhea, nausea, vomiting, yellowing of the skin, faintness, or headache. Such symptoms may indicate excessively low blood pressure or liver problems. Heart palpitations and elevated blood sugar are also potential effects.
High doses of niacin can cause a harmless but un-pleasant flushing sensation as well as darkening of the urine. The "no-flush" form can lessen this complication.
Niacin supplements should not be taken by anyone on medication for high blood pressure, due to the potential for hypotension. Isoniazid, a drug used to treat tuberculosis, inhibits the body's ability to make niacin from tryptophan. Extra niacin may be required. Supplements may also be needed by women taking oral contraceptives. Concomitant use of niacin with statin class drugs to lower cholesterol can cause myopathy. Cholestyramine and cholestipol, older medications to lower cholesterol, should be taken at a different time than niacin or they will reduce its absorption. Transdermal nicotine used with niacin is likely to cause flushing and dizziness. Carbamazepine, an antiseizure medication, is more likely to cause toxicity in combination with niacin.
Bratman, Steven, and David Kroll. Natural Health Bible. Prima Publishing, 1999.
Griffith, H. Winter. Vitamins, Herbs, Minerals & supplements: the complete guide. Arizona: Fisher Books, 1998.
Jellin, Jeff, Forrest Batz, and Kathy Hitchens. Pharmacist's letter/Prescriber's Letter Natural Medicines Comprehensive Database. California: Therapeutic Research Faculty, 1999.
Pressman, Alan H., and Sheila Buff. The Complete Idiot's Guide to Vitamins and Minerals. New York: alpha books, 1997.
Batiste, M. C., and E. J. Schaefer. "Diagnosis and Management of Lipoprotein Abnormalities." Nutrition in Clinical Care: An Official Publication of Tufts University 5 (May-June 2002): 115-123.
Gotto, A. M. Jr. "Management of Dyslipidemia." American Journal of Medicine 112 (June 3, 2002) (Supplement 8A): 10S-18S.
Hopkins, P. M. "Familial Hypercholesterolemia." Curren Treatment OPtions in Cardiovascular Medicine 4 (April 2002): 121-128.
Prinzo, Z. W., Z. W. Prinzo, and D. Benoist. "Meeting the Challenges of Micronutrient Deficiencies in Emergency-Affected Populations." Proceedings of the Nutrition Society 61 (May 2002): 251-257.
Troppmann, L., K. Gray-Donald, and T. Johns. "Supplement Use: Is There Any Nutritional benefit?" Journal of the American Dietetic Association 102 (June 2002): 818-825.
American Dietetic Association. 216 West Jackson Blvd., Chicago, IL 60606. (312) 899-0040. <www.eatright.org>.
World Health Organization (WHO). Avenue Appia 20, 1211 Geneva 27, Switzerland. (+41 22) 791-2111. <www.who.int>.
Judith Turner
Rebecca J. Frey, PhD
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Author Info: Judith Turner, Rebecca J. Frey PhD, The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Alternative Medicine, 2005 |