Niacin Health Article

Risk factors for deficiency

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 chronic illnesses, liver disease, sprue, or poor nutritional status. People over 55 years old are more likely to have a poor dietary intake. Certain metabolic diseases also increase the requirement for niacin. Those who abuse nicotine, alcohol or other drugs are very frequently deficient in B vitamins, but use of niacin with alcohol can cause seriously low blood pressure. A health care professional can determine if supplementation is appropriate.

Precautions

Niacin should not be taken by anyone with a B vitamin allergy, kidney or liver impairment, severe hypotension, unstable 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.

Side effects

High doses of niacin can cause a harmless, but unpleasant, flushing sensation and darkening of the urine. The "no-flush" form can lessen this complication.

Interactions

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.

KEY TERMS

Antioxidant—Any one of a group of substances which function to destroy cell-damaging free radicals in the body.

Gout—A painful condition of joints, especially the feet and hands, caused by the presence of uric acid crystals.

Myopathy—A disease of muscle tissue.

Sprue—A chronic disease of malabsorption characterized by diarrhea.

BOOKS

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.

Judith Turner