niacin

niacin /ni·a·cin/ (ni´ah-sin) nicotinic acid; a water-soluble vitamin of the B complex required by the body for the formation of the coenzymes NAD and NADP, important in biochemical oxidations; used to prevent and treat pellagra and to treat hyperlipidemia.

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ni·a·cin (n-sn)

n.

A crystalline acid that is a component of the vitamin B complex and is used to treat and prevent pellagra. Also called nicotinic acid.

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niacin

[nī′əsin]

a white, crystalline, water-soluble vitamin of the B complex, usually occurring in various plant and animal tissues as nicotinamide. It functions as a coenzyme necessary for the breakdown and use of all major nutrients and is essential for a healthy skin, normal functioning of the GI tract, maintenance of the nervous system, and synthesis of the sex hormones. It may be used therapeutically to help reduce high blood cholesterol levels. Rich dietary sources of both niacin and its precursor tryptophan are meats, poultry, fish, liver, kidney, eggs, nuts, peanut butter, brewer's yeast, and wheat germ. Symptoms of deficiency include muscular weakness, general fatigue, loss of appetite, various skin eruptions, halitosis, stomatitis, insomnia, irritability, nausea, vomiting, recurring headaches, tender gums, tension, and depression. Severe deficiency results in pellagra. The vitamin is not stored in the body, and daily sources are needed. Niacin toxicity is associated with large doses of nicotinic acid (may occur with a dose as low as 50 to 100 mg). Symptoms include flushing, nausea, dizziness, diarrhea, abdominal pain, and alteration of glucose tolerance. Overdose can also exacerbate preexisting conditions such as cardiac arrhythmias and abnormal liver function. Also called nicotinic acid. See also pellagra.

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niacin [ni´ah-sin]

a water-soluble vitamin of the B complex (see vitamin), found in various animal and plant tissues, especially liver, yeast, bran, peanuts, lean meats, fish, and poultry. A well balanced diet usually supplies more than the daily requirement. It is required by the body for the synthesis of the coenzymes NAD and NADP, which are required for many oxidation-reduction reactions. Deficiency of niacin produces pellagra, and administration of niacin is used to prevent and treat that condition. It is also used to treat hyperlipidemia. Called also nicotinic acid.

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niacin,

n See vitamin B₃.

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niacin (vitamin B

n brand name: generic niacin (nicotinic acid);
drug class: vitamin B₃;
action: needed for conversion of fats, protein, carbohydrates by oxidation-reduction; acts directly on vascular smooth muscle, causing vasodilation;
uses: pellagra, hyperlipidemias, peripheral vascular disease.

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niacin

a water-soluble vitamin of the B complex found in various animal and plant tissues. Essential for normal carbohydrate metabolism. Most natural animal feeds have high enough content to avoid need for supplementation, except for pigs fed a heavy corn diet. Called also nicotinic acid, vitamin PP. See also nicotinamide.

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niacin nutritional deficiency

causes hemorrhagic diarrhea, dermatitis, anemia and a severe stomatitis with ulceration of the mouth and tongue ('black tongue'). In cats, the signs are diarrhea, emaciation and death. Called also pellagra.

niacin production

a test for differentiating Mycobacteria tuberculosis (positive) and M. avium (negative).