niacin


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Related to niacin: pantothenic acid, niacin deficiency

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.

nic·o·tin·ic ac·id

(nik'ō-tin'ik as'id),
Part of the vitamin B complex; used in the prevention and treatment of pellagra, as a vasodilator, and in hyperlipidemia, in which it lowers cholesterol and acts an agent to elevate levels of high-density lipoprotein.

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.

niacin

(nī′ə-sĭn)
n.
A white crystalline acid, C6H5NO2, of the vitamin B complex that is found in meat, fish, legumes, and whole-grain foods and is used to treat and prevent pellagra. Also called nicotinic acid.

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.

niacin

A water-soluble “B-complex” vitamin integrated in the coenzyme nicotinamide adenine dinucleotide (NAD), an H+ acceptor for dehydrogenases which is formed in the body from tryptophan; it has been used in management of alcoholism, migraines, and to improve lipid profiles.
 
Deficiency
Anorexia, glossitis, headaches, insomnia, rash, depression, pseudodementia.
 
Toxicity
Skin flushing, arrhythmias, defects in glucose and urea metabolism, diarrhoea, nausea, gastric bleeding, headaches, itching, hepatic toxicity, psychotic reactions.

Normal
> 2.5 mg/24 hour in urine.

Sources
High-protein foods—e.g., fish, poultry, meats, liver, yeast, enriched bread, cereals.

Niacin decreased the risks of CAD by improving the lipid profile: decreased LDL-C by 15%, decreased TGs by 30%, decreased Apo B by 16%, decreased Lp(1) by 25%, and increased HDL-C by 20%; it is believed by some alternative health advocates to be useful for anxiety, arthritis, autism, depression, DM, hypoglycemia, and schizophrenia.

nic·o·tin·ic ac·id

(nik'ō-tin'ik as'id)
A part of the vitamin B3 complex; used in the prevention and treatment of pellagra, as a vasodilator, and as an HDL-raising agent; taken by some people in erroneous idea it will hide drug use in urine tests; such use can elicit GI complaints, dizziness, and loss of consciousness.
Synonym(s): niacin.

niacin

Nicotinamide, one of the B group of vitamins. Nicotinic acid. Niacin is present in liver, meat, grains and legumes. It is a constituent of coenzymes involved in oxidation-reduction reactions. Deficiency causes PELLAGRA. Niacin is being used in the treatment of high blood cholesterol levels. The drug is on the WHO official list.

niacin

see NICOTINIC ACID.

niacin

one of the vitamin B complex. vitamin B3 refers also to nicotinic acid and nicotinamide. See also vitamins; appendix 4.2 .

nicotinic acid

; niacin part of vitamin B complex; used as a dietary supplement to prevent pellagra; also acts as vasodilatory agent and lowers blood cholesterol

niacin,

n See vitamin B3.

nic·o·tin·ic ac·id

(nik'ō-tin'ik as'id)
A part of the vitamin B3 complex; used in the prevention and treatment of pellagra, as a vasodilator, and as an agent to increase levels of high-density lipoproteins.
Synonym(s): niacin.

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.

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.

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).
References in periodicals archive ?
The study compared over 25,000 patients treated with either niacin along with laropiprant, or placebo.
The goal was to determine whether raising the HDL level with niacin would prevent major coronary events, stroke of any type, or revascularization procedures.
Even after the initial report, more than 700,000 prescriptions for various niacin drugs were given ever month in U.
Some of the side effect information, including a troubling rise in deaths among niacin users in one study, also was known but many doctors have been waiting for full details and verification of the results before drawing firm conclusions about the drug's safety and effectiveness.
Tablets utilize a distinctive polygel controlled-release system that gradually delivers nicotinic acid into the body and is designed to reduce the likelihood of flushing commonly associated with immediate-release niacin use.
Niacin microspheres were prepared by the chemical denaturation method.
When the Oxford researchers first saw the preliminary results from the HPS2-THRIVE study, they contacted the Principal Investigators of the AIM-HIGH trial which had tested the effects of adding extended-release niacin (Niaspan) alone on top of statin-based treatment.
Indeed, the combination drug used in the study -- made by US pharmaceutical giant and combining extended release niacin with laropiprant -- is already approved in 70 countries, though not the US.
Our case of a patient on extended release niacin revealed dramatic reversible decreases in hepatic clotting factors, lipoproteins, and other proteins, without elevation of hepatic enzymes or overt hepatic injury.
As expected, niacin raised HDL and lowered triglycerides.
They have now started an early trial to see if a slow-release form of niacin benefits stroke patients.