Niacin

Niacin (also known as vitamin B3, nicotinic acid and vitamin PP) is an organic compound with the formula C6H5NO2 and, depending on the definition used, one of the forty to eighty essential human nutrients.

Niacin is one of five vitamins (when lacking in human diet) associated with a pandemic deficiency disease: niacin deficiency (pellagra), vitamin C deficiency (scurvy), thiamin deficiency (beriberi), vitamin D deficiency (rickets), vitamin A deficiency (night blindness and other symptoms). Niacin has been used for over 50 years to increase levels of HDL in the blood and has been found to modestly decrease the risk of cardiovascular events in a number of controlled human trials .

This colorless, water-soluble solid is a derivative of pyridine, with a carboxyl group (COOH) at the 3-position. Other forms of vitamin B3 include the corresponding amide, nicotinamide ("niacinamide"), where the carboxyl group has been replaced by a carboxamide group (CONH2), as well as more complex amides and a variety of esters.

Niacin cannot be directly converted to nicotinamide, but both compounds could be converted to NAD and NADP in vivo. Although the two are identical in their vitamin activity, nicotinamide does not have the same pharmacological effects (lipid modifying effects) as niacin. Nicotinamide does not reduce cholesterol or cause flushing. Nicotinamide may be toxic to the liver at doses exceeding 3 g/day for adults. Niacin is a precursor to NAD+/NADH and NADP+/NADPH, which play essential metabolic roles in living cells. Niacin is involved in both DNA repair, and the production of steroid hormones in the adrenal gland.

Read more about Niacin:  Dietary Needs, Deficiency, Lipid-modifying Effects, Toxicity, Nicotinamide, Inositol Hexanicotinate, Biosynthesis and Chemical Synthesis, Receptor, Food Sources, History, Research

Other articles related to "niacin":

Niacin - Research
... As of August 2008, a combination of niacin with laropiprant is being tested in a clinical trial ... Laropiprant reduces facial flushes induced by niacin ...
Akotin - Inositol Hexanicotinate
... (IHN), which is inositol that has been esterified with niacin on all six of inositol's alcohol groups ... is usually sold as "flush-free" or "no-flush" niacin in units of 250, 500, or 1000 mg/tablets or capsules ... over-the-counter formulation, and often is marketed and labeled as niacin, thus misleading consumers into thinking they are getting the active form of the medication ...
Laropiprant
... Laropiprant (INN) is used in combination with niacin to reduce blood cholesterol (LDL and VLDL) ... Both brands contain 1000 mg of niacin and 20 mg of laropiprant in each tablet ... Laropiprant itself has no cholesterol lowering effect, but it reduces facial flushes induced by niacin ...
Akotin - History
... Niacin was first described by chemist Hugo Weidel in 1873 in his studies of nicotine ... Niacin was extracted from livers by biochemist Conrad Elvehjem in 1937, who later identified the active ingredient, then referred to as the "pellagra-preventing ... to dissociate it from nicotine, to avoid the perception that vitamins or niacin-rich food contains nicotine, or that cigarettes contain vitamins ...
Akotin - Toxicity
... Pharmacological doses of niacin (1.5 - 6 g per day) lead to side effects that can include dermatological conditions such as skin flushing and itching, dry skin, and ... Some of these symptoms are generally related to niacin's role as the rate limiting cofactor in the histidine decarboxylase enzyme which converts l-histidine into histamine ... and can be blocked by taking 300 mg of aspirin half an hour before taking niacin, by taking one tablet of ibuprofen per day or by co-administering the prostaglandin receptor antagonist ...