The designation vitamin B3, whose chemical formula is C5H4NCOOH (or alternatively, C6H6NO2), also includes the corresponding amide nicotinamide, or niacinamide, whose chemical formula is C6H6N2O.
The main problem with the clinical use of niacin for dyslipidemia is the occurrence of skin flushing, even with moderate doses (NLM and NIH 2005).
Alkali lime releases the tryptophan from the corn so that it can be absorbed in the gut and converted to niacin (UMMC 2004).
Biosynthesis of niacin from tryptophan requires both vitamin B6 and riboflavin.
Studies in laboratory animals have demonstrated behavioral changes when large doses of niacin are given (Sullivan 1958).
The resulting name 'niacin' was derived from nicotinic acid + vitamin.
Severe lack of niacin causes the deficiency disease pellagra, whereas a mild deficiency slows down the metabolism decreasing cold tolerance.
Niacin is one of the B vitamins (vitamin B complex), a group of chemically distinct, water-soluble vitamins that also includes thiamine, riboflavin, pantothenic acid, biotin, pyridoxine, folic acid, and others.
Niacin refers to both nicotinic acid and nicotinamide.
The conversion of niacin to NAD and NADP, and the use of these coenzymes in intricate biological processes like the citric acid cycle, reveals the complex coordination in living organisms.
Niacin is licensed as a food coloring agent in some countries.
Niacin is found in meat, fish, nuts, green vegetables, and yeast, among other sources.
NAD (and niacin) may also be synthesized in the liver from the amino acid tryptophan (Hidgon 2002).
Niacin, also known as nicotinic acid or vitamin B3, is a vitamin whose derivatives NAD, NADH, NAD+, and NADP play essential roles in energy metabolism in the living cell and DNA repair.
The liver can synthesize niacin from the essential amino acid tryptophan, but the synthesis is extremely slow; 60 milligrams of tryptophan are required to make one milligram of niacin (Higdon 2002).
Niacin plays an important role in the production of several sex and stress-related hormones, particularly those made by the adrenal gland.
Dietary niacin deficiency has been prominent historically in areas where people eat corn, a grain that is low in niacin, as a staple food, and that don't use lime during maize (corn) meal/flour production.
Niacin in itself is not toxic, but the chemicals converted by niacin are toxic to the skin and liver in overdose, and high doses of niacin should only be reached with gradual increase.
Many enzymes require niacin coenzymes NAD and NADP.
Extremely high doses of niacin can cause niacin maculopathy, a thickening of the macula and retina, which leads to blurred vision and blindness (Gass 1973).