B A S I C I N F O R M A T I O N

 

Formally identified as a B-complex vitamin, niacin exists in two forms: nicotinic acid and nicotinamide. [This (niacin) nitrogen heterocyclic biochemical is combined in vivo with the nucleotide adenosine to form nicotinamide adenine dinucleotide (NAD)] The active coenzyme form of this vitamin is called NAD+/H and NADP+/H (nicotinamide adenine dinucleotide and nicotinamide adenine dinucleotide phosphate).

Niacin can be found within the human body in the liver, brain, kidneys, and even blood cells. It can also be found in different meats, eggs, cereals, whole grains, avocadoes, peanuts, fish, milk, and soybeans.

Niacin can also be synthesized with tryptophan, an amino acid. 60 milligrams of Trp equates 1 milligram of niacin (1 NE). However, for such synthesis to occur, there must be a sufficient level of pyridoxine (vitamin B6) and riboflavin to catalyze the reaction. High fat diets tend to suppress the trp to niacin conversion.

Note: its main inhibitor is an antivitamin called

NAD/NADP is involved in many different reactions within our body. Its involved in the following:

 

 

1. Transportation of certain nutrients. It can act as an active soluable, electron carrier in biochemical reactions.

2. Metabolism of carbohydrates, fats, and porteins

3. cell respiration

4. proper functioning of the nervous and circulatory system.

5. synthesis of hormones, fatty acids, and steroids.

6. regulatation of cholesterol and building of red blood cells.

 

R E S E A R C H

Thursday, November 29, 2001 - 12:00 a.m. Pacific Heart trouble reduced in study: Drug-niacin mix may reverse disease. Combining a cholesterol-lowering drug with the vitamin niacin can reduce some patients' risk of heart attack, stroke and hospitalization for chest pain by about 70 percent, University of Washington researchers have found in a new study of patients with cardiovascular disease.

The new research showed that adding niacin to simvastatin, sold under the brand name Zocor, is a dramatic improvement. The combination both stops the narrowing of coronary arteries Ñ even slightly reducing the blockage Ñ and reduces the risk of fatal and nonfatal heart attacks, strokes and procedures for chest pain by a range of 60 to 90 percent.

http://seattletimes.nwsource.com/html/localnews/134372326_heart29m0.html

Studies of cultured cells in vitro provide evidence that NAD content influences the cellular response to DNA damage, an important risk factor for cancer. Cellular NAD is consumed in the synthesis of ADP-ribose polymers, which play a role in DNA repair, and cyclic ADP-ribose may mediate cell-signaling pathways important in the prevention of cancer (see Function). Additionally, cellular NAD content has been found to influence levels of the tumor suppressor protein, p53, in human breast, skin, and lung cells.
Jacobson, E.L. et al. Mapping the role of NAD metabolism in prevention and treatment of carcinogenesis. Molecular and Cellular Biochemistry. 1999; volume 193: pages 69-74. (PubMed)

More recently, nicotinic acid supplementation of up to 100 mg/day in 21 healthy smokers failed to provide any evidence of a decrease in cigarette smoke-induced genetic damage in blood lymphocytes compared to placebo.

Jacobson E. Niacin deficiency and cancer in women. Journal of the American College of Nutrition. 1993; volume 12: pages 412-416. (PubMed)

Recently, a large case control study found increased consumption of niacin, along with antioxidant nutrients, to be associated with decreased incidence of oral, pharyngeal, and esophageal cancers in northern Italy and Switzerland.

Negri, E. Selected micronutrients and oral and pharyngeal cancer. International Journal of Cancer. 2000; volume 86: pages 122-127. (PubMed)

Franceschi, S. Role of macronutrients, vitamins, and minerals in the aetiology of squamous-cell carcinoma of the oesophagus. International Journal of Cancer. 2000; volume 86: pages 626-631. (PubMed)

http://www.orst.edu/dept/lpi/infocenter/vitamins/niacin/niacin.html#ref10

 

 

D E F I C I E N C Y ... L E A D S T O . .

<--- NICOTINIC ACID

60 MG TRYPTOPHAN = 1 MILLIGRAM OF NIACIN

 

At the bottom is a picture of NAD/NADH. This active coenzyme uses its oxidative/reductive ability in many biochemical reactions.

 

At the bottom is a picture of NADP/NADPH. This other active coenzyme form differs from NAD/NADP because of an additional phosphate. As we can see, its name parallels its structure to a great extent.