Niacin vitamin storage

Bioavailability of Niacin. Factors which cause a decrease in macm availability include (1) Cooking losses (2) bound form in corn (maize), greens, and seeds is only partially available (3) presence of oral antibiotics (4) diseases which may cause decreased absorption (5) decrease in tiyptophan conveision as in a vitamin B deficiency. Fac.tois that increase availability include (1) alkali treatment of cereals (2) storage in bver and possibly in muscle and kidney tissue and (3) increased intestinal synthesis. 

Niacin, U5P. Niacin, nicotinic acid, 3-pyridine carboxylic acid, vitamin Bi. iK-curs as white crystals or as a cry.stal-linc powder. It is odorless or may have a slight odor. One gram of nicotinic acid dissolves in 60 mL of water. It is freely soluble in boiling water, boiling alcohol, and solutions of alkali hydroxides and carbonates but is almost insoluble in ether. A % aqueous solution has a pH of 6. Nicotinic acid has a pK of 4.85. Nicotinic acid is stable under normal. storage conditions. It sublimes without decomposition. 

In the first stage of respiration, a six-carbon glucose molecule is split into a pair of three-carbon molecules. Hydrogen Ions and electrons also are produced in glycolysis. These combine with electron carrier ions called nicotinamide adenine dinucleotide (NAD+) to form NADH. NADH is a coenzyme that is made from vitamin B4, which is also called niacin or nicotinic acid. ATP and NADH serve as temporary storage sites for energy and electrons, respectively, during respiration. Two molecules of ATP are used, and four molecules are produced. ... 

Trigonellln 1-methylnicotinic acid, a metabolite of nicotinic acid or nicotinamide found in many plants. It is both a hormone and a storage form of nicotinic acid. It is apparently not a niacin metabolite in animals, although it is found in the urine of coffee drinkers. Green coffee beans contain relatively large (> 500 mg/kg) amounts of X roasting the beans converts T. to nicotinic acid. Coffee is a significant dietary source of niacin (see Vitamins) in South and Central America. 

The best-known functions of niacin are derived from the functions of its coenzymes NAD and NADP in the hydrogen/electron transfer redox reactions in living cells. Like most B vitamins, niacin is not extensively stored in forms or in depots that are usually metabolically inactive, but rather those that can become available during dietary deficiency. However, some storage of the coenzymes NAD and NADP in the liver is thought to occur. An inadequate dietary intake leads rapidly to significant... 

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