A report on Niacin

A man with pellagra, which is caused by a chronic lack of vitamin B3 in the diet
Niacin, serotonin (5-hydroxytryptamine), and melatonin biosynthesis from tryptophan
Inositol hexanicotinate
Space-filling model of niacin

Organic compound and a form of vitamin B3, an essential human nutrient.

- Niacin
A man with pellagra, which is caused by a chronic lack of vitamin B3 in the diet

49 related topics with Alpha

Overall
The skin features of pellagra including peeling, redness, scaling, and thickening of sun-exposed areas.

Pellagra

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The skin features of pellagra including peeling, redness, scaling, and thickening of sun-exposed areas.
This child has the casal collar skin rash around the neck associated with pellagra.
Man with pellagra with typical skin lesions
Dr. Joseph Goldberger

Pellagra is a disease caused by a lack of the vitamin niacin (vitamin B3).

The redox reactions of nicotinamide adenine dinucleotide.

Nicotinamide adenine dinucleotide

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Coenzyme central to metabolism.

Coenzyme central to metabolism.

The redox reactions of nicotinamide adenine dinucleotide.
UV absorption spectra of NAD and NADH.
Some metabolic pathways that synthesize and consume NAD in vertebrates. The abbreviations are defined in the text.
Salvage pathways use three precursors for NAD+.
Rossmann fold in part of the lactate dehydrogenase of Cryptosporidium parvum, showing NAD in red, beta sheets in yellow, and alpha helices in purple.
In this diagram, the hydride acceptor C4 carbon is shown at the top. When the nicotinamide ring lies in the plane of the page with the carboxy-amide to the right, as shown, the hydride donor lies either "above" or "below" the plane of the page. If "above" hydride transfer is class A, if "below" hydride transfer is class B.
A simplified outline of redox metabolism, showing how NAD and NADH link the citric acid cycle and oxidative phosphorylation.
The structure of cyclic ADP-ribose.
Arthur Harden, co-discoverer of NAD

In organisms, NAD can be synthesized from simple building-blocks (de novo) from either tryptophan or aspartic acid, each a case of an amino acid; alternatively, more complex components of the coenzymes are taken up from nutritive compounds such as niacin; similar compounds are produced by reactions that break down the structure of NAD, providing a salvage pathway that “recycles” them back into their respective active form.

A bottle of B-complex vitamin pills

Vitamin

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Organic molecule that is an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism.

Organic molecule that is an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism.

A bottle of B-complex vitamin pills
Calcium combined with vitamin D (as calciferol) supplement tablets with fillers.
Jack Drummond's single-paragraph article in 1920 which provided structure and nomenclature used today for vitamins

Some sources list fourteen vitamins, by including choline, but major health organizations list thirteen: vitamin A (as all-trans-retinol, all-trans-retinyl-esters, as well as all-trans-beta-carotene and other provitamin A carotenoids), vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B7 (biotin), vitamin B9 (folic acid or folate), vitamin B12 (cobalamins), vitamin C (ascorbic acid), vitamin D (calciferols), vitamin E (tocopherols and tocotrienols), and vitamin K (phylloquinone and menaquinones).

Nicotinamide

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Form of vitamin B3 found in food and used as a dietary supplement and medication.

Form of vitamin B3 found in food and used as a dietary supplement and medication.

NAD+, the oxidized form of NADH, contains the nicotinamide moiety (highlighted in red)
The active Nicotinamide group on the molecule NAD+ undergoes oxidation in many metabolic pathways.

While nicotinic acid (niacin) may be used for this purpose, niacinamide has the benefit of not causing skin flushing.

Lovastatin, a compound isolated from Aspergillus terreus, was the first statin to be marketed.

Statin

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Statins, also known as HMG-CoA reductase inhibitors, are a class of lipid-lowering medications that reduce illness and mortality in those who are at high risk of cardiovascular disease.

Statins, also known as HMG-CoA reductase inhibitors, are a class of lipid-lowering medications that reduce illness and mortality in those who are at high risk of cardiovascular disease.

Lovastatin, a compound isolated from Aspergillus terreus, was the first statin to be marketed.
Atorvastatin bound to HMG-CoA reductase: PDB entry
The HMG-CoA reductase pathway, which is blocked by statins via inhibiting the rate limiting enzyme HMG-CoA reductase.
The oyster mushroom, a culinary mushroom, naturally contains lovastatin.

They have less effect than the fibrates or niacin in reducing triglycerides and raising HDL-cholesterol ("good cholesterol").

Chemical structure

Riboflavin

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Vitamin found in food and sold as a dietary supplement.

Vitamin found in food and sold as a dietary supplement.

Chemical structure
Cultures of Micrococcus luteus growing on pyridine (left) and succinic acid (right). The pyridine culture has turned yellow from the accumulation of riboflavin.

The coenzymes are also required for the metabolism of niacin, vitamin B6, and folate.

An 1836 lithograph of tortilla production in rural Mexico

Nixtamalization

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Process for the preparation of corn, or other grain, in which the grain is soaked and cooked in an alkaline solution, usually limewater , washed, and then hulled.

Process for the preparation of corn, or other grain, in which the grain is soaked and cooked in an alkaline solution, usually limewater , washed, and then hulled.

An 1836 lithograph of tortilla production in rural Mexico
Dried, treated maize sold in Oaxaca, Mexico (US quarter and Mexican peso shown for scale)
Dry maize, untreated (left) and boiled in lime (right). In this case, typical of El Salvador, a pound of maize (454 g) is boiled with a tablespoon of lime (15 mL) for 15 minutes, left to stand for a few hours, and washed with fresh water. The hulls are removed, and the kernels ground into masa. Exact methods vary by use and region.
Flowchart of the nixtamalization process.

Corn's hemicellulose-bound niacin is converted to free niacin (a form of vitamin B3), making it available for absorption into the body, thus helping to prevent pellagra.

Metabolism of -tryptophan into serotonin and melatonin (left) and niacin (right). Transformed functional groups after each chemical reaction are highlighted in red.

Tryptophan

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An α-amino acid that is used in the biosynthesis of proteins.

An α-amino acid that is used in the biosynthesis of proteins.

Metabolism of -tryptophan into serotonin and melatonin (left) and niacin (right). Transformed functional groups after each chemical reaction are highlighted in red.

Tryptophan is also a precursor to the neurotransmitter serotonin, the hormone melatonin, and vitamin B3.

A 4-ml sample of hyperlipidemic blood in a vacutainer with EDTA. Left to settle for four hours without centrifugation, the lipids separated into the top fraction.

Hyperlipidemia

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Abnormally elevated levels of any or all lipids or lipoproteins in the blood.

Abnormally elevated levels of any or all lipids or lipoproteins in the blood.

A 4-ml sample of hyperlipidemic blood in a vacutainer with EDTA. Left to settle for four hours without centrifugation, the lipids separated into the top fraction.
Relative prevalence of familial forms of hyperlipoproteinemia

Treatment include diet control, fibrates and niacins.

Vitamin B3

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Vitamin B3 is a vitamin family that includes three forms or vitamers: nicotinamide (niacinamide), niacin (nicotinic acid), and nicotinamide riboside.