Niacin - Nicotinsäureamid zählt zu den Vitaminen der B-Gruppe
Vorkommen (Lebensmitteltabellen) - viel in Erdnuss, Leber
Bioverfügbarkeit - recht stabiles Vitamin
Indikatoren - Ernährungszustand
Stoffwechsel - Funtionen (Nicotin-Adenin-Dinukleotid) - Redox-System-Coenzyme;
Bedarf -
Mangel -Pellagra
Upper level of intake - Toxizität
Geschichte - 1735 wurde Pellagra in Spanien erstmals beschrieben (Don Gasper Cascal) / Pellagra im Mittelmeerraum (Italien)
1912 - Casimir Funk - Pellagra-preventive factor
1915 - Joseph Goldberger - Epidemiologie - Mexiko_USA - ernährungsbedingte (Vitamin)Mangelkrankheit Pellagra beschrieben
Die Nährstoff- und Energieaufnahmen in Deutschland - in NVS II - Kap. 5.6.3. - Niacin - (S.118)
Niacin (nicotinic acid or nicotinamide) is essential in the form of the coenzymes NAD and NADP in which the nicotinamide moiety acts as electron acceptor or hydrogen donor in many biological redox reactions. NAD functions as an electron carrier for intracellular respiration as well as a codehydrogenase with enzymes involved in the oxidation of fuel molecules. NADP functions as a hydrogen donor in reductive biosyntheses such as in fatty acid and steroid syntheses and, like NAD, as a co-dehydrogenase. NAD, in its only non-redox role, is the substrate for three classes of enzymes that transfer ADP-ribose units to proteins involved in DNA processing, cell differentiation, and cellular calcium mobilization.
Nicotinic acid and nicotinamide are rapidly absorbed from the stomach or the intestine. Nicotinamide, the major form in the bloodstream, arises from enzymatic hydrolysis of NAD(P) in the intestinal mucosa and liver, and is transported to tissues that synthesize their own NAD as needed. Niacin and NAD are biosynthesized from dietary tryptophan via the kynurenine pathway and quinolinic acid. Excess niacin is excreted in the urine primarily as Nl-methylnicotinamide and Nl-methyl-2-pyridone-5-carboxamide.
Deficiencies: Pellagra, the classic niacin deficiency disease, is characterized by bilateral dermatitis, diarrhea, and dementia. Often associated with a largely cereal diet such as maize or sorghum, the disease is now rarely seen in industrialized countries but still appears in India, China, and Africa. Pellagra often is associated with other micronutrient deficiencies and may develop also in cases of disturbed tryptophan metabolism (carcinoid syndrome, Hartnup's).
Diet recommendations: The RDA is expressed in mg niacin equivalents (NE) in which 1 mg NE = 1 mg niacin or 60 mg tryptophan. For individuals above 13 years of age, the 1998 RDA is 16 mg/d for males and 14 mg/d for females, with an additional allowance of 4 mg/d during pregnancy and 3 mg/d during lactation. The RDAs range from 6-12 mg/d for children 1-13 years and 2-3 mg/d for infants to one year.
Food sources: Niacin is widely distributed in plant and animal foods, mainly as the pyridine nucleotides NAD and NADP. Good sources are yeast, meats including liver, cereals, legumes, seeds, milk, green leafy vegetables, and fish.
Clinical uses: Nicotinic acid (but not nicotinamide) given as a drug in doses of 1.5-3 g/d improves the blood cholesterol profile. Nicotinamide acts as a tumor-specific radiosensitizer, possibly due to its effect on vasorelaxation and increased tumor oxygenation.
Toxicity: Large doses of nicotinic acid given to lower cholesterol may produce flushing of the skin, hyperuricemia, and hepatic abnormalities. These effects are reversed if the drug is reduced in amount or discontinued. The 1998 Tolerable Upper Intake Level (UL) of niacin, based on flushing produced by nicotinic acid, is 35 mg/d for adults.
Recent research: Nicotinamide may counteract hepatotoxic effects of alcohol by ameliorating the redox state. Nicotinamide is under investigation for helping prevent and control diabetes.
Lee, J.G et al.: Optical Coherence Tomography, Fluorescein Angiography, and Electroretinography Features of Niacin Maculopathy: New Insight Into Pathogenesis. J VitreoRenal Dis https://doi.org/10.1177/2474126419877567 (01.10.2019) (ref. "Hochdosiertes Vitamin B3 führt zu Augenschäden." link bei www.heilpraxisnet.de 29.10.2019)
For further information:
Jacob, R. A. & Swendseid, M. E. (1996) Niacin, In: Present Knowledge in Nutrition (Ziegler, E. E. & Filer, L. J., eds.), 7th ed., pp. 184-190, International Life Sciences Institute Press, Washington, DC.
http://jn.nutrition.org/nutinfo/content/niac.shtml
DACH -DGE - Niacin - Referenz-Werte
http://www.dge.de/modules.php?name=Content&pa=showpage&pid=4&page=3
Niacin Empfohlene Zufuhr
Alter
Niacin
mg-Äquivalent1/Tag
m w
Säuglinge
0 bis unter 4 Monate2 2
4 bis unter 12 Monate 5
Kinder
1 bis unter 4 Jahre 7
4 bis unter 7 Jahre 10
7 bis unter 10 Jahre 12
10 bis unter 13 Jahre 15 13
13 bis unter 15 Jahre 18 15
Jugendliche und Erwachsene3
15 bis unter 19 Jahre 17 13
19 bis unter 25 Jahre 17 13
25 bis unter 51 Jahre 16 13
51 bis unter 65 Jahre 15 13
65 und älter 13 13
Schwangere
ab 4. Monat 15
Stillende 17
11 mg Niacin-Äquivalent = 60 mg Tryptophan
2Hierbei handelt es sich um einen Schätzwert
3Zugrunde gelegt wurde die entsprechende Tabelle zur Energiezufuhr
Health Claims für Niacin (EFSA Informationen)
ID 43: ―Energy metabolism Nutrient utilisation
iD 44:―Neurological functions
ID 45: ―Normal structure and function of skin and mucous membranes (such as the intestines)
ID 46: ―Blood lipids
ID 48: ―Structure and function of skin
ID 49: ―Macronutrient metabolism
ID 50: ―Bone/Teeth/ Hair / Skin and Nail health
ID 52: ―Skin and mucous membranes
ID 53: ―Neurologic system
ID 54: ―NAD and NADP. These nucleotides are key components of oxidation-reduction reactions, ATP synthetic pathways and ADP-ribose transfer reactions.
ID 55: ―The role of vitamins and minerals in mental performance (where mental performance stands for those aspects of brain and nerve functions which determine aspects like concentration, learning, memory and reasoning)‖
Literaturliste (Datei-Link)
Elmadfa/Leitzmann - Ernährung des Menschen - Ulmer, Stuttgart
http://www.deutschesfachbuch.de/info/detail.php?isbn=3825280365
Übersicht - Verwendung von Vitaminen in Lebensmitteln - Toxikologische und ernährungsphysiologische Aspekte - BfR-Publikation: -Wissenschaft 03/2004)
Mindestbedarf + Höchstmengen an Vitamin A + ß-Karotin; Vitamin D, Vitamin E; Vit K; Vit B1; Vit B2; Niacin; Vit B6, Folsäure, Pantothensäure; Biotin, Vit B12; Vit C (241S)
Pirinen, E. et al.: Niacin Cures Systemic NAD+ Deficiency and Improves Muscle Performance in Adult-Onset Mitochondrial Myopathy. Cell Metabolism doi.org/10.1016/j.cmet.2020.04.008 (07.05.2020) ⇔ "Vitamin B3 revitalizes energy metabolism in muscle disease." link bei www.eurekalert.org 14.05.2020
Niacin - the fountain of youth - ScienceDaily 30.9.13 - Schmeisser, K et al.: Role of sirtuins in lifespan regulation is linked to methylation of nicotinamide. Nature Chemical Biology, 2013; DOI: 10.1038/nchembio.1352 - link
Parkinson: Vitamin B3 (Niacin) hat positive Wirkung auf geschädigte Nervenzellen. idw-Pressemitteilung 2018 ⇒⇒ Schöndorf, D.C. et al.: The NAD+ precursor, nicotinamide riboside, rescues mitochondrial defects and neuronal loss in iPSC and fly models of Parkinson’s disease. Cell Reports 23(10) doi: 10.1016/j.celrep.2018.05.009 (2018)
Robert A Jacob, ME Swendseid: Niacin - Chap.19 - Present Knowledge of Nutrition. ILSI, 1990 (6.Aufl) (gibt aktuell - 9.Auflage, 2006
http://www.ilsi.org/NR/rdonlyres/D57D78BA-AE2C-430F-9B77-7077FD63D95F/0/PKN9TOC.pdf
http://history.nih.gov/exhibits/Goldberger/index.html
en.wikipedia.org/wiki/Joseph_Goldberger
http://de.wikipedia.org/wiki/Niacin
http://www.answers.com/topic/niacin
Kamala S. Jaya Rao: Commentary: Pellagra in sorghum eaters: A mycotoxicosis? Ecol Food Nutr 13(1) 59-62 (1983)
US Dietary Reference Intakes - The Essential Guide to Nutrient Requirements (NAS, 2006) (free download at National Academic Press) S.262-269
