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26 Cards in this Set
- Front
- Back
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What are the two molecules that make up niacin?
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Nicotinic acid and nicotinamide
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What are the best sources of niacin in foods? Serving/amount?
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Chicken: 7mg/serving
Tuna: 11 mg/serving |
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Where can niacin be synthesized in the body?
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In the liver and some tissues
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How can NAD+ be biosynthesized in the liver?
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from tryptophan.
*Accounts for 1/2 of the niacin need. |
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How much tryptophan is required to produce 1 mg of niacin?
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60 mg of tryptophan
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Which nutrients are required for niacin synthesis?
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Iron, riboflavin, and B6
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What is the main form of niacin in animal foods, supplements, and circulating blood?
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Nicotinamide
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What is the max amount of niacin dosage for 100% absorption rate?
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3-4 g
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What is the form of niacin bound to a carbohydrate called?
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Niacytin
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What is the name of a niacin bound to a peptide?
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Niacinogens
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How does the covalent bond of niacin to carbs or peptides in plant food effect its bioavailability?
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It reduces it (especially in corn)
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What can increase bioavilability of niacin?
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Treatment with lime or HCL
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What is the NE in the RDA mean?
What is the RDA of niacin for women/men? |
NE= 1 mg of niacin or 60 mg of tryptophan
Women: 14 NE/ day Men: 16 NE/ day |
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What may impair niacin absorption?
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Chronic diarrhea or irritable bowel syndrome
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How do you assess niacin?
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By measuring urinary excretion of niacin metabolite (N'methyl nicotinamide)
Desirable: Greater then 1 mg/ day |
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What are the co enzymes of niacin?
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NAD and NADPH
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What is the fucntion of NAD?
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Electron acceptor (or carrier)
-Used in oxidation reactions |
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What is the function of NADPH?
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Hydrogen donor
-Used in reduction reactions -Used in biosynthesis pathways |
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How is NAPH involved in Vit C reduction?
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-It reduces DHA to form active AA
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What is the deficiency from Vit C called? Explain
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Pellegra
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What are the three D's of pellegra?
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Dermatitis, diarrhea, dementia, and (death)
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What are some common causes of niacin deficiency?
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Corn diet, Alcoholism, pharmaceutical drugs used for cancer, and tuberculosis.
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What is Hartnup Disease?
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A gene mutation which effects a sodium-depend neutral amino acid transport protein in the instestine and kidneys
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What is the UL of niacin? what does it cause?
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35 mg, vasodialation, liver injury, heart burn, high blood glucose
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What are some benefits of megadosing? (6g)
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treats hypercholesterolemia, increased HDL synthesis
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Will all individuals respond the same to niacin deficiency?
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NO- due to nutrigenomics.
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