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39 Cards in this Set
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What is the function of vitamin B1 - thiamin?
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Part of the co-enzyme TPP (thiamin pyrophosphate) which works with PDH (pyruvate dehydrogenase; enzyme between pyruvate and acetyl-coA -- when pyruvate is active, 38 ATP produced; no PDH only 4 ATP)
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What causes vitamin B1 - thiamin deficiency?
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A reduction of food intake
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What are the symptoms of vitamin B1 (thiamin) deficiency?
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Beriberi - chronic thiamin deficiency, chronic weakness, weight loss
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What's the difference between brown and white rice?
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Brown vs white rice (bran layer of brown rice is thiamin rich - removal makes white rice)
Therefore brown rice is healthier but white rice is faster and easier to cook |
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What vitamin B2?
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Riboflavin
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What is the function of vitamin B2 riboflavin?
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Co-enzymes FMA, FAD - picks up electrons and proteins, contributes to electron transport chain
Electron acceptor/transporter (keeps energy pathway going) |
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What are the associated symptoms of vitamin B2 riboflavin deficiency?
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Ariboflavinosis (inflammation of membranes such as mouth, eyes, GI system, skin)
Accompanies many other micronutrient deficiencies |
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What is vitamin B3 and it's other forms?
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Niacin (nicotinic acid and nicotinamide)
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What is the function of vitamin B3 niacin?
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Coenzymes/precursor for NAD and NADP
Can be synthesized from tryptophan (EAA) Antioxidant Role in lipid synthesis |
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What occurs with a deficiency of vitamin B3 niacin?
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Pellagra - 4 D's
diarrhea, dermatitis, dementia, death |
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What are the associated symptoms of vitamin B3 niacin toxicity?
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Niacin flush (supplement form 3 to 4 times RDA) in nicotinic acid form. Blood vessel dilation, painful tingling sensation.
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What are the benefits and pharmacological doses of taking vitamin B3 niacin?
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High doses can treat LDL cholesterol but must be monitored for side effects
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What is the function of biotin?
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Coenzyme that is involved in the Kreb's cycle
Part of pyruvate carboxylase (makes oxaloacetate from pyruvate) Contributes to gluconeogenesis, fatty acid synthesis |
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What causes biotin deficiency?
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Chronic consumption of raw egg whites (egg whites contain avidin, which binds to biotin)
Skin rash, hair loss, neurological symptoms |
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What is the function of pantothenic acid?
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Part of co-enzyme A; makes Acetyl CoA
Synthesis of lipids, neurotransmitters, hormones, hemoglobin |
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What are symptoms associated with pantothenic acid deficiency?
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Fatigue, neurological symptoms
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What is the function of B6?
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Functions as a co-enzyme
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What does vitamin B6 have to do with protein metabolism?
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11 non-essential AAs, without B6 all AAs become essential. Basically B6 part of enzyme (amino transferase) makes non-essential AAs
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What does vitamin B6 have to do with blood cell synthesis?
Deficiency of B6 in this dimension results in? |
Red and white blood cells
Assists with oxygen binding to hemogloblin Deficiency leads to microcytic hypochromic anemia (RBC smaller than normal and lacks Hb) |
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How does Vitamin B6 reduce the risk of myocardial infarction?
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PLP-dependent enzymes convert homocysteine to cystein (PLP = B6) > High levels of homocysteine is related to plaque formation (CVD)
Homocystinuria - inherited disease, lack of enzyme metabolizing cysteine |
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What food sources can one get vitamin B6 from?
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B6 happens to be quite abundant in food sources
Fortified ready to eat cereals Meat, fish and poultry Bananas, watermelon, potatoes |
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Vitamin B6 deficiency is ...
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rare; leads to anemia, nervous system symptoms ... accompanies other nutritional deficiencies
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Vitamin B6 toxicity can lead to ...
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Protein modification where neurons can be affected leading to permanent nerve damage
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What are the components of folate?
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3 parts (glutamate, PABA, and pteridine)
3-11 glutamate molecules; only AA metabolized by brain neurons |
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How does folate exist in the small intestine?
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1 glutamate remains and becomes folic acid (most stable form used in supplements and fortification)
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What are the functions of folate?
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Amino acid metabolism
DNA synthesis Cell division Most critical in embryo formation |
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What is the purpose of fortifying foods?
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Folate deficiency is linked to birth defect (conception and early development)
Cooking easily destroys food sources of folate (steaming, stir-frying, microwaving) Foods are fortified because folate is not as abundant in foods |
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What is associated with folate deficiency (the most prevalent deficiency)?
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Heart disease (Elevated homocysteine levels)
Megaloblastic anemia - due to impaired DNA synthesis in developing RBC DNA synthesis impaired - RBC, WBC, and GI cells |
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What are the implications of folate deficiency in neonatals and newborns?
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Folate is important in embryonic growth, fetal growth, newborn growth for DNA synthesis
Neural tube defects (incomplete closure of spinal canal; anencephaly where part or all of brain missing) |
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For how long can the body store folate?
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1-4 months
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What is B12?
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A water soluble vitamin (cobalamin, cobalt-containing compounds)
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What are the functions of B12?
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Plays a key role in folate metabolism
Helps to maintain myelin sheath |
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Where is B12 absorbed?
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In the ileum, binds to a protein transporter
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What happens in B12 toxicity?
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None established
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Vitamin B12 deficiency can be caused by ...
Those at most risk are ... |
Impaired absorptions which may require monthly injections (B12 stored in liver)
Vegetarians are at risk; supplements or fortified cereals Vegan mothers nursing; recommended to take supplements |
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How is Vitamin C an anti-oxidant?
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Stabilizes superoxide to peroxide
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What are 4 other function so Vitamin C?
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Collagen synthesis: needed for tissue injury, inflammatory response, increases rate of collagen synthesis
Enhances non-heme iron absorption (plants) Synthesis of carnitine; beta-oxidation Supports immune function |
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Toxicity of Vitamin C is due to ..... with the associated symptoms including ....
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Megadose (10x RDA)
Abdominal cramps, nausea, nosebleeds Existing kidney disease, kidney stone development |
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What is hemochromatosis and what does it have to do with Vitamin C?
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Metabolic disorder, excess iron deposits in body due to action of vitamin C enhancing iron absorption
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