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29 Cards in this Set
- Front
- Back
Iron Sources
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Foods:
–Heme iron •Meats,seafoods –Non-heme iron •enrichedbakery products (iron phosphate) |
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Iron Needs
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–RDA:18 mg/day adult women, 8 mg/day adult men •Aftermenopause drops to 8 mg/day –AverageNorth American intake: 12-17 mg/day |
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Iron Absorption and Storage
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–Heme vs Nonheme •heme ironis more readily absorbed it does not have to be reduced –Stored •Ferritin |
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Iron Transportation and Excretion
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–Transferrin –Lysosomes—cellsthat digest proteins –Hemosiderin–iron-binding protein in the liver–90%recycled •Iflost –in bile of feces |
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Factors affecting iron absorption
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•Factors Affecting Iron Absorption –Body’s iron needs and stores •Adequate ~15% (14% to 18%) •Low ~35% to 40% •High ~5% –Form of iron in foods eaten •Heme vs nonheme –Dietary composition •Nonheme hindered by dietary factors –Oxalic acid and phytic acids –Polyphenols (tannins) –Increased by vit C –Gastric contents acidity •Promotes conversion of ferric (Fe3+) to ferrous (Fe2+) |
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Functions of Iron
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•Redox reactions –Ferrous (Fe2+) to ferric (Fe3+) Can be damaging produce free radicles •Part of Hemoglobin and Myoglobin –Transport and metabolism of oxygen •Iron-containing enzymes –Energy metabolism, mitochondrial cytochromes, –Drug metabolism in liver by iron-containing enzymes •Enzyme co-factor –Synthesis of neurotransmitters –Production of immune system components |
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Iron deficiency, Overload and Toxicity
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•Deficiency –Mostwidespread mineral deficiency worldwide –Irondeficiency anemia –Atrisk: premature infants, young children, females of childbearing age,vegetarians •Overloadand toxicity –UL:45 mg/day –Accidentaloverdose in children –Hemochromatosis •Theferritin and block that protects the body from excess iron absorption isineffective. |
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Zinc
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•Foods –Protein-richmeat and seafood’ also nuts, beans, and whole grains •Effectof phytic acidin whole grains •Needs –RDA:11mg/d adult men, 8 mg/d adult women –DV:15 mg •Absorption—SIby simple diffusion & active transport •Metallothionein—similarto ferritin •Transportation-protein carrier (like albumin) •Storage—none •Excretion---readilyexcreted in feces - Decreasingrisk of toxicity |
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Zinc Functions
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–Asmany as 300 different enzymes require zinc •DNAand RNA synthesis, hemesynthesis, bone formation, taste acuity, immune function, reproduction, growth,etc. |
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Zinc Deficiency and Toxicity
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•Deficiency –Overtdeficiency common when poverty limits food choices –NorthAmerica: mild or marginal deficiencies •malabsorptivediseases, dialysis, limiting animal foods •Toxicity–UL:40 mg/day |
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Copper
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•Foods –Liver,shellfish, nuts, seeds, lentils, soy and dark chocolate •Needs –RDA:900 micrograms/daily –DV: 2mg –Averageintake 1,000 to 1,600 micrograms daily •Absorption—SIby simple diffusion and active transport •Transportation—bloodby albumin •Storage—littleto none, excess binds to Metallothionein •Excretion—throughbile in feces |
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Functions of Copper
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•Functions –Componentof enzymes •Cu1+ and Cu2+ –Superoxidedismutase enzymes (SOD) •Eliminatesuperoxide free radicals which prevent oxidative damage –Electrontransport chain •CytochromeC oxidate |
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Copper Toxicity
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–Abdominalpain, nausea, vomiting , diarrhea –Wilson’sdisease –UL:10mg/day |
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Manganese
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•Foods –Whole-graincereals, nuts, legumes, leafy greens, and tea •Needs –AI:2.3 mg/d adult men, 1.8 mg/d adult women –DV: 2mg/daily •Absorption—SIby simple diffusion and active transport •Transportation—boundto alpha-2-macroglobulin to liver –Transferrin,alpha-2-macroglobulin, or albumin to tissues •Storage—none •Excretion--bile |
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Manganese Functions
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–Sharesfunctional similarities with Zinc and Copper - Carbohydratemetabolism, gluconeogenesis,collagen formation, antioxidant system, etc. |
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Manganese Deficiency and Toxicity
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•Deficiency –Rareand few reported •Nauseaand vomiting, poor growth, skeletal abnormalities, and impaired carb and lipidmetabolism •Toxicity–UL:11 mg/day Toxicites have been reported in children receviing longterm PTN (parental nutrition)Cause neurological impairmentsimilar to Parkinson's UL set to preventnerve damage |
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Iodine
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•Foods –Saltwaterseafood, seaweed, iodized salt, and dairy products –Goitrogensdecrease bioavailability of iodine and inhibit use of iodine by thyroid gland •Concernin less developed parts of world –Highveggie intake—but cooking destroys goitrogens •Needs –RDAand DV: 150 micrograms/d –Averageintake 190-300 micrograms •Absorption---inform of iodide--SI•Transportation—tothyroid •Storage—trappedin thyroid to support thyroid hormone synthesis •Excretion—excessin urine Dairy not a good source—a byproduct from thedairy feed Plant based foods if high iodine insoil. |
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Functions of Iodine
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–Essentialcomponent •thryoxine (T4)–majority in body •triodothyronine(T3)—active form –Enzymeneeded for this conversion to T3 is selenium |
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Deficiency and Toxicity of Iodine
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–IodineDeficiency Disorders (IDD) •Endemicgoiter---thyroid hormone enlarges to “trap” more iodine •Endemiccretenism—restrictionof brain development and growth –Infetus •Toxicity–UL:100 micrograms/d–Enlargedthyroid gland |
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Selenium
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•Foods –Dependenton soil content –Seafood,meats, cereal, and grains •Rice •Needs –RDA:55 micrograms adults –DV:70 micrograms •Absorption—boundto AA methionine and cysteine—SI from 50 to 100% •Transportation—transportprotein •Storage—poolin tissues |
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Functions of Selenium
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•Functions –Antioxidantdefense network •Glutathioneperoxidase –Thyroidmetabolism (T4 to T3), immune function, etc. |
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Deficiency and Toxicity of Selenium
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•Deficiency –Notestablished –Associatedwith Keshandisease •Insufficietncardiac function –Chinawhere soil is devoid of selenium •Toxicity –UL:400 micrograms/d –Canbe seen in 1 to 3 mg/d taken over several months –Nausea,diarrhea, fatigue, hair loss, changes in nails |
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Chromium
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•Foods –Nutrientdatabases inadequate –Processedmeats, liver, eggs, whole grain products, broccoli, dried beans, nuts, darkchocolate •Needs –AI:35 micrograms men up to age 50, then 30 micrograms; 25 micrograms women up toage 50, then 20 micrograms –DV:120 micrograms •Absorption—verylittle from diet –Increasewhen low and consumed with Vit C •Transportation—ferritin •Storage—bone,liver, kidneys, and spleen •Excretion—fecesand urine |
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Functions and Deficiency of Chromium
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•Functions –Nofully know –Mayenhance insulin function and promote glucose uptake •Deficiencyand Toxicity –Notwell established –No UL |
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Fluoride
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•Foods –Fluoridatedwater, tea, seafood, and seaweed •Needs –AI:3 mg/d adult women, 4 mg/d adult men •Absorption—SIby passive diffusion •Transportationin bloodstream •Storage—teethand bone •Excretion—calcifiedtissue deposits and urine |
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Fluoride Functions
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•Functions –Depositionof Ca andP in teeth and bones •Promotesbone and dental health –Hydroxyfluorapatitecrystals greater resistance than Hydroxyapatite crystals |
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Fluoride Deficiency and Toxicity
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•Deficiency –Associatedwith an increase in dental caries •Toxicity –UL:0.1 mg/kg body weight/d up to 8 years old, 10 mg/d over 8 years old –Mottling(fluorosis) |
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Molybdenum
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•Molybdenum –Dietarysources: plant-based foods; soil dependent
–RDA:45 micrograms/d; DV: 75 micrograms/d –Functions:cofactor in enzymatic reactions –UL:2000 micrograms/d•Preventgoutlikesymptoms |
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Ultra Trace Minerals
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•Notclearlydefined ultra trace minerals –Mostlikely cofactors for specific enzymes or compounds –Nickel,Vanadium, Boron,Silicon, and Arsenic •UL’s due to toxicity concerns associated with increased exposure |