ZINC Males ages 19 30 11mg d Females ages 19 30 8mg d RDA Sources Foods One oyster has 12 8mg Seafood Meats Eggs and dairy products Whole grains Vegetables Supplements Endogenous sources already in body Carboxypeptidase Topical applications Absorbed through skin Absorbed better if you have burn cut Diaper rash cream Forms Digestion 2 Zn Universally found in divalent state Eaten attached to amino acids Stomach and small intestine Proteases and nucleases Work to split up proteins and metals HCL Denatures proteins and exposes all peptide bonds Antacids and proton pump in inhibitors increase pH and decrease absorption Absorption Proximal small intestine upper jejunum duodenum Carrier mediated process ZIP4 main protein that allows Zn into cell Zrt and Irt like protein De ciency of ZIP4 acrodermatitis enteropathica DMT moves anything in 2 form Low intakes vs high intakes High levels paracellular diffusion Chelators or ligands can inhibit or enhance absorption Enhancers of Zinc absorption Ligands Citric acid Amino acids Tri peptides Glycine glutathione cysteine glutamate Pancreatic secretions Has some unknown thing in it that helps zinc absorption Zinc status homeostatically regulated Low zinc status increase transcription of ZIP4 Inhibitors of Zinc absorption Form complexes Phytates Phytic acid inositol hexaphosphate Found in cereals and grains Zinc phytate complex Oxalates spinach chard berries chocolate tea Polyphenols tea bers Processes that reduce bioavailablity Heating Maillard reactions Other nutrients Divalent cations Interfere with transporter Entereocyte Used within cell Stored Metallothionein Binds both zinc and copper As Zn increases metallothionein concentrations increases Transported inside cell ZIP4 Transported within cell ZnT 2 ZnT 3 ZnT 4 Transported out of the cell ZnT 1 Transport to tissues majority taken to liver Mainly bound to albumin Tissues Albumin Transferrin Uptake Storages Amino acid use Enzyme synthesis Metallothionein Thionein Protein and storage for metals When metals are bound metallothionein Has cysteine residues that bind metals Cu Cd Hg Found in most tissues MT 1 through MT 4 Liver pancreas kidney intestine RBC Involved in 3 main Catalytic Structural Regulatory Catalytic functions over 200 enzymes req Zn Carbonic anhydrase acid base balance within blood Erythrocytes Kidney Alkaline phosphatase Found in bones and liver Has 4 zinc ions Alcohol dehydrogenase Alcohols to aldehydes NADH niacin Carboxypeptidase Zinc bound to this exopeptidase Protein digestion Superoxide dismutase antioxidant Getting rid of free radicals Regulation Tissue growth Protein synthesis Nucleic acids Bone formation Cell mediated immunity Structural Zinc ngers Zinc is needed for immune response to happen Describing the conformation change when zinc binds to DNA Deals with DNA regulation expression or suppression Cell membrane and structure Zinc membrane stabilizer Zinc also found in tubuline structural support Zn de ciency decreased insulin response impaired glucose tolerance Zn de ciency syx of anorexia and anhedonia depression Other Carbohydrate metabolism BMR Zn de ciency decreased BMR Taste acuity appetite Transport proteins Albumin and transferring Neurotransmitter receptors Changes shape of neurotransmitter Nutrient Interactions Vitamin A Aminolevulinic acid dehydratase heme synthesis Aminolevulinic synthase B6 dependent Aminolevulinic dehydratase Zn dependent Lead poisoning when lead replaces zinc on dehydratase enzyme causing a build up of ALA Copper Calcium Cadmium Lead RetinolRetinal Zinc de ciency decreased mobilization of retinol from liver Higher af nity than Zn for MT Cu will push Zn off MT results in Zn de ciency If calcium status is low Zn supplements can inhibit Ca absorption Competes with binding sites esp Zn ngers ALA dehydratase Light can interact with this Know that copper zinc and MT metallothionine have strong interaction GI tract lose majority through here Metalloproteins GI cells sloughed off every couple days Filters most reabsorbed so very little excretion Sweat hair little amounts lost Excretion Kidney Skin Assessment Serum plasma Urinary Zn poor De ciency Symptoms Plasma zinc most commonly used less than 70mg dL suggests de ciency Plasma metallothionine not as reliable Growth retardation Skeletal abnormalities bone formation Poor wound healing Dermatitis Alopecia lost of taste Hypogeusia Night blindness Vit A Delayed sexual maturation sperm depend on Zn Impaired immune function Decreased taste acuity depression anorexia Acrodermatitis Enteropathica Rare inherited disease where doesn t doesn t produce enzyme to transport Zn across enterocyte Genetic de ciency of ZIP4 Symptoms Appear within days or weeks in infants Patches of redness around body openings elbows hands and feet Patches develop into blisters and lesions Impaired wound healing hair loss Zinc supplementation 1mg kg of body weight Would get in somehow without ZIP4 DMT pericellular diffusion Treatment At risk Population those with burns or chronic infection growth spurts etc Dietary De ciency Protein energy malnutrition Vegan diets IV without Zinc Increased Requirements Burn patients Growth spurts Pregnancy and lactation Chronic infection Malabsorption Celiac Chron s Cystic brosis High phytate diets Chronic iron supplementation Cu supplementation Toxicity usually through supplementation rare UL 34 40mg d Symptoms Metallic taste Nausea Vomiting Abdominal cramps Bloody diarrhea Colds and Zn Can cause copper de ciency because of how it interacts w MT more will get trapped in storage Zinc glucconate zinc sulfate Studies show taking Zn within 24 hours of cold symptoms will reduce the severity and duration of the illness History during 1800 s linked to blood w iron 1920s anemia with animals 1960s Cu def in humans 1950s 70s menkes wilson Sources COPPER Foods Organ meats best source Shell sh Nuts Seeds Legumes Endogenous sources Forms Adult bodies 51 120mg Valence state Cuprous Cu Cupric Cu 1 2 Digestion two stable isotopes 63 65 Cu and Cu Eaten attached to amino acids Stomach and small intestine Pepsin HCL Proteolytic enzymes Absorption Stomach a little Small intestine duodenum Ligands Active carrier mediated transporters Must be in Cu cuprous reduced form hCtr1 DCT DMT 1 1 Cu not favored Fe Zn Mn favored over copper Need to be in Cu cuprous form BUT it needs to have an extra H ion Enhancers of copper absorption Amino acids Histadine Methionine and cysteine Serve as binding ligands His meth cys Organic
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