Vitamin C 1 citrus 2 broccoli 3 brussell sprouts 4 green peppers 5 cantaloupe 6 strawberries 7 papaya Sources Structures Forms Vitamin E Plants 1 oils from plants canola olive sunflower safflower cottonseed 2 mayonnaise margarine peanut butter 3 whole grain cereals 4 legumes Animal Products 1 fatty tissues inferior to plant productus Vitamin K 1 leafy greens kale swiss chard turnip watercress collards spinach mustard greens 2 broccoli 3 cabbage 4 oils soybean rapeseed olive oil 5 lower GI not enough to meet needs Vitamin A Retinoids foods of animal origin 1 liver 2 cheese 3 fish 4 liver oils of fish Carotenoids yellow orange and red fruits vegetables 1 carrots 2 tomatoes 3 squash 4 cantaloupe 5 broccoli 6 spinach 7 beets Closely resembles glucose Synthesized from glucose or galactose in most animals plants Human one of few animals unable to synthesize lack enzyme gulonolactone oxidase Free ascorbic acid main form in supplements Dehydroascorbic acid Phenolic functional group located on chromanol ring attached to phytyl tail Tocopherol saturated side chain Tocotrienols unsaturated side chain a tocopherol most biologically active synthetic forms of vitamin E more stable all forms are used when est a tolerable upper limit Phylloquinone green plants Menaquinones synthesized by bacteria in gut Menadione synthetic form converted to menaquinone in liver Supplements 1 all trans retinyl acetate 2 all trans retinyl palmitate Retinoids o Retinol o Retinal o Retinoic acid o Retinyl esters Carotenoids Pro A o Over 600 60 converted to retinol o B carotene o a carotene o B cryptoxanthin Carotenoids o Lutein o Lycopene red o Zeaxanthin orange o Canthaxanthin red orange Vitamin C Vitamin E Digestion Absorption GLUT transporter or passive diffusion Factors influencing absorption Digestion Bile salts emulsify Micelle formation Passive diffusion with fat o High intakes 12g 16 o Low intakes 20mg 98 o Large amounts of iron may absorption Enterocyte Incorporated into chylomicron carries exogenous TG Digestion Absorption Vitamin K Digestion Absorption Jejunum o bile salts Colon o passive diffusion Enterocyte o formation of chylomicrons for transport Factors influencing o Vit A and E may absorption Transport Chylomicron remnants deliver vit K to liver Incorperated into o VLDL LDL and HDLs Transport Chylomicron remnants CR deliver vit E to liver Transferred among lipoproteins o HDL LDL o VLDL utilizes a tocopherol transfer protein genetic mutation of a TTP causes vit E deficiency can t get it to cells Tissues Delivery lipase Storage o LDL receptor mediated endocytosis o VLDL lipoprotein o Main storage tissue adipose o Smaller amounts in liver heart lung muscle Vitamin A Digestion Absorption Preformed Vit A o 70 90 bioavailable o micelle formation Carotenoids o 5 60 o small amounts of B carotene passes thru membrane unchanged o micelle formation Factors influencing Vit E large doses may inhibit conversion of B carotene to retinol Metabolism CRBP cellular retinol binding protein LRAT lecitin retinol acyl transferase esterifies fatty acid onto CRBP bound retinol to form CRBP retinyl palmitate Transport Chylomicrons Holo RBP TTR Complex Lipoproteins carotenoids o Transports retinol from liver to o Retinol binds RBP o In plasma Holo RBP binds to tissues TTR o Holo RBP TTR complex carried as part of thyroxine Storage Vitamin C Antioxidant Reversing oxidation by donating electrons and hydrogen ions Regenerates other antioxidants Vit E Glutathion These reproduce reactive oxygen species anything that can cause oxidative damage In blood or intracellulary give radicals an electron hyd ion Pro oxidant Reduce transition metals Vit C is oxidized to semi dehydroascorbate in vitro NOT in vivo Collagen Synthesis Proline hydroxyproline Iron ferrous to ferric prolyl hydroxylase ferric ferrous vit C Carnitine Synthesis Carnitine transports FA s from cytosol to mitochondria for B oxidation Catecholamine Synthesis Norepinephrine Dopamine monooxygenase oxidizes Cu1 to Cu2 Other Microsomal metabolism o Exogenous synth of bile acids from cholesterol aldosterone cortisol syth o Xenobiotics drugs alcohol carcinogens food additives pollutants undergo rxns using monooxygenases P450 require Vit C as reducing agent Colds Cancer intake of fruits veg linked with a risk of some cancers mouth throat stomach lung colorectal Cardiovascular Disease vit C status blood total cholesterol concent vit C intakes risk of heart disease and stroke Vitamin E Membrane Integrity Patients with low vit E diet for 3 years RBC fragility Prevents oxidation of unsaturated FA s in phospholipids membranes of organelles are susceptible due to increased amounts of unsaturated FA s in membranes cell membranes exposed to greatest amounts of oxidation particularly RBC s increased amounts of PUFA s and exposed to increased concentrations of oxidation Antioxidant in cell mem Free radical termination reacts with peroxide radicals before they damage FA s in cell membranes singlet oxidation quenches accepts energy Other Decreases activity of HMG CoA reductase cholesterol syth reducing cholesterol levels decreases tumor growth Decreased cell proliferation Heart disease reduced LDL oxidation reduced platelet aggregation Cataracts functionally it should Functions Vitamin K Posttranslational carboxylation of glutamyl residues glutamic acid y carboxyglutamate allows for clotting to begin Blood Clotting Vit K forms y carboxyglutamate on proteins Factors II VII IX X o II prothrombin inactive zymogen hydrolyzed into thrombin blood coagulation cascade Ca dependent Thrombin converts fibrinogen to fibrin solid material that forms clot VII IX X other blood clotting factors Inhibitors of Blood Coagulation Proteins C S possibly Z Osteocalcin Aka bone Gla protein BGP bone remodeling facilitate binding of Ca in hydroxyapatite lattice maintain serum calcium levels Vit K dependent As retinyl esters Mainly in liver stellate cells Vitamin A Retinol Visual Cycle rods cones o Rods Rhodopsin 11 cis retinal opsin Light changes 11 cis retinal to all trans retinal activates opsin binds to G protein GTP sends visual signal to brain 11 cis retinal must be regenerated to send next visual signal to brain Night blindness delayed recovery of vision in dark after exposure to flash of light vit A status directly related Cellular Differentiation o Keratinocytes retinoic acid differentiates keratinizing cells into mucus secreting cells eyes nose Gene Expression retinoic acids bind to RAR retinoic acid
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