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The Vitamins David L. Gee, PhD Professor of Food Science and Nutrition Central Washington University FCSN 245 - Basic Nutrition
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Dietary Supplement Use (USA) z$ 4,300,000,000 for vit/min in 1995 z$ 1,400,000,000 for herbs z35-40% adults regular users yfemales > males y66% multi-vit/min y37% vitamin C y19% vitamin E yCalcium supplements
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Dietary Supplement Use: Pros zSupplements dietary deficiencies ycalcium yfolic acid zAmounts used in some studies not attainable with dietary sources yantioxidants zRelatively low cost
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Dietary Supplement Use: Cons zFalse sense of security yfolic acid and pregnancy zDoes not contain all potentially useful chemicals in foods yExample: compounds found in plants that may be health promoting (phytochemicals) zToxicity almost only due to supplement use zCosts significant ylow income yHeavy users of supplements (athletes) yCertain supplements are expensive xChondroitin sulfate – bone/cartilage: $30-50/mo xSAMe – depression: $40-50/mo
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Exam 3 – Tuesday, March 6 zProteins and Amino Acids (chap 6) yEAA, RDA, functions, athletes yGenetically modified foods (p 472-480) yVegetarian diets yProtein quality yProtein deficiency (kwashiorkor/marasmus) zEnergy and Weight Loss (chap 9) yEnergy, TEE, BMR, factors affecting BMR, activity, TEF yCalorimeters (bomb, direct, indirect) yWeight loss, obesity risks, QOL, prevalence, high risk groups yHealthy weight, assessment xCalculate BMI, know cutpoints for blood pressure, sugar, lipids yDietary approaches (Balanced, Lo-Carb, restrained CHO, non-diet yExercise yDrugs/Surgery
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Vitamin & Mineral Deficiency: A Global Progress Report UNICEF, 2004 z80 developing countries studied yAccounts for 80% of world population z1/3 rd of world population do not reach their physical and intellectual potential because of vitamin/mineral deficiency
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Vitamin & Mineral Deficiency: A Global Progress Report UNICEF, 2004 zVitamin A deficiency z40% of children <5yrs with mild to severe deficiency xCompromised immune deficiency xblindness xstunted growth yContributes to 1 million deaths of young children/yr yA Solution: supplementation with beta- carotene, 2x/yr, fortification of foods
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Vitamin & Mineral Deficiency: A Global Progress Report UNICEF, 2004 zIodine deficiency zGoiter: enlarged thyroid gland, lethargy yCretinism: severe mental and physical retardation in infants of deficient mothers xReduces IQ by 10-15 points x80% of developing countries have goiter rates of > 10% yA Solution: iodized salt (use declined from 75% to 65% in last decade!)
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Myxedematous endemic cretinism in the Democratic Republic of Congo : Four inhabitants aged 15-20 years : a normal male and three females with severe longstanding hypothyroidism with dwarfism, retarded sexual development, puffy features, dry skin and hair and severe mental retardation. Woman with iodine deficiency resulting In a goiter.
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Vitamin & Mineral Deficiency: A Global Progress Report UNICEF, 2004 zIron deficiency zAnemia: fatigue, apathy in adults, poor academic performance in children (7-10pt drop in IQ) y~45% of children between 6mo-2 yrs x20 countries over 70% yA solution xSupplementation (bad taste, constipation) xFortification Salt with iodine and iron Vitamin/mineral mixes added to foods Fortified foods
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The Discovery of Vitamins zThe Germ Theory of Disease yScurvy: Disease of sailors yBeri-Beri: Disease of poor Asians
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The Discovery of Vitamins zThe Germ Theory of Disease yRickets: Disease of poor Northern European children yPellagra: Disease of poor corn eating cultures
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The Discovery of Vitamins zThe Vitamin Theory of Disease yScurvy: Disease of sailors xVitamin C deficiency yBeri-Beri: Disease of poor Asians xThiamin deficiency yRickets: Disease of poor Northern European children xVitamin D deficiency yPellagra: Disease of poor corn eating cultures xNiacin deficiency
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Vitamins: Definition zOrganic compound found in foods zRequired in small amounts zRequired in the diet (dietary essential) zProven to be required for health, growth, and reproduction ydeficiency syndrome identified
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Vitamin Nomenclature zFat soluble “A” & Water soluble “B” z“Vital amines” y vitamines = vitamins zVitamin B “complex” ycollection of water soluble vitamins that function as enzyme co-factors zVitamin C zVitamins D and E zMistaken Vitamins
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Fat and Water Soluble Vitamins zFat Soluble Vitamins (A, D, E, K) zSoluble in lipids and solvents zExcess stored and not excreted zExcess may be toxic zDeficiency slow to develop
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Fat and Water Soluble Vitamins zWater Soluble Vitamins zB vitamins, C zSoluble in water zexcess excreted in urine, little stored zgenerally less toxic zdeficiency develops quickly
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General Functions of Vitamins zHormones yVitamin D xcalcium homeostasis yVitamin A xcell division and development
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General Functions of Vitamins zNon-specific chemical reactions zVitamin E yantioxidant zVitamin C ychemical reducing agent
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General Functions of Vitamins zCoenzymes or Cofactors ychemicals that assist enzymes to function as catalysts xB vitamins xVitamin C, A, K
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Vitamin A: types and sources zRetinoids yretinol, retinal, retinoic acid yanimal foods, milk fortification zCarotenoids ybeta-carotene yplants yvitamin A precurser
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Vitamin A: functions zVisual pigment: rhodopsin y“night blindness” zMaintenance of epithelial cells yregulation of keratin protein synthesis yXeropthlamia yintestinal malabsorption zBone and Immune System Development
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Vitamin A: Deficiency zCommon in developing countries y3 million children with severe deficiency xblindness, poor growth and appetite y275 million children with mild deficiency ximpaired immunity
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Vitamin A: Toxicity z10 times RDA chronically z100 times RDA acute dose zhair loss, joint pain, birth defects zcarotenoids are non-toxic ztoxicity due to vitamin supplement overdose
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Vitamin D: Types and Sources zDietary sources: animal foods, fortified milk zHuman Synthesis of Vitamin D zSkin: cholesterol + sunlight y“Sunshine Vitamin” – UV-B rays yVitamin D 3 y 5-10 minutes, arms and legs, mid-day sun zLiver & Kidney for activation y1,25-di-OH-D 3
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Final Exam – Winter 2007 zTuesday, March 15, noon z25% vitamins and minerals yLecture materials xGeneral info on vitamins/minerals xDeveloping world vitamin/mineral deficiencies yRequired reading xChapter 7 (vitamin C ; vitamin A/carotenoids ) xChapter 8 (nutrients involved in bone health) xChapter (iron ; folate & B-12 )
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Final Exam – Winter 2006 z75% comprehensive y“questions that you should know the answers to one or two years from now.” xStudy class notes xReview old exams
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Vitamin D: Functions zHelps regulate blood calcium levels yWhen blood calcium levels are low, vitamin D (and other hormones): zIncreases dietary calcium absorption zDecreases urinary calcium excretion zIncreases bone calcium mobilization
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Vitamin D: Deficiency zRickets ybone deformities in children zOsteomalacia yweak bones due to low calcium content yVitamin D deficiency yCalcium deficiency ymultiple pregnancies
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Vitamin D: Toxicity z5 times the RDA chronically ycalcification of soft tissue ytoxicity due to excessive vitamin supplementation
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Calcium zFunctions zBone Structure (99%) zRegulator of Metabolism (1%) ynerve impulse transmission ymuscle contraction yblood clotting yetc.
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Calcium zRegulation of Blood Calcium y10 mg/dl of blood zhypocalcemia & hypercalcemia yabnormal muscle cramping ynerve irritation zControlled by: yvitamin D, parathyroid hormone, calcitonin
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Calcium RDA z1998 RDA’s (AI) y1300 mg/d : children & teens y1000 mg/d : adults y1200 mg/d : older Americans zUsual intakes are low
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Osteoporosis zBrittle, weak bones due to loss of total bone mass (minerals and protein) zPrevalence y11% of > 65 yrs y22% of > 65 yrs in 20 yrs y24 million fractures/yr y200,000 hip fractures, 1/6 fatal
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3D Visualization of data obtained by x-ray microtomography of the bone structure of the vertebrae of a 50 year old (left) and a 70 year old (right)
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This graph shows rates in the USA in 1984-87, adapted from Jacobsen, SJ in American J Public Health 80:872, 1990.
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An illustration of the consequence of osteoporosis on the spinal column.
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Elderly woman with dowagers hump, a marked abnormal curving of the spine caused by osteoporosis
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Other osteoporosis fact: National Osteoporosis Foundation - 2003 z10 million with osteoporosis y18 million with low bone density z1 in 2 women will develop osteoporosis sometime in their life y(1 in 8 men)
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Osteoporosis zRisk Factors zGenetics yFamily History yEthnicity yCaucasian > Asian > Blacks
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Osteoporosis zRisk Factors zGender yassociated with declines in estrogen production ypost-menopause yanorexia, female athletes
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Undertreatment of Osteoporosis in Men with Hip Fracture. Arch. Int. Med. (Oct. 2002) z10 million Americans with osteoporosis y2 million are men zOf 110 men hospitalized with hip fracture y4.5% received treatment for osteoporosis y1 year mortality was 32% yAverage age 80 yrs zOf 253 women hospitalized with hip fracture y27% received treatment for osteoporosis y1 year mortality was 17% yAverage age 81 yrs
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Osteoporosis zRisk Factors zChronic Calcium Deficiency zLack of Exercise
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Prevention of Osteoporosis zExercise zDietary Calcium z“Rule of 300” y300 mg/d from plant sources y300 mg/d from each serving of dairy
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Prevention of Osteoporosis zOther factors that may increase calcium loss yhigh caffeine intake yhigh protein intake yhigh alcohol intake ycigarette smoking
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Prevention of Osteoporosis zCalcium Supplements zCalcium carbonate yleast expensive yTums ypoor absorption zCalcium citrate/malate (CCM) yexpensive, well absorbed
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Prevention of Osteoporosis zAdequate amounts of vitamin D yavoid excesses zHormonal replacement in high risk women http://www.mhhe.com/biosci/ap/mediacentral/nutrition_animations/osteoporosis_final.swf
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Folic Acid zDRI (RDA): 1998 y400 ug/d (180-200 old RDA) y600 ug/d pregnancy (400) zTypical folate intake: 200 ug/d zDietary Sources yfoliage: fruits & vegetables
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Folic Acid zFunctions z“single carbon metabolism” yDNA synthesis (cell division) yother reactions
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Folic Acid zDeficiency zMegaloblastic Anemia ylarge abnormal red blood cells zElevated blood homocysteine yCHD risk factor
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Folic Acid zDeficiency zNeural Tube Defects yspina bifida - lower body paralysis yrequired early in pregnancy zGrain fortification (1998) ywill add 100-200 ug/d to diet
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Vitamin B-12 zCobalamine zcontains cobalt zDRI (1998) : 2.4 ug/d (old 2 ug/d) zDietary sources: yanimal foods yfortified cereals
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Vitamin B-12 zFunctions z“single carbon isomerization” ysynthesis of DNA (folate interaction) ynerve fiber sheath synthesis
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Vitamin B-12 zDeficiency zPernicious Anemia ymegaloblastic anemia ynerve injury yperipheral weakness and numbness yprogressive degeneration to death yconcern among the elderly
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Vitamin B-12 zDigestion and Absorption zRequires functioning stomach y“intrinsic factor protein” yacid production
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B-12 and Folic Acid zExcessive folic acid can mask nerve degeneration of pernicious anemia zFDA regulates dosage of folate supplements zFDA limited amount of folate fortification in grains
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Nutritional Antioxidants zOxidative Tissue Injury zOxygen free radicals yunpaired electrons ysuperoxide O 2 -. yhydroxy free radical OH. yhydrogen peroxide
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Oxidative Tissue Injury zCauses chain reactive damage to: zCell membranes (hi PUFA) zProteins zDNA
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Oxidative Tissue Injury zAssociated with: zCoronary Heart Disease yoxidized LDL-cholesterol zCarcinogenesis zChemical Toxicity zAuto-immune dieseases zAging
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Sources of Oxygen Free Radicals zNormal energy metabolism znutrient + O 2 --> CO 2 + H 2 O + energy zElectron transport system yO 2 --> H 2 O + energy zbut: O 2 --> O 2 -. --> H 2 O + energy
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Sources of Oxygen Free Radicals zD-amino acid metabolism yD-AA --> C-skeleton + ammonia + H 2 O 2 zMetabolism of foreign chemicals ydrugs, pesticides, toxins, etc... zOzone, nitrogen oxides, UV light, smoke, radiation, etc...
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Cellular Antioxidants zAntioxidant Enzymes zCatalase (iron) yremoves hydrogen peroxides zSuperoxide Dismutase (Cu, Zn) yremoves superoxide radicals
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Cellular Antioxidants zAntioxidant Enzymes zGlutathione Peroxidase (Se) yremoves peroxides zMineral supplements are ineffective and may be toxic
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Cellular Antioxidants zNutritional Antioxidants zVitamin E zCarotenoids and other plant phytochemicals zVitamin C
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Vitamin E zTocopherols zDietary sources: ywidespread, highest in plant oils zDeficiency: yrare in adults ypremature infants: hemolytic anemia
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Vitamin E zFunction: yfree radical scavenger in membranes zRDA: 8-10 mg/d z“Research dosages”: 400-800 mg/d zToxicity: rare, may be non-toxic below 1000 mg/d
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Plant Phytochemicals zBeta-carotene & carotenoids zPlant polyphenols ygarlic ygreen tea ygrape skins ycruciferous vegetables zAntioxidants with “specific niches”
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Vitamin C zAscorbic Acid zFood Sources yfruits yvegetables zDeficiency: Scurvy ypoor wound healing yimpaired immune system
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Vitamin C Functions zAntioxidant ywater soluble free radical scavenger zCollagen synthesis yconnective tissue protein zSynthesis of neurotransmitters, thyroxine, etc. zAids in absorption of dietary iron
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Vitamin C zRDA : 60 mg/d zRDA (smokers): 100 mg/d ztypical intake 100 mg/d z“Effective research dosages” : 100-500 mg/d
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Vitamin C z“Toxicity” > 1000 mg/d zdiarrhea zkidney stones zpromotes “iron overload” toxicity zInterfers with important lab tests yblood in stools (colon cancer) yurinary and blood glucose (diabetes)
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Iron zFunctions: zHemoglobin zMyoglobin zIron enzymes ycatalase yelectron transport system
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Iron Deficiency zIron deficiency anemia yfewer, smaller, paler red blood cells yfatigue z5-10% of US premenopausal women zup to 40% of population in developing countries
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Iron Deficiency Causes zBlood loss ymenstrual blood loss yparasites and bleeding ulcerations zInadequate dietary intake zRDA men = 10 mg/d zRDA women = 15 mg/d zUS usual intake 6 mg/1000 Cal
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Dietary Sources of Iron zHeme Iron ymeats (Hb & Mb) y20-30% absorbed zNon-heme Iron yplants yinorganic iron y1-10% absorbed yvitamin C increases absorption yiron cookware
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Iron Overload Toxicity zChildren (accidental poisoning) zMen and post-menopausal women zGenetic “defect” yimproved iron absorption zExcess iron is a pro-oxidant. yoxidized LDL-C ytissue injury
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Iron Overload Toxicity zMay occur in 10% of men zTreatment yavoid iron containing supplements yavoid excess vitamin C supplements ybleeding or blood donation
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