食品营养与卫生营养学第一章营养学基础

第一章营养学基础[第一节蛋白质]一．目的和要求本节是营养学第一章中重点内容；要做到全部掌握。二．重点和难点重点：蛋白质生理功能，必需氨基酸。蛋白质营养学评价，食物来源和供给量。难点：食物蛋白质营养学评价有关指标及原理。三、教学安排教学时数：2学时四、教学方法重点讲授，复习、提问、讨论相结合。应用多媒体课件。五、授课内容第一节蛋白质概念，生理功能，氨基酸和必须氨基酸，蛋白质在体内的消化、吸收和代谢食物蛋白质营养评价，蛋白质的营养不良，蛋白质来源及供給量一.蛋白质的生理功能是人体组织的构成成分是构成体内各种重要生理活性物质⑴增加免疫功能⑵维护神经系统的正常功能⑶遗传信息的控制⑷维持毛细血管的正常渗透压⑸运输功能⑹维持血液的酸碱平衡⑺参与凝血过程供给热能蛋白质的组成及一般性质基本组成元素：碳、氢、氧、氮一般性质：高分子物质，不能透过半透膜；两性分子，具有酸性和碱性，可成为缓冲体系与水形成乳胶悬浮液可发生变性和凝固二.氨基酸和必需氨基酸氨基酸和肽必需氨基酸(essentialaminoacid,EAA)概念：种类异亮氨酸、亮氨酸、赖氨酸蛋氨酸、苯丙氨酸、苏氨酸色氨酸、缬氨酸、组氨酸氨基酸膜式和限制性氨基酸氨基酸模式与限制氨基酸氨基酸模式（AminoAcid限制氨基酸（limitingaminoacid）优质蛋白质参考蛋白质(referenceprotein)蛋白质的互补作用(supplementaryaction)三、蛋白质在体内的消化、吸收和代谢收再利用的氨基酸。氮平衡(nitrogenbalance)摄入氮与排出氮的关系。表达式:NB=I-（U+F+S）I=摄入氮 U=尿氮F=粪氮 S=皮肤损失氮零平衡 摄入氮=排出氮平衡 正平衡 氮>排出负平衡 氮<排出氮四、食物蛋白质营养评价食物中蛋白质的含量：食物中蛋白质的消化率：消化率（%）=食物氮-（粪氮-粪代谢氮）/食物氮 表观消化率(%)=I-F/I*100%F=粪氮 Fk=粪代谢氮F=未被消化的食物氮FK=脱落肠粘膜细胞以及肠道细菌含氮量消化率受到蛋白质性质、膳食纤维、多酚类物和酶反应等因素的影响。食物的生物学种属愈远愈好搭配的种类愈多愈好食用时间愈近愈好蛋白质利用率生物价B：是指食物蛋白质被吸收后储留氮占吸收氮的百分比BV=氮贮留量/氮吸收量*100=I-（F-Fk）-(U-Um)/I-(F-Fk)表示蛋白质被机体利用程度蛋白质净利用率=生物学价值*蛋白质的功效比值（PER）1gPER增加体重(g)/摄入食物蛋白质(g)影响PER因素：蛋白含量 10%实验动物 断乳雄性大鼠实验时间 28氨基酸评分AAS=五、蛋白质的营养不良蛋白质缺乏原因摄入量不足（食物中蛋白质不足或胃纳不佳）排出量过多生理需要量增加而摄食量未相应改善变（怀孕）对蛋白质的吸收不良或肝脏合成蛋白质障碍偏食的饮食习惯、酒精中毒等。蛋白质缺乏的临床表现：蛋白质—热能营养不良：分为消瘦型和水肿型蛋白质营养缺乏的治疗原则：在病因治疗的基础上，全面加强营养，尽快提高患者的营养水平。六、来源及供给量畜、禽、鱼类10%～20%奶类、鲜奶1.5%～4%、奶粉25%-27%蛋类12-14%干豆类20%～24%、其中大豆含量最高50%15%～25%6%-10%供给量：0.8g/kg体重为宜我国为1.0～1.2g/kg体重供热比10％～15%[第二节脂类]一．目的和要求1．运。熟悉：脂类的分类及其生理意义，膳食脂肪营养价值评价。了解：脂肪营养不平衡，特别是过剩的危害及相应的膳食措施。二．重点和难点重点：脂肪酸的生理功能及代谢。难点：脂肪的代谢与健康的关系三、教学安排教学时数：1学时四、教学方法重点讲授，复习、提问、讨论相结合。应用多媒体课件。部分内容自学五、授课内容一、脂类的分类及功能甘油三脂,triglycerides： 食物中占95%，人体内99%脂类 磷脂, phospholipids： 5%， 1%固醇类,sterols：（一）甘油三脂甘油三脂结构：1glycerol3fattyacids功能：1)trigltceridesinthebody:体内能量贮存形式维持体温正常及保护作用内分泌作用节约蛋白质作用机体重要的构成成份其它作用：延缓胃排空，增加饱腹感促进脂溶性维生素吸收改善食物的感官性状磷脂：含有磷酸、脂肪酸、甘油和氮的化合物鞘脂类：含有磷酸、脂肪酸、胆碱和氨基醇的化合物糖脂：含有碳水化合物、脂肪酸、和氨基醇的化合物固醇类：含有环戊烷多氢菲环化合物脂蛋白：脂类与蛋白质的结合物2.(essentialfattyacid,EFA)包括:亚油酸（十八碳二烯酸、α－亚油酸。n-3n-6烯酸等，都是人体不可缺少的脂肪酸，但可由亚油酸和α－亚油酸合成。2．必需脂肪酸的功能是磷脂的重要组成成分—磷脂是细胞膜的主要结构成分，故与细胞膜的结构和功能直接相关是合成前列腺素的前体—前列腺素扩血管和收缩、神经传导等4.过多脂肪的危害性(riskofhigh-fatdiet)（二）磷脂（三）固醇(Sterols)二、脂类代谢（metabolism）三、脂类的食物来源及供给量FoodsourceandRDA（一）食物来源：动物脂肪和植物种子动物脂肪相对含饱和脂肪酸较多植物油相对含多不饱和脂肪酸较多linoleicacid(n-6):leafyvegetables,seeds,nuts,grains,vegetableoil(corn,safflower红花,soybean,cottonseed,sesame芝麻,sunflower)arachidonicacid(n-6):meats,canbemadefromlinoleicacidlinolenicacid（n-3）:fatsandoil(soybean,walnut胡桃,wheatgerm,)EPAandDHA(n-3):Humanmilk,shellfishandfish(mackerel鲐鱼,tuna金枪鱼salmon大麻哈鱼,sturgeon鲟鱼,herring鲱鱼,trout鳟鱼,sardines沙丁鱼),canbemadefromlinolenicacid.（二）供给量1.占总热能：20%---30%（饱和脂肪酸占10%以下）2.n-6占总热能不少于3%,n-6:n-3＝4:1300mg/d以下（三）脂肪代用品1.蔗糖聚酯sucrosepolyester,Olestra2.燕麦素Ostrim[第三节碳水化合物]一．目的和要求掌握碳水化合物（包括膳食纤维）生理功能、消化、吸收和供给量。熟悉碳水化合物的分类，特别是膳食纤维的分类。了解各类碳水化合物食物来源。二．重点和难点重点是碳水化合物，尤其是膳食纤维的生理功能。难点是复杂的分类及构成。三、教学安排教学时数：2学时四、教学方法重点讲授，复习、提问、讨论相结合。应用多媒体课件。五、授课内容一、分类及食物来源（一）单糖(monosaccharide)Glucose: D- andL-.Alittleinthenaturalfoods.Fructose（果糖）:主要存在于水果和蜂蜜中，人工制造的玉米糖浆中含40%-90%。碳水化合物carbohydrat类化合物，是人类能量的主要来源。galactos（半乳糖：以乳糖形式存在于天然食物中。Itisnotusuallyfoundfreeinnatureinlargequantities,butrathercombineswithglucosetoformlactose.Others:ribose()，deoxyribose()，arabinose()（二）双糖(disaccharide)Sucrose(蔗糖)：1葡萄糖＋1果糖，foundinsugarcane(甘蔗)andsugarbeets(甜菜)。Maltos（麦芽糖：葡萄糖＋葡萄糖，淀粉的水解产物。Lactos（乳糖：葡萄糖＋半乳糖，乳及乳制品中。海藻糖)：葡萄糖＋葡萄糖，真菌(fungus)（三）寡糖(oligosaccharide)3-10单糖组成。有些具有重要的生理功能。（四）多糖（polysaccharide）糖原(glycogen)动物淀粉。淀粉（starc：amylose)--老化,(amylopectin)--3.纤维（fibre）definition:Nonstarchpolysaccharidesinplantfoodsthatarenotdigestedbyhumandigestiveenzymes,butsomearedigestedbyGLtractbacteria.Fiberinfoodsiscalleddietaryfiber.Insolublefiber1)Cellulose（纤维素）2)Hemicelulose（半纤维素3)Lignin(木质素)solublefiberpectins(果胶)Gumsandmucilages(树胶和粘胶二、碳水化合物的功能提供热能。是机体重要组成物质。参与营养素的代谢，具有节约蛋白质的作用。碳水化合物具有解毒作用。抗生酮作用提供膳食纤维三、膳食纤维概念:膳食纤维又称食物纤维，是植物性食物中有的一些不能为人体消化分解的食物成分，主要包括纤维素、半纤维素、木质素、果胶、琼脂等。它们虽不能被机体吸收进入新陈代谢，但为维持身体健康所必需,而具有其独特功能。分类:分为不溶性纤维和可溶性纤维四．碳水化合物的供给(一)AI(adequateintake,适宜摄入量)Chineseadult:55%---65%0ftotalenergyUSA: 55%---60%ofthat,fiber:25g/dSugar:lessthan10%oftotalenergyintake.（二）Harmfuleffectsofexcessivecarbohydratesintake1．Causingobesity2．Heartdiseases3．DentalCaries(龋齿)4．Excessivefiberintake:Limitingtheabsorptionofnutrients.Causingabdominaldiscomfort,gasanddiarrhea.[第四节热能Section4Energy]一．目的和要求1．掌握热能单位，人体热能消耗（用）及供给量。熟悉三大热能营养素的供能比例。了解成人一日热能需要量的确定。二．重点和难点基础代谢和食物特殊动力作用对热能的消耗的计算及机理三、教学安排教学时数：1学时四、教学方法重点讲授，复习、提问、讨论相结合。应用多媒体课件。五、授课内容一、概述（introduction）(一).Unit joule(J), kilojoules(kj)calorie(cal), 1kcal＝4.184kj, 1kj＝0.239kcal（二Availableenergyinfoods1．Measuringwithabombcalorimeter2．Calculation: carbohydrate Protein 4kcal/gLipid 9kcal/gAlcohol ThebodyspendsenergyThebodyconvertstheenergyoffood:50%radiatingasheat50%asATPmolecules,butwhenATPenergyisusedtodowork,againabout50%ofATPenergyislostasheat.So75%oftotalenergyoffoodisreleasedasheat.(一)BasalMetabolismDefinitionBasicenergyexpenditure,BEE(基础代谢的热能消耗)Basalmetabolicrate,BMR(基础代谢率)Definition The rate of energyused for metabolismunder condition,usuallyexpressedaskcalper ㎡surfaceofbodyperhour(orkcalperkilogrambodyweightperhour)Calculation①㎡(body surface area)＝o.oo65×body size(cm)﹢weight(kg)－0.1603ThencalculatingwithBMR②HarrisandBenedictformulaBEE(man)＝66＋13.7×bw.(kg)＋5.0×bs.(cm)－6.8×age(y)BEE(woman)＝65.5＋9.5×bw.(kg)＋1.8×bs.(cm)－4.7×age(y)③ThemethodsuggestedbyWHOResting Metabolic Rate,RMR(静息代谢率) Measuring expenditureofbodyundertherestafter4-hourfast.ItislessthenBMR.ThefactorsaffectingBMBodysurfacearea(orleanmass>fattytissue)Gender male>femaleAge 2%ofdeclineper10yearsafterage5%ofdeclineper10yearsafterage60NutritionstateLowenergyintakedecreasesBMRabout10%-20%PregnancyincreasesBMRBodytemperatureFeverincreasesBMRHighorlowairtemperature,hormonesystemactivity,nerveandeatingtoomuchincreaseBMR(Adaptivetherogenesis用)CaffeineandtobaccoincreaseBMR(二）PhysicalActivityTheenergyneededduringphysicalactivitydependsonbodyleanmass,intensity(强度)andtimeofactivity.Theenergyisabout15%-30%oftotalenergyuseinsedentary(久坐的)people.（三）Specificdynamicaction(orThermicEffectofFood,TEF)食物特殊动力作用或食物热效应amountofextraenergyusedbybodyduringdigestion,absorption,metabolism,andstorageofenergy-yieldingnutrients.Energyexpenditurecarbohydrates 5%-6%oftotalcalorieproducedbylipids 4%-5%ofthatprotein 30%ofthatmixedfood 10%0ftotalenergyconsumed（消耗3．ThemechanismEnergystorage: ATPandfatSympatheticnervoussystemactivity4．Affectingfactorsprotein-richfoodismuchhigherthenotherslargemealsshowhighervaluesthannormalmealsTEFdecreaseswithadvancingage.Mealfrequency.三、热能需要量的确定Estimatingenergyrquirements（一）calculationcalculatingthetotalenergyexpenditurebasalmetabolismphysicalactivitiesspecificdynamicactionNutritionalsurvey(orDietary(二）measuringenergyuseby测量法）DirectcalorimetryIndirectcalorimetry四、热能推荐摄入量EnergyRecommendedNutritionIntake,RNI五、Healthandenergyintake（一）theriskofexcessiveenergy（二）限食EnergyrestrictionItisbeneficialtopreventionofmanydiseasesespeciallyforoldpeople,andprolonginglife.[第五节矿物质SECTION5 MIMERALS]一．目的和要求1．源与供给量。熟悉人体无机盐和微量元素的构成。了解磷、铜、锰、钴、钼、铬、镍等有关内容。二．重点和难点重点为钙、铁、碘、锌、硒的生理功能，缺乏病，代谢及食物来源与供给等。元素的代谢及有关机理。三、教学安排教学时数：4学时四、教学方法重点讲授，复习、提问、讨论相结合。应用多媒体课件。五、授课内容IntroductionElementsinhumanbodyTotalelementsInhumanbodyis0ver80.Essentialelementsinhumanbodyover20,ofthemabout20mineralelementsMacroelements:Ca,P,Na,K,Mg,S,CL.Microelements:Fe,Zn,Se,I,Cu,Co,Cr,F,Mn,Mo,Si,Ni,B,FunctionCompositionofhumanbodyMaintainthepHandosmoticpressure渗透压)ofbodyliquids.RegulatingtheexcitingofnerveandmuscleComponentsofprostheticgroup(),hormone,vitamin,protein,nucleicacid,andactivator（激活剂）ofenzyme.TheothersCalciumCalciuminhumanbodyCainthebody: 1.5%-2.0%ofbodyweightBone,teeth,99%: Combinedform,0.5%: Ion,0.5%：Hydroxyapatite combinedwith MiscibleCa（羟磷灰石） protein and （混溶钙池）amorphousCa citric acid Inblood,extra-（未定形钙） cellularfluid,Function

softtissue,andexchangeablePrincipalcomponentofskeletaltissueosteoblasts(成)Bone Ca(miscibleCapool)Osteoclasts(破)Renewal:Children 1-2yearAdult 10-12y(2%-4%peryear,700mg/d)After40y,Cainthebonedecreasedby~1%peryear:earlierinfemalesthaninmales;Mostrapidlyduringfirst3yearsAftermenopause;Tallerpeoplelessrapidly.Regulating neuromuscular(神经肌肉) excitability, transmissionofnerveimpulses(神经冲)andheartbeats.Influencingenzymereaction:ATPase(三磷酸腺苷酶),proteinase(蛋白酶),Lipase(脂肪酶),succinodehydrogenase(琥珀酸脱氢酶)。Others: hormone secretion, blood coagulation(凝结), balance,normalcolloid(胶体).AbsorptionandMetabolismMechanismofabsorption: inthesmallintestineTranscellular(跨细胞):saturable()(active)transferinvolvesacalcium-bidingprotein,).Paracellular()AffectingfactorsAge children:75%0fingestedCa; >40%offoodadults: 30%-60%; 20%~>70y 1/3ofadult’s; <15%~Sex: male>femalePhysiologicalsituation:pregnancyandbreast-feed>othersBodyCaconc.DietaryfactorsincreasingCaabsorption:Vit.D,lactose,aminoacids:lysine argininedecreasing~: phytate(植酸盐),oxalate(草酸盐),fibre,fattyalcohol; thyroid hormone(甲状腺素), cortisol(皮质醇andantibiotics:penicillin,neomycin,chloramphenical(氯霉)ExcretionFecalCa 194±73mg/dintheAmericanmenfromunabsorbedandendogenous内源性钙)UrineCa：dietscontaining600-800mg/drangesbetween80-250mginurine.SweatCa: 20-30mg/d;1g/dathightemp.MilkCa: 150-300mg/dBiologiccontrolsystemforhomeostasis(体内平)ofCaVit.Dand甲状旁腺): renalreabsorption↑Calcitonin(降血钙):inhibitingbonelossandincreasingurineCalmodulin(钙调节): regulatingtheCainthecell.DRIsofCaEstimatingDRIs（膳食参考摄入量）Infants: meanintakeofbreast母乳)Others: Cabalancetest()DirectmeasureDRIs(mg/d)Dietarysourcemilk,smallshrimps(小虾),kelp(),legumes(豆类):soybeansoyabean(),redbean(红豆),sesamepaste(),andmanyCasupplements().Bodyiron

Iron(铁)Bodyiron(4-5g)FunctionalFe(75%): StorageFe(25%):PhysiologicfunctionsImportantroleinoxygenandelectrontransportOthers:catlyzingcarotene Vit.A;promotingproduceofantibody;lipidstransportinblood;detoxifyingdrugsinliver---AbsorptionandMetabolismAbsorptionofnonheme)factorsofdecreasingabsorptionrapidtransittimeachylia(),malabsorptionsyndromesprecipitation()byalkalinization(碱化),phosphatesphytates(),oxalate(草酸)andantacids(抗酸剂)irondosage3.12 factorsofincreasingabsorptionirondosagevit.C,B2;aminoacids:cysteine()MFPfactor(meatfishpoultry)Ca,Fehelpeachothertodiminishtheinhibitorsabsorptionofheme)The absorptionis not influenced by inhibitors whichdecrease absorptionofnonhemeiron.absorptionrateofironinthefoodsrice 1% corn 3% blackbean 3% lettuce4% flour 5%soybean 6% fish 11% hemoglobin 15% mustle,liver 22%iron-deficiencyanemiairon-deficiencyanemiaChina:40%0fchildrenunder3World: >4y, 0.6%-7.7%5-8y, 5.5%younghealthywomen 35%-58%Reason﹡Poordiets﹡Poorabsorption﹡Bloodloss:menstruation(月经),hemorrhage(出血),0.5mgFepermlblood.﹡PregnancyTheprocessassessmentofiron-deficiencyanemia(IDA)firststage irondecrease(ID):storedironexhaustion,ferritin↓.Secondstage Iron-deficiencyinerythrocytosis(serumFeandferritin↓,iron-bidingcapacity↑(saturationoftransferrin↓,),cons.0ffreeerythrocyteprotoporphyrin(FEP)(离原扑啉)↑ThirdstageIDA:hemoglobinandhematocritevaluesdecline.Deficiencysymptoms＊Immunesystem:Reducedresistancetoinfection(loweredimmunity)＊Nervous/Musculesystems:Reducedworkproductivity,tolerancetowork;Reducedphysicalfitness(健康)＊Skin:itching(痒);palenailbed(指甲床),eyemembranes,andpalmcreases(掌心起皱);concavenails(凹面指甲);impairedhealing().＊General:Reducedresistancetocold,inabilitytoregulatetemperature,pica(clayeating,iceeating)（异食癖）DRIs＊men:15mg/d ＊women:20mg/d＊pregnancy25-35mg/d＊wetnurse25mg/dFoodsourceIodine（碘）1 Iodineinthebody(20-50mg)tetraiodothyronine(T4),16.2%(甲状腺素)thyroid triiodothyronine(T3),7.6%(三碘甲状腺原氨酸iodine(8mg) diiodothyronine(DIT),33.4%(二碘酪氨酸)monoiodothyronine(MIT),32.7%(一碘酪氨酸)othersInblood: protein-bindingiodine,30-60μg/Lfunction:thyroxin(T)(甲状腺素)4regulatingoxidationreactionsincellsandenergymetabolism.Regulatingproteinsynthesisbylinkingtotheprocessesgeneticcontrolinthenucleus.Promotingthesynthesisofcholesterol,intestinalabsorptionofcarbohydrateandconversionofcarotenetoVitA.Regulatingthemetabolismofwaterandelectrolyte.Influencing the growth and development,and development.(15%mentalretardationinIDareainchina)absorptionandmetabolismiodinedeficiency IDDAdults:goiterTeenagers:influencinggrowth,developmentofbodyandmental.Infants:dementiaSupplementofiodide:iodizedsaltKI:1:KIO:1:20000~500003effectsofexcessiodine iodinegoiter6.DRIs＊adults: 150ug/d＊pregnancy 175ug/d＊wetnurse 200ug/dUL 850ug/d7.dietarysource:seafoodskelp24mg/100g seaslug(海)0.6mg/100gmussel(淡)1mg/100g 紫菜)1.8mg/100gzincinthebody(2-3g)

Zinc肝、脾、肌肉、骨骼、眼中较多blood(900ug/100ml)foundinallhuman prostate(前列腺)tissues(10-200ug/g) prostaticsecretionsspermatozoafunctionsandzincdeficiencyessentialconstituentofover100enzymes,ineachofthe6enzymecategoriesInfluencinggrowth,development andsexualsystem.involvingthesynthesisofDNA,RNAprotein(anorexiatogrow,testicularatrophy睾丸萎缩,skinlesions)Havingnormalappetite.PromotingmetabolismofVitA.Maintainingthereproductionofimmunecells.Involvinginneoplasticprocesses.metabolism(shorten)DRIsanddietarysourceDRIs:dietarysource:seafoodsandmeats.Seinthe

SeleniumInvariousamountsinalltissuesofthebodyexceptfatBodysize thehighestconcentrationisinliver,(14-20mg) kidney and spleenbloodSeis0.22ug/mlfunctionandSedeficiencyaconstituentofglutathioneperoxidase(GSH-Px),antioxidantanticancer.Detoxification:heavymetals,AFB.1Anticarcinogeniceffect:skin,liver,colon,breast,etal.Enhancementofhumoral,cell-mediatedandnonspecificimmunity.(5)Maintainheartandcardiovascularstructureandfunction(6)Keepingnormalgrowth(7)reducingfreeradicalreactionandextendinglifespan.toxicity:gastrointestionaldisturbances,badteeth,yellowskin,cardiorenaldisease.4.DRIs:50ug/d5.foodsource:animalfoodandseafood.Secontentoffooddependsonthesoilinwhichthefoodwasgrown.OtherelementsMg,Cu,Cr,Ni,Co,Mo,Mn,etal.(omit)[第六节维生素Section6Vitamins]一．目的和要求维生素来源和供给D，E，烟酸等有关内容。B6，叶酸等有关内容。二．重点和难点A，B1，B2；CA三、教学安排教学时数：1.5学时四、教学方法重点讲授，复习、提问、讨论相结合。应用多媒体课件。五、授课内容PrefacedefinitionAredistributedinnaturalfoodstuffsbutdistinctfromthemaincomponentsoffood(proteins,etal)(quantity,energy,componentofbody).Areessentialforbodymetabolisminminutequantitiesandabsenceanyoneofwhichcausesacorrespondingspecificdeficiencydisease.(3)CannotbesynthesizedinthebodyexceptVitD.classification:(1)theorderofdiscovery:A,B,C,D……(2)function:ascorbicacid(3)chemicalconstruction:popular(local)name:riboflavin……(4)solubility:water-soluble:B,C—excessesareexcretedintheurinefat-soluble:A,D—largeamountaretoxic.deficiencyofvitamins(1)cause:deficientintakesproblemofabsorptionincreaseinrequirement(2)deficiency:criticaldeficiency: diseasemarginaldeficiency:influencehealthwithoutsymptoms维生素A(VitA)retinal(A1)VitA–retinol s-dehydroretinal(A2)β-carotenestructuresandproperties:propertiesofVitAsolubility:solubleinfatsandalltheusualorganicsolvents,insolubleinwater.Oxidation: be oxidated by light,air and oxidant such asMnO

(Manganesedioxide).2Isomerization()：retinolisisomerizedbylightStability:sensitivetowardacidsbutstabletobase.Color reaction: retinal and its esters have a fluorescence(荧光。metabolism(1)absorption:smallintestine(2)transportandstorage：插图(3)excretion插图functioninvision:GeorgeWaldwasawardedtheNobelPrizeformedicine1967forhisdiscoveryoftheroleofVitAinthevisualsystem.插图effect on cell membrance:regulating membrance structure functionbyinfluencingthebiosynthesisofglycoproteinbecauseVitAisheadedforcarryingmono-oroligosacchrideunitstoanacceptorsite.Influencingthesynthesisofboneandbothserumandmuscleproteins.itinfluencethegrowth,developmentandreproduction.Againstcancer-roteneismoreimportant)deficiencynightblindnessandxerosis)xerosisoccursthroughoutthebodyinfluencingthegrowthanddevelopment(especiallybone,teeth)otherstoxicity(1)infants:transienthydrocephalus(暂时脑积水)andvomiting.(2)Adult(chromic):20-30timesofRDA.osteoclastsactivitiesincreasingothers:fetusdeformities,yellowskin,……estimationofnutritionallevelofVitAVitA level in plasma: 0.35~0.70umol/L (10~20ug/dL)–deficiency.butnormallevel(>30ug/dL)doesnotmeanthatVitAisenough.VitAstorageRBPinplasmaDarkadaptationPhysiologicblindpointDRIsandfoodsourceUnits: 1IURE1.0μgRetinol=1.0μgRE1.0μgβ-carotene=0.167μgREDRIs:Adults:800μgRE/dPregnancy:100μgRE/dWetnurse:1200μgRE/dfoodsource:β-carotene:inplant:vegetableandfruitswithpigments():spinach(),carrot(),sweetpotato(),persimmon(柿),apricot(杏),etal.VitA:liver,egg,milk.VitD(shortened)functionregulatingplasmaCaandPwiththeparathyroidhormoneCa,PabsorptionplasmaCa renalreabsorption plasmaCa,P Cafrombone facilitating(促进)mineralizationofthebone.Preventingricket,osteomalacia()andosteoporosis.DRIsanddietarysourceFoodsource:sameasVitAandsunlight.Vit.E(tocopherol,生育酚)Functionanddeficiencyreproductivesystem:male:degenerationofseminiferous(生精)epitheliumfemale:impairingvascularoffetalandplacenta asphyxia(息)anddeathoffetus.Noevidencetorelatemalfunctionofthereproductionprocessinman.muscularsystem:musculardystrophy()nervoussystem cerebellarencephalomalacia)vascularsystem:hemorrhages,peroxidehemolysis)biolodicantioxidant:keepthemembranestableothers:DNA and coenzyme Q synthesis,prevent synthesis N-nitrosamininstomach.DRIsandfoodsourcesDRIs:(mg-TE/d)foodsource:vegetableoilsVitB1

(thiamine)structureandpropertiesWatersoluble(1g/1ml水)；meltingpoint 248oC~250oC;at pH7,theabsorption maximum are at 235 and 267nm;at pH>7,easyoxidized.functionanddeficienxy,toxicity(1)functionthiaminintheformofpyrophosphate()participatesascoenzymeintheoxidativedecorboxylationofalphaketoacidtoaldehydes(醛)thiaminpyrophosphateasaenzymeinplantsandanimalsistransketolase.Others:influencingthefunctionsofnerve,heart,gastrointestinemaintainingappetitedeficiency:beriberidry(atrophic)beriberi:0.2~0.3mgB1

/1000calorieswetberiberi(subacute):<0.2mgB1

/1000calories.Neurologic,cardiovascularsymptomsaremoreapparent:edema,heartenlarged,tachycardia(心动过速),venouspressureincreased,digestivedisturbanceswithanorexia()andconstipation.cardiacfailuremayprecipitated().饮酒可加速缺乏toxicity:VitBproducesavarietyofpharmocologiceffectswhen1administeredindosesthousandsoftimeslargethanthoserequiredforoptimumnutrition.3.MetabolismnutritionalestimationtransketolaseactivityconcentrationofVitB1

inurineloadtest:5mgbymouthor1mgsubcutaneousinjection,determineurinin4hoursexcritionin24hoururine:difficult/ginosin(HxR)DRIsandfoodsourceDRIs(mg/d)foodsource:animal:viscera(internalorgans),meatplants:legumes(豆),peanut,cereals,yease.VitB(riboflavin)2structureandWatersoluble(slight):12mg/100mlHOat27.5oC2StabletoacidUnstabletobase,lightVitB-proteinorphosphateinfoodsarestablefunction,deficiencyandtoxicityfunction:Essentialforoxidativeenzymesystemsinvolvedinelectrontransport,includingtheAAoxidases,)Oxidase,succinic(琥珀酸)dehydrogenase,glutathionereductaseand2conenzymes:flavindinucleotide(FAD).deficiency:

mononucleotide(FMN), flavin adenineEye:vascularizationofcornea,darkadaption)Mouth:stomatitis(),glossitis()(maptongue)Skin:seborrheicdermatitis()aboutnoseandscrotum(囊)inmenandorogenital)inwomen.Animea:influencingtheabsorption,transportandstorageofiron.Others:influencingthegrowth,developmentandreproductiontoxicity:ratLD :560mg/kgB.W lowtoxicity50MetabolismestimationEGR):VitB2

inurineDRIsandfoodsources(1)DRIs(2)Foo