维生素A缺乏对大鼠铁营养状况的影响

目的 研究维生素A(VA)缺乏对大鼠铁营养状况的影响及其可能的机制。方法 雄性Wistar大鼠40只．按体重随机分为IVA和铁缺乏组，ⅡVA完全缺乏组，ⅢVA轻度缺乏组，Ⅳ VA正常对照组。实验动物喂饲8周后处死，测定血清VA、血清铁、铁蛋白、血红蛋白、肝内总铁含量，并用逆转录一聚合酶链反应(RT-PCR)法检测各组大鼠肝脏转铁蛋白mRNA的表达情况。结果 维生素A缺乏显地降低血清铁蛋白、血红蛋白和肝内总铁含量。抑制肝脏转铁蛋白mRNA的表达。结论 维生素A缺乏可能通过降低肝脏转铁蛋白mRNA的表达水平从而抑制了铁的吸收和转运。     

学龄儿童维生素A营养状况及其与铁的相关性研究

为观察学龄儿童维生素A(VA)营养状况、亚临床VA缺乏患病率及VA与铁的相关性 ,对北京房山山区 1 0 1 2名 7～ 1 3岁学龄儿童进行膳食调查 ,随机抽取 30 5名儿童 ,静脉采血于避光下分离血清 ,用高效液相色谱法检测血清VA含量 ,同时测定其血清铁蛋白 (SF)、红细胞游离原卟啉 (FEP)和血红蛋白 (Hb) ,并依现行标准将其分为正常、铁缺乏 (ID)、红细胞生成缺铁期 (IDE)与缺铁性贫血 (IDA)四组 ,观察VA与铁的相关性。结果显示受检儿童膳食总能量、蛋白质和铁平均每日摄入量均达到膳食营养素的推荐摄入量 (RNI)及适宜摄入量 (AI) ,但平均每日VA摄入量为 (51 3 7± 2 86 1 ) μgRE ,仅占RNI的 59 7% ;血清VA平均含量为(1 0 1± 0 2 9) μmol L ,血清VA低于 1 0 5μmol L者占受检儿童的 59 0 % ,其中 1 2 8%的儿童血清VA低于0 70 μmol L ,正常及以上者仅占 41 0 %。并观察到血清VA含量与机体铁状况有相互随对方下降而减低的趋势。结果表明 ,该地区儿童存在明显的VA缺乏 ,应加强营养教育、改善不合理的膳食结构并通过适当的VA防治予以纠正     

补充维生素A对健康成人铁营养状况的影响

目的观察健康成人补充维生素A(VA)后铁营养状况的变化。方法选择115名健康成人志愿者,按血清视黄醇浓度用区组设计方法将男女志愿者随机分入4组(男、女各半),在日常膳食的基础上,分别补充不同剂量的VA,干预剂量(以视黄醇计)分别为600μg/d(A组)、400μg/d(B组)、200μg/d(C组)和0μg/d(D组),干预期4个月。补充剂为微胶囊化的视黄酰乙酸酯,将5日剂量装入1粒胶囊,每5日口服1粒。胶囊外包装只标注剂量类型,现场实验人员和受试者均不知道每一种胶囊的补充类型。干预期内,受试者接受常规膳食,每月进行1次24h回顾性膳食调查。干预试验前后,采集空腹上臂静脉血,取血清测定血液血红蛋白(Hb)浓度,血清视黄醇、血清铁(SI)、铁蛋白(SF)和转铁蛋白受体(TfR)浓度。结果共有108名受试者完成干预试验,A、B、C和D组各为27、28、27和26名。干预期内,4组受试者膳食能量营养素、视黄醇当量(RE)和铁摄入量无显著性差异(P>0.05)。干预结束后,A组受试者血清视黄醇浓度从干预前的(1.63±0.55)μmol/L升高到了(1.93±0.52)μmol/L(P<0.05);B和C组血清视黄醇浓度分别平均升高了0.29μmol/L和0.14μmol/L(均为P<0.05);而对照组D组变化不显著(P>0.05)。干预试验前后各组Hb差异没有显著性(P>0.05);高剂量VA组受试者干预后SI浓度比干预前显著升高,而SF和TfR浓度则显著降低(均为P<0.05);中剂量组和低剂量组在干预前后SF和TfR未见显著性变化。结论铁营养状况正常的成人,在没有专门给予膳食铁干预的情况下,通过较大剂量VA补充干预,铁营养状况仍然得到进一步提高。     

儿童维生素A与铁营养状况的相关性研究

目的了解中国儿童维生素A(VA)的营养状况、VA缺乏率、VA边缘缺乏率,研究血浆VA与铁营养状况的相关性。方法由2002年“中国居民营养与健康状况调查”的大样本中随机抽取380名3~12岁儿童,检测血浆VA含量,同时测定血红蛋白(Hb)、总铁结合力(TIBC)、铁蛋白(SF)及转铁蛋白受体(sTfR)。了解儿童VA营养状况,计算VA缺乏率、VA边缘缺乏率,研究VA与铁营养状况评价指标的相关性。结果受试儿童VA平均含量为(1·03±0·24)μmol/L,其中8·4%儿童VA缺乏,44·7%儿童VA边缘缺乏。血浆VA与Hb呈正相关(r=0·16986,P<0·01),与sTfR呈负相关(r=-0·12863,P<0·05),与TIBC、SF不相关。结论铁缺乏伴随VA边缘缺乏在中国儿童中普遍存在,VA与铁营养状况存在相关性。     

The Influence of Vitamin A Supplementation on Iron Status

Vitamin A (VA) and iron deficiencies are important nutritional problems, affecting particularly preschool children, as well as pregnant and lactating women. A PubMed (National Library of Medicine, National Institutes of Health, Bethesda, MD, USA) literature review was carried out to search for clinical trials published from 1992 to 2013 that assessed the influence of vitamin A supplementation on iron status. Simultaneous use of iron and vitamin A supplements seemed to be more effective to prevent iron deficiency anemia than the use of these micronutrients alone. Some studies did not include a placebo group and only a few of them assessed vitamin A status of the individuals at baseline. Moreover, the studies did not consider any inflammatory marker and a reasonable number of iron parameters. Another important limitation was the lack of assessment of hemoglobin variants, especially in regions with a high prevalence of anemia. Assessment of hemoglobin variants, inflammatory markers and anemia of chronic inflammation would be important to the studies investigated. Studies involving different populations are necessary to elucidate the interaction between the two micronutrients, especially regarding iron absorption and modulation of erythropoiesis.     

肺炎患儿治疗前后血清维生素A营养状况及铁含量的变化

目的探讨分析肺炎患儿治疗前后血清维生素A营养状况及铁含量的变化,为其临床治疗提供新的思路。方法选取2013年12月-2014年12月延安大学附属医院儿科收治的80例临床确诊为肺炎住院的患儿为肺炎组,分为常规治疗组和维生素A治疗组;另抽取同期健康体检儿童30例为对照组,对肺炎患儿入院后24h内和住院治疗10d后,对照组于体检当天给予采血检测视黄醇结合蛋白和血清铁含量,并对检测结果进行对比。结果肺炎组所有患儿入院后24h内视黄醇结合蛋白和血清铁含量明显低于对照组,差异有统计学意义(P0.05),而肺炎常规治疗组与维生素A治疗组视黄醇结合蛋白和血清铁含量比较差异无统计学意义(P0.05)。肺炎组住院后10d视黄醇结合蛋白和血清铁水平明显上升,肺炎常规治疗组与对照组比较差异仍有统计学意义(P0.05),维生素A治疗组较对照组比较差异无统计学意义(P0.05)。结论肺炎急性期存在显著的维生素A缺乏和血清铁含量下降,随着肺炎病情的好转,维生素A缺乏和血清铁含量下降逐渐上升,维生素A缺乏与小儿肺炎的发生及病情发展存在一定的关系,在肺炎的治疗过程中应注意维生素A的补充。     

铁缺乏对大鼠维生素A代谢的影响

目的研究铁缺乏对大鼠维生素A(VA)代谢的影响。方法44只雄性SD大鼠按体重随机分为4组,每组11只,正常对照组(Ⅰ组),Fe完全缺乏VA正常组(Ⅱ组),Fe轻度缺乏VA正常组(Ⅲ组),Fe和VA轻度缺乏组(IV组)。喂饲10周后处死,测定血清视黄醇、血清视黄醇结合蛋白(RBP)、血红蛋白(Hb)、血清铁、血清铁饱和度、肝脏VA含量,肝脏视黄基酯含量,并用逆转录-聚合酶链反应(RT-PCR)法检测各组大鼠肝脏RBP mRNA的表达。结果与对照组相比,铁缺乏可以使血清视黄醇、肝脏VA含量显著降低(P<0.05),使肝脏视黄基酯与肝脏VA的摩尔比值升高,使RBP含量有降低趋势,铁缺乏时肝脏RBP mRNA表达显著降低。结论铁缺乏可能通过影响维生素A吸收、储存、转运来影响体内维生素A的营养状况。     

维生素A缺乏对大鼠铁代谢影响

目的 研究维生素A(VA)缺乏对大鼠铁营养状况和肝脏转铁蛋白受体(TfR)mRNA表达的影响.方法 雄性SD大鼠52只,按体重随机分为4组,每组13只,Fe和VA正常对照组(I组),Fe正常VA完全缺乏组(II组),Fe正常VA轻度缺乏组(Ⅲ组),Fe和VA轻度缺乏组(IV组).喂饲8周后处死,测定血清VA、血红蛋白、血清铁、血清转铁蛋白受体、血清铁蛋白、肝脏铁含量,脾脏铁含量,并用逆转录聚合酶链反应(RT-PCR)法检测各组大鼠肝脏转铁蛋白受体(TfR)mRNA的表达.结果 结果与对照组比较,VA缺乏使血清铁、血清铁蛋白含量显著降低(P<0.05),血清转铁蛋白受体水平、脾脏铁含量显著升高(P<0.05),VA缺乏时肝脏TfRmRNA表达显著增强.结论 维生素A缺乏可能通过影响铁吸收、储存、转运变改体内铁的营养状况,VA缺乏时,肝脏可能通过铁调节蛋白(IRE-ⅠRP)途径使TfR mRNA的表达水平增加.     

维生素A在铁缺乏及缺铁性贫血治疗中的作用

近几年研究发现维生素A缺乏与铁缺乏具有显著的相关性,维生素A治疗缺铁性贫血和铁缺乏也取得了较好的临床效果.本文就维生素A缺乏与铁缺乏的相关性和作用机制,以及维生素A治疗缺铁性贫血的临床疗效和研究进展进行了综述,为维生素A用于儿童缺铁性贫血的防治提供依据,同时为降低我国儿童缺铁性贫血及铁缺乏的发病率提供更有效的防治措施.     

急性时相反应对学龄前儿童维生素A与铁评价指标的影响

【目的】了解急性时相反应对学龄前儿童维生素A和铁状况评价指标的影响。【方法】检测385名学龄前儿童血清视黄醇、铁蛋白、血红蛋白以及C-反应蛋白(C-reaction protein,CRP)水平并分析指标间内在关系。【结果】不同CRP水平儿童的血红蛋白浓度无明显差异(P0.05),CRP≥10 mg/L儿童血清视黄醇浓度明显低于CRP10 mg/L儿童,铁蛋白则相反(P0.05)。CRP≥10 mg/L儿童维生素A不足发生率显著高于CRP10 mg/L儿童。调查对象维生素A不足发生率为34.03%,但1.56%儿童伴感染;铁储备正常率为53.25%,但3.12%儿童伴感染。【结论】急性时相反应对维生素A和铁等营养评价指标有明显影响,人群营养评价应同时考虑感染的影响。     

维生素A缺乏对大鼠铁调节蛋白2影响

目的 探讨维生素A缺乏对大鼠铁调节蛋白2(IRP2)mRNA及铁蛋白(Fn) nRNA和转铁蛋白受体(TfR)mRNA表达影响.方法48只雄性SD大鼠按体重随机分为4组,每组12只,对照组、维生素A完全缺乏组;维生素A边缘缺乏组;铁及维生素A边缘缺乏组;喂养8周后,麻醉处死大鼠,取组织和血清,进行相关指标和基因表达检测.结果与对照组( 1.50 +0.41) μmol/L比较,维生素A完全缺乏大鼠血清维生素A(0.22±0.26) μmol/L水平明显降低(P＜0.05);与对照组比较,维生素A完全缺乏组大鼠血清铁(2.26 +0.72)lμg/mL明显降低;维生素A完全缺乏组大鼠肝脏IRP2、TfR表达水平分别为(1.53±0.18)、(0.62±0.06)与对照组相比明显升高,FnmRNA (0.52±0.08),明显低于对照组(P＜0.05).结论维生素A缺乏通过改变IRP2表达、IRP-RNA结合活性,在转录后水平改变TfR和Fn mRNA表达,影响铁稳态.     

贫血孕妇维生素A、维生素B_2和铁营养状况及抗氧化水平的调查分析

目的分析孕期贫血妇女的血浆维生素A(VA)、维生素B2(VB2)和铁营养状况及抗氧化水平。方法将孕中期妇女分成非贫血组(Hb≥110g/L,36人)和贫血组(HB80~105g/L,426人),经知情后同意参加。采用24小时膳食回忆法了解受试者每日主要营养素摄入情况,采集空腹静脉血5ml,分析血浆VA、VB2和铁蛋白(SF)水平,超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性,丙二醛(MDA)和红细胞膜流动性的变化。结果贫血孕妇VA、VB2摄入不足,分别为推荐摄入量(RNIs)的58·7%和57·2%,铁的来源仍为吸收率低的植物性食物。贫血孕妇的血浆VA(1·25μmol/L)和铁蛋白(20·57μg/L)水平明显低于非贫血孕妇(VA1·57μmol/L,SF33·16μg/L,P<0·05),全血谷胱苷肽还原酶活性系数(BGRAC)(1·79)水平高于非贫血组(1·52);SOD(77·1U/ml)和GSH-Px(61·9U)活性低于非贫血组(SOD92·2U/ml,GSH-Px71·6U,P<0·05);MDA(4·58nmol/ml)和红细胞膜的P和η值(P=0·2622,η=2·7465)明显高于非贫血组(MDA3·78nmol/ml,P=0·2360,η=2·3658,P<0·05)。且随贫血程度的加重,VA、铁蛋白水平、SOD和GSH-Px活性进一步下降,BGRAC、MDA、P和η值明显升高。结论妊娠中期贫血妇女血浆VA、VB2、铁蛋白及抗氧化能力均明显低于非贫血孕妇。且随贫血程度的加重而降低。     

贫血孕妇铁与维生素A营养状况分析

目的 了解妊娠妇女铁、维生素A、核黄素等营养素的摄入及贫血的患病情况，为开展营养干预提供科学依据。方法随机抽取山东省莘县430名贫血孕妇和292名非贫血孕妇，采用24h回顾法比较2组孕妇主要营养素摄入情况，分析孕妇维生素A、核黄素及铁的营养水平。结果2组孕妇膳食均以粮谷类等植物性食物为主，铁的摄入量接近膳食推荐摄入量（RNIs）；血清检验结果显示，贫血组的铁营养水平明显低于非贫血组；85．2％贫血孕妇血浆铁蛋白〈14μg／L，转铁蛋白受体平均为31．42nmol／L；贫血组缺乏维生素A和核黄素的比例分别为62．9％和63．1％，明显高于相应的非贫血组（P〈0．01）。结论贫血不仅与铁的吸收利用率有关，而且与维生素A、核黄素摄入不足或缺乏有密切关系。     

补充富含类胡萝卜素的蔬菜对儿童维生素A营养状况的影响

于１９９６年９月～１２月在山东省泰安市某幼儿园的两个班使用富含类胡萝卜素的蔬菜进行了干预试验。所选择两个班４１名儿童的平均年龄为５．３～６．５岁,其中３９％的儿童血清视黄醇低于０．３０ｍｇ／Ｌ,处于边缘缺乏状态。分为２个组：对照组,不改变日常膳食,平均每日每人摄入１９３ｇ浅色蔬菜（圆白菜、大白菜、土豆、黄瓜、菜花和白萝卜等）和５６ｇ黄绿色蔬菜（菠菜、空心菜、胡萝卜和红心红薯等）;试验组,平均每日每人摄入２３８ｇ黄绿色蔬菜和３４ｇ浅色蔬菜。结果表明膳食中黄绿色蔬菜对改善学龄前儿童的维生素Ａ营养有重要影响,且安全、廉价。     

Influence of dietary and socio-demographic factors on the iron status of married adolescent girls from Indian urban slums

To explore the influence of dietary factors of iron bioavailability and socio-demographic conditions on blood iron status of married adolescent girls (MAG), a cross-sectional study was conducted in 173 MAG (15–19 years old) from urban slums near Pune city, India. Diet was assessed by two random 24-h recalls. The age, weight, height, education, family size, income, physical work, and number of days of menstrual loss were recorded. Fasting blood was analyzed for hemoglobin and serum ferritin. Mean intakes of micronutrients were 40–75% less than the recommended dietary intakes for Indian adolescent girls. High intake of phytates (171±6 mg/day) and low intakes of vitamin C (25±1 mg/day) resulted in low bioavailable iron intakes. The mean bioavailable iron intake was 0.76±0.3 mg/day, which is one-half of the basal iron requirement of adolescent girls. The prevalence of iron deficiency (serum ferritin<12 µg/l) was 25.1%, and anemia (hemoglobin <12 g/l) was seen in 46.4% of MAG. A multiple regression model adjusted for energy intake indicated that intakes of β-carotene and riboflavin were associated with hemoglobin (P<0.001) and those of zinc, riboflavin and thiamin associated with serum ferritin (P<0.01). Multiple regressions including socio-demographic factors revealed that the family size, number of menstrual days lost and total bioavailable iron intake were the influencing factors for low iron status. In conclusion, there is a need to increase intakes of vitamin C and other micronutrients of the MAGs and to improve iron bioavailability through diet modifications.     

城市居民维生素A营养状况调查

目的评价城市居民维生素A营养状况。方法在浙江2城市按多阶段整群随机抽样方法,抽取400名居民,通过问卷调查和3天24小时膳食调查法、体格检查和血样采集检测血清维生素A水平,采用维生素A每日推荐摄入量(RNI)来评价维生素A膳食摄入状况,分析城市居民维生素A营养状况及其影响因素。结果城市居民维生素A水平中位数为0.463(0.213)μg/m L,维生素A高度缺乏的占0.25%、缺乏的占0.50%、不足的占6.75%、充足的占92.50%。299人参与了膳食调查,每日维生素A摄入量的中位数为350.5(351.5)μgRE;平均每日维生素A摄入量低于60%RNI的占61.87%,仅有25.42%的人摄入量在80%RNI以上。男性、大城市、年龄较大、血清甘油三酯水平较高及膳食胆固醇摄入较高的居民其血清维生素A水平较高。结论城市居民血清维生素A较为充足,但维生素A膳食摄入状况仍有待改善。年龄、性别、地区等因素影响血清维生素A水平。     

中国儿童维生素A缺乏与贫血关系分析

【目的】了解维生素A(VA)缺乏和贫血之间的关系。【方法】全国分层抽取14个省42个市县的8699名6岁以下儿童，血清维生素A和血红蛋白的测量，分别采用荧光法及Hemocue System血红蛋白测定仪。【结果】血红蛋白正常、轻度、中度和重度贫血组儿童VA缺乏率分别为10．8％，18．7％，23．2％，42．9％．随血红蛋白水平下降显著增加。VA正常、VA可疑缺乏及VA．缺乏组儿童贫血患病率分别为6．1％，12．7％，17．1％。随血清VA水平下降不仅贫血患病率增加，而且贫血严重度增加。【结论】VA和铁之间可能存在着相互影响。     

A lowering effect of a pharmacological dose of vitamin E on serum vitamin a in normal adults

We have studied the effects of oral vitamin E (vE) on serum vitamin A (vA) levels and vA transport proteins, retinol binding protein (RBP) and prealbumin (PA), in normal subjects taking and not taking pharmacological doses of vA and/or vE acetate. Nineteen subjects were given 9009 ug of oral vA acetate daily for one week. Ten of these continued on 9009 ug of vA daily for two weeks (group I), while nine received 147 mg of vE acetate in addition to vA (group II). A third group (group III) consisted of 10 subjects who received only 147 mg of vE daily for 3 weeks. Group IV represented control subjects not given either vA or vE pills over the 3 week study period. Groups I and II showed significant increases in serum vA levels after 1 week of vA treatment. Group I to week 3 (p<0.01) while group II serum vA levels significantly fell from week 1 to week 3 (p<0.01). No significant differences were demonstrated in RBP or PA in groups I and II. Group III showed a significant fall in serum vA and RBP levels from initial to week 3 (p<0.005) with no significant change in PA. Control subjects (group IV) showed no significant variation of any parameter over the three week test period. The fall in serum vA and RBP seen among our subjects taking vE alone is consistent with either enhanced hepatic vA uptake or increased vA transport to and utilization by peripheral tissues.     

维生素A营养状况的评价方法

维生素A是人体必需的营养素之一。在世界范围内严重的维生素A缺乏已经得到有效控制的情况下,“亚临床状态”的维生素A缺乏依然是许多国家,尤其是发展中国家所面临的公共卫生问题。准确地评价高危人群的维生素A营养状况对于研究临床和亚临床维生素A缺乏对人体健康的影响以及营养干预策略的制订和实施有着极为重要的意义。目前用于评价人体维生素A水平的指标包括临床症状、组织学指标、功能指标和生化指标等。     

Nutritional vitamin A status in northeast Brazilian lactating mothers

Background: Vitamin A deficiency is the major cause of morbidity and mortality among children and in women of reproductive age in developing countries. The present study aimed to assess maternal nutritional vitamin A status, as well as analyse the association of preformed vitamin A and pro‐vitamin A consumption on the nutritional status of nursing mothers, based on serum retinol and retinol colostrum concentrations coupled with dietary intake. Methods: Serum and colostrums were collected from 86 healthy parturients, recruited within 16 h postpartum. Blood samples were obtained, the morning after an overnight fast. Retinol was analysed by high‐performance liquid chromatography. Dietary vitamin A was assessed using a food frequency questionnaire and the women were separated into two groups according to the predominant dietary source of vitamin A: group A, >50% preformed vitamin A (n = 37); and group B >50% pro‐vitamin A carotenoids, (n = 49). Results: Serum retinol and total vitamin A ingestion (mean ± SD) were higher in group A than in group B (1.4 ± 0.4 μmol L^?1 and 2072.0 ± 1465.9 μg retinol activity equivalent (RAE) day^?1 versus 1.2 ± 0.6 μmol L^?1 and 1051.6 ± 920.4 μg RAE day^?1, respectively (P < 0.05), but colostrum retinol (3.4 ± 1.7 μmol L^?1 and 3.6 ± 1.9 μmol L^?1) was similar in both groups. In group B, 36.7% (n = 18) of the nursing mothers presented a risk of developing vitamin A deficiency, based on their dietary intake. Conclusions: On the basis of the intake of the pro‐vitamin A carotenoids, some women may be at risk of vitamin A deficiency. However, their status is currently normal, as indicated by serum and milk retinol concentrations.