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。     

2型糖尿病患者血清丙二醛及谷胱甘肽过氧化物酶测定

目的探讨2型糖尿病与谷胱甘肽过氧化物酶(GSH-Px)及丙二醛(MDA)的关系.方法检测89例2型糖尿病人与112例正常对照组血清中MDA与GSH-Px含量和活性.结果2型糖尿病患者血清MDA含量4.79±0.41μmol/L,GSH-Px活性115.3±10.7 U/0.1ml.正常对照组MDA 3.83±0.42μmol/L,GSH-Px145.72±12.5 U/0.1ml.两组比较P均＜0.01.结论2型糖尿病患者MDA含量明显高于对照组,而GSH-Px活性明显低于正常对照组.     

维生素C对大鼠肌肉拉伤所致过氧化损伤的保护作用

目的建立骨骼肌拉伤动物模型,观察维生素C对肌肉拉伤导致的过氧化损伤的保护作用.方法将大鼠随机分为维生素C组、生理盐水(NS)组及对照组.利用大鼠建立骨骼肌拉伤动物模型,将维生素C组及NS组造成大鼠右侧腓肠肌拉伤.维生素C组经灌胃给予维生素C(2 g·kg-1·d-1),NS组给予同体积生理盐水,观察损伤后3、7、14 d大鼠血浆中肌肉损伤标志物肌酸激酶(CK)活力和丙二醛(MDA)含量、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活力以及总抗氧化能力(T-AOC)的变化.结果维生素C组血浆CK活力在伤后3、7、14 d[分别为(325.36±28.29)、(147.06±27.40)、(80.47±13.50)U/L]均低于NS组[分别为(403.67±25.17)、(193.03±26.31)、(92.98±8.93)U/L],差异均有显著性(P＜0.05).维生素C组血浆MDA含量在伤后3、7d[分别为(8.03±2.22)、(5.33±1.54)μmol/L]低于NS组[分别为(13.81±3.17)、(7.55±2.20)μmol/L].维生素C组SOD活力较NS组有升高趋势,且在第7天明显高于NS组[维生素C组为(104.33±11.56)NU/ml,NS组为(86.85±14.25)NU/ml],差异有显著性(P＜0.05);维生素C组GSH-Px活力、T-AOC在伤后3、7、14 d均高于NS组,差异亦有显著性(P＜0.05).结论本研究所用剂量的维生素C减低了腓肠肌拉伤所引起的氧化性损伤程度,并使两种抗氧化酶(SOD、GSH-Px)活力明显升高,且血浆总抗氧化能力明显增强.     

维生素A干预对大鼠抗氧化能力及细胞膜流动性影响的研究

目的　通过对大鼠补充不同剂量维生素A(VA)观察机体抗氧化能力及对红细胞膜流动性的影响 ,了解抗氧化活性的最佳剂量。方法　将Wistar大鼠随机分为 4组 ,分别为维生素A缺乏组 (VA1组 )补充1 1 4 3(VA2组 )、4 2 86 (VA3组 )和 1 4 2 86 μgRE·kg- 1 ·d- 1 (VA4组 )维生素A三个剂量组。测定各组大鼠血浆VA含量、SOD、MDA和GSH Px的含量和活性 ,用荧光偏振度P值和微粘度 η值评价红细胞膜的流动性。 结果　各组血浆中VA水平随补充剂量的增加而增加。血浆中SOD、GSH -Px和MDA的结果显示 ,补充剂量为VA2、VA3组SOD的水平较VA缺乏组和VA4组明显偏低 (P <0 0 1 )。VA3组的MDA较其它 3个剂量组明显下降 (P <0 0 1 )。VA4组的SOD、MDA含量明显高于其它三个剂量组 (P <0 0 1 )。VA3组血浆中GSH -Px的活性明显升高 ,P <0 0 1。细胞膜流动性的结果显示 :VA3组P值最小 (P <0 0 1 ) ;VA4组P值明显增高 (P<0 0 1 )。微粘度 η在VA3组与VA缺乏组和VA2组之间未见明显差异 ,与VA4组相比明显下降 (P <0 0 1 )。结论　维生素A补充剂量为 4 2 86 μgRE·kg- 1 ·d- 1 时 ,能够发挥较好抗氧化作用 ,红细胞膜的流动性明显增加 ,过量摄入维生素A可造成机体的中毒反应 ,增加机体的氧化损伤     

天津市90例孕妇、新生儿维生素A和维生素E的营养状况

于1984年5月至1985年2月追踪研究了天津市90例正常孕妇妊娠中、后期母血、分娩时脐血维生素A(VA)、维生素E(VE)水平及有关因素。结果表明,妊娠中、后期孕妇血清VA、VE浓度均显著高于非孕妇,并随着妊娠的进展呈进行性上升,孕中、后期母血VA的平均浓度分别是非孕妇的1.7倍和1.8倍(非孕妇为39.9μg/dl),VE的平均浓度分别是非孕妇的1.2倍和1.8倍(非孕妇为10μg/ml)。孕妇血VE水平与血胆固醇水平呈高度正相关。初乳VA平均含量为117.8μg/dl。脐血VA和VE的平均浓度均显著低于母血,分別是孕后期母血浓度的1/3和1/5。     

口服亚硒酸钠和维生素E对高海拔地区心血管病患者甲状腺激素的影响

目的探讨使用亚硒酸钠和维生素E对高海拔地区心血管病患者甲状腺激素的影响.方法将心血管病患者随机分为3组A组42例患者口服亚硒酸钠,同时加服维生素E;B组28例患者口服亚硒酸钠;对照组20例,未服用亚硒酸钠及维生素E.观察对象分别于治疗前和治疗6个月后抽血检测血清硒(Se)、血浆谷胱甘肽过氧化物酶(GSH-Px)活力、丙二醛(MDA)含量及甲状腺激素(T3、T4)等指标,以观察远期疗效.结果治疗后A组和B组血清Se含量[(0.71±0.22)、(0.68±0.18)μmol/L]明显高于治疗前[(0.31±0.17)、(0.33±0.14)μmol/L],差异有显著性(P＜0.01);A组和B组血浆GSH-Px活力分别为(87.12±13.61)、(84.79±12.13)U/L,较治疗前[分别为(58.43±18.93)、(57.12±17.36)U/L]明显增加.A组和B组MDA含量[(4.86±1.18)、(4.18±1.23)nmol/ml]较治疗前[(8.66±0.96)、(8.71±0.87)nmol/ml]明显降低,差异均有显著性(P＜0.01);A组和B组患者T3和T4较对照组明显降低,趋于正常.血清Se与血浆GSH-Px呈正相关(r=0.781,P＜0.01),与MDA、T3、T4浓度呈负相关(r=-0.385;r=-0.687;r=-0.412,均P＜0.05).甲状腺激素恢复正常者A组31例(73.81%)、B组20例(71.42%);部分恢复者A组4例(9.52%)、B组2例(7.43%),其恢复率明显高于对照组,差异有显著性(P＜0.05),远期疗效较好.结论补充适量硒和维生素E可纠正高原环境下因低Se而引起的甲状腺激素代谢异常.     

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和铁对孕妇铁营养状况的影响

目的　研究补充维生素 A、铁对孕妇铁营养状况的影响。方法　对 1 6 7名孕中期妇女进行铁和维生素 A营养状况的横断面调查并随机分成 4组 :对照组 (复合维生素 B片每日一片 ) ;补充维生素 A组 (1 1 0 0 μg/d) ;补充铁组 (6 0 mg/d元素铁 ) ;补充维生素 A和铁组 (VA1 1 0 0μg/d,Fe6 0 mg/d) ,共补充 1 0 w。结果　被调查孕妇孕中期维生素 A轻度缺乏率为 0 .6 % ,贫血患病率为 7.8% ,贮存铁缺乏率为 6 .2 %。血清 VA水平补充前各组正常 ,补充后对照组明显下降 ,但仍维持在正常范围。补 VA、补铁及补 VA+铁组血清 VA与补充前无明显差异 ,仍保持恒定。各组补充前后 Hb均在正常范围 ,差别不显著。血清铁蛋白、游离红细胞原卟啉及运铁蛋白饱和度补充后的改善效果均以补充 VA铁组优于单独补 VA或补铁组。结论　孕期同时补充 VA和铁对改善铁的营养状况优于单纯补铁。     

肺结核患者维生素A、维生素E和β-胡萝卜素营养状况及机体抗氧化酶水平分析

目的了解肺结核患者维生素A(VA)、维生素E(VE)和β-胡萝卜素(β-C)营养状况及机体抗氧化酶水平。方法随机抽取临沂市郯城县结核病防治所2010年就诊的70例肺结核患者作为病例组,匹配选取该地同期正常健康人群70例作为对照组。两组人群均进行相关营养指标检测,包括基本营养状况,如体质指数(BMI)、血红蛋白(Hb);血脂水平分析,如甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白(HDL);抗氧化酶水平分析,包括超氧化物歧化酶(SOD)和过氧化氢酶(CAT);机体VA、VE和β-C水平。结果病例组的BMI为19.13,明显低于对照组21.95(P<0.05),而病例组Hb为128.36g/L,低于对照组的131.30g/L,但差异无显著性。血脂水平分析显示病例组TG、TC和HDL含量分别为1.54、4.47和1.21mmol/L,均低于对照组相应的含量(1.63、5.20和1.30mmol/L)(P<0.05)。抗氧化酶水平比较显示病例组的SOD和CAT水平分别为78.20和5.24U/ml,对照组两者的水平分别为83.27和9.99U/ml,病例组明显低于对照组(P<0.05);维生素水平分析显示病例组的VA和VE含量0.256和1.148μg/ml,均显著低于对照组的0.385和1.182μg/ml(P<0.05),但病例组的β-C含量为0.048μg/ml,略低于对照组的0.051μg/ml,差异无显著性。结论肺结核患者的自身营养状况较差,体内抗氧化酶和VA、VE、β-C水平均显著低于正常人群。     

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。     

贫血孕妇营养状况及免疫水平的调查分析

目的检测贫血孕妇体内维生素A(VitA)、核黄素(VitB2)和铁(Fe)的水平,为在人群中科学合理地实施对VitA、VitB2和Fe的联合干预提供理论依据。方法随机抽取340名贫血孕妇和150名非贫血孕妇,采用24h回顾法进行膳食调查,并检测受试者体内VitA、VitB2和Fe的水平。结果贫血组孕妇膳食中VitA、VitB2的摄入量分别仅达到推荐量的52.08%和55.88%,明显低于非贫血组孕妇(P<0.01)。贫血组血清VitA、VitB2及Fe的营养状况、免疫指标均明显低于非贫血组(P<0.001)。而同时缺乏3种营养素的孕妇免疫球蛋白水平和淋巴细胞增殖活性明显低于缺乏某一种营养素的孕妇。结论贫血孕妇体内VitA、VitB2和Fe水平较低,由此可影响机体的细胞免疫和体液免疫功能,而3种营养素同时缺乏时影响更明显。     

Supplementation with iron and riboflavin enhances dark adaptation response to vitamin A-fortified rice in iron-deficient, pregnant, nightblind Nepali women

BACKGROUND: Nightblindness affects 16-52% of pregnant women in areas of Nepal and in some cases persists after vitamin A treatment. Iron and riboflavin affect vitamin A utilization and photoreceptor function, respectively, and pilot data in the study population showed a high prevalence of iron and riboflavin deficiencies. OBJECTIVE: The objective was to assess the effect of supplemental iron and riboflavin on pupillary threshold (PT) and plasma retinol in nightblind, pregnant Nepali women given vitamin A-fortified rice. DESIGN: Nightblind pregnant women were randomly assigned to receive, 6 d/wk under supervision for 6 wk, a vitamin A-fortified rice curry dish providing 850 microg retinal activity equivalents/d with either a 30-mg Fe and 6-mg riboflavin (FeR + VA) capsule or a placebo control (VA only) capsule. Hemoglobin, erythrocyte riboflavin, and plasma ferritin and retinol were measured before and after the intervention. Dark adaptation was assessed by PT score. RESULTS: Women who were iron deficient at baseline (n=38) had significantly greater improvement in PT score with iron and riboflavin supplementation than without (P=0.05). Iron and riboflavin supplements significantly reduced the prevalences of riboflavin deficiency (from 60% to 6%; P<0.0001), iron deficiency anemia (from 35% to 15%; P<0.007), and abnormal PT (from 87% to 30%; P<0.05) from baseline. Mean increases in erythrocyte riboflavin (P<0.0001) and plasma ferritin (P=0.01) were greater in the FeR + VA group than in the VA only group. CONCLUSIONS: Iron deficiency may limit the efficacy of vitamin A to normalize dark adaptation in pregnant Nepali women. Further studies are needed to assess the effect of simultaneous delivery of iron and vitamin A for the treatment of nightblindness.     

Response of hemoglobin, serum ferritin, and serum transferrin receptor during iron supplementation in pregnancy: a prospective study

OBJECTIVE: We evaluated the effect of iron supplementation on biochemical indicators of iron status, namely hemoglobin (Hb), serum ferritin (SF), and serum transferrin receptor (sTfR), during pregnancy. METHODS: A prospective study was conducted in 73 pregnant women who received daily supplements of 60 mg of iron and 500 microg of folic acid for 100 d from 19 wk of gestation. The indicators of iron status (Hb, SF, and sTfR) at 19, 27, and 35 wk of gestation were analyzed. The response of iron status indicators to iron supplementation was assessed in the cohort and in pregnant women who were anemic (n = 35) and non-anemic (n = 38) at 19 wk. RESULTS: All three indicators of iron status during supplementation (27 and 35 wk) were similar to the presupplementation status. The sTfR as an indicator correlated negatively with presupplementation Hb levels (r = -0.417). Based on sTfR level in iron-adequate pregnant women, a cutoff value of at least 12.0 mg/L was derived to define iron deficiency in pregnancy. When the response was tested in anemic pregnant women, iron supplementation improved mean Hb (P < 0.05) at the end of 35 wk (96 +/- 8.8 to 110 +/- 20.2 g/L) of gestation, with no change in SF. Conversely, non-anemic pregnant women showed a significant increase in SF and a decrease in Hb (122 +/- 11.6 to 112 +/- 15.2 g/L) at 35 wk of gestation. A significant effect of iron intake on sTfR was seen only among iron-deficient anemic women. CONCLUSIONS: These observations suggest that, during pregnancy, sTfR responds to iron supplementation when there is iron-deficiency anemia and therefore can be used as an indicator.     

维生素E补充对外周血细胞活性的影响及机制研究

目的观察不同剂量维生素E(VE)补充对大鼠外周血淋巴细胞增殖活性和抗DNA氧化损伤能力以及红细胞膜流动性的影响。方法将48只Wistar大鼠随机分为对照组和VE1、VE2及VE3三个VE补充组,各组VE摄入量分别为每天7.5、50、200和750IUkgbw,实验期为8周。实验结束后无痛处死动物并留取全血,分别测定血浆VE和MDA含量,分析红细胞膜GSHPx活性、红细胞膜流动性、淋巴细胞转化率及DNA氧化损伤。结果3个干预组血浆VE水平较对照组明显升高(P<0.05);50IUkgbw·dVE(VE1)组血浆MDA含量为(2.29±0.55)nmolml,显著低于其它三组(P<0.05),红细胞膜GSHPx活性为(367.17±129.86)Umgprot,明显高于其它三组(P<0.05);与对照、VE2、VE3组相比,VE1组淋巴细胞转化率分别提高了261.86%、199.23%、412.97%(P<0.05),10μmolLH2O2诱导的DNA氧化损伤程度显著降低(P<0.05);VE1组红细胞膜P、η值明显低于其它三组(P<0.05),即该组膜流动性显著提高。结论本实验揭示VE能明显改善红细胞膜流动性、提高淋巴细胞DNA抗氧化能力及增殖活性的有效补充剂量为50IUkgbw·d;补充剂量过大时未观察到类似作用,甚至显示细胞功能下降。     

孕晚期妇女贫血对妊娠结局的影响及贫血因素分析

目的:了解孕妇的贫血患病现状及其影响因素,探讨贫血对妊娠结局的影响。方法:对5308名孕产妇的年龄、文化程度、居住地、血红蛋白(Hb)及妊娠结局进行回顾性调查分析。结果:孕晚期妇女的贫血患病率为59.5%。贫血组的新生儿平均体重明显降低(P<0.01)。贫血组与非贫血组的LBW发生率无明显差异,但中度贫血组LBW发生率明显高于非贫血组。贫血组手术性分娩率明显高于非贫血组。孕妇的贫血率为农村高于城市;不同文化程度组的贫血患病率明显不同。结论:我国孕晚期妇女有近60%患有贫血,与不良妊娠结局有关;居住地、教育水平对孕妇的贫血患病率有影响。     

The multiple vitamin status of Chinese pregnant women with anemia and nonanemia in the last trimester

Iron-deficiency or anemia in pregnancy is a major public health problem in China. This cross-sectional study was carried out to observe the association between iron status and multiple vitamin levels of Chinese pregnant women in the third trimester. We measured iron, ascorbic acid, retinol, folate and vitamin B12 in serum, and riboflavin in urine specimens of 1,163 pregnant women in four sites throughout rural and city areas in China. Based on hemoglobin concentrations (Hb), the subjects were divided into an anemia group with Hb < 110 g/L or Hb < or = 100 g/L as severe anemia group, and nonanemia group with Hb > or = 110 g/L. Results showed that 41.58% of the population with serum iron < 700 microg/L and 51.04% of the population with ferritin < 12 microg/L in the anemia group, percentages that were much higher than those in the nonanemia group. Relationships between five vitamins and hemoglobin concentrations of all subjects were observed. There was a lower level of serum ascorbic acid (291.05 microg/dL) in the Hb < or = 100 g/L group than in the Hb > or = 120 g/L group (487.79 microg/dL) (p < 0.001). Serum levels of vitamin B12 and folate were 445.67 pg/mL and 5.94 ng/mL in the Hb < or = 100 g/L group, whose levels were much lower than the levels of 502.01 pg/mL (p < 0.012) and 8.07 ng/mL (p < 0.010) respectively in the Hb > or = 120 g/L group. Further, cross-sectional analysis showed positive correlations between abnormal hematological results and prevalences of vitamin deficiencies. The subjects with iron-deficiency anemia had much higher rates of vitamin C, folate and vitamin B12 deficiencies than those in the nonanemic subjects, and especially in the deficient rates of ascorbic acid and folate in the anemia (Hb < 110 g/L) group, which reached 64.04% and 22.70% respectively. Moreover, we observed that the decreasing trends of hemoglobin concentrations were accompanied by the decreases of serum levels of vitamin A, ascorbic acid, folate and vitamin B12. In conclusion, multiple vitamin deficiencies, especially ascorbic acid, retinol and folic acid, may be associated with anemia or iron deficiency in pregnant women in the last trimester. The study suggested that anemic pregnant women in China should be supplemented with iron and multiple vitamins simultaneously.