每周补充维生素A及每周补铁对学龄前儿童贫血的干预试验

【目的】　了解每周补充维生素A及每周补铁对改善学龄前儿童铁和维生素A营养状况的效果。　【方法】　将筛选出的铁和 /或维生素A缺乏儿童随机分成三组 ,每周分别给予 5万IU维生素A胶丸、60mg元素铁、10mg维生素B1,补充 4周后观察Hb、血清VA、铁蛋白、运铁蛋白受体的变化情况。　【结果】　干预前后 ,补铁组、补维生素A组以及补维生素B1组Hb值分别上升 8.8g/L ,10 .8g/L ,7.2 g/L(P <0 .0 0 1) ;补维生素A组和补维生素B1组血清VA分别上升 0 .13 7μmol/L ,0 .10 3 μmol/L(P <0 .0 0 1) ,而补铁组血清VA补充前后差异无显著性。各组铁蛋白在补充后显著性降低 ,而运铁蛋白受体显著升高。　【结论】　①由幼儿园教师监督实施每周补铁是行之有效的。②维生素A缺乏会影响铁向组织的转运和造血过程。③维生素A和铁缺乏同时存在地区 ,每周补维生素A与每周补铁在改善贫血上效果一致。     

补充维生素A与铁对改善学龄前儿童贫血和免疫功能的影响

目的为观察学龄前儿童亚临床维生素A(VA)缺乏状态缺铁时,机体免疫功能的变化以及VA与铁同时补充对改善儿童铁营养状况和免疫功能的影响.方法检测北京农村270名3～7岁儿童血清VA含量和血红蛋白(Hb)、血清铁(SI)、运铁蛋白饱和度(TS)及血清铁蛋白(SF)后,将其分为正常、低 VA、低铁和低VA低铁4组,每组选40人,检测血清免疫球蛋白IgA、IgG、IgM 与白细胞介素-2(IL-2).然后将低VA低铁组儿童随机分为补铁组 (每日口服相当于30 mg元素铁的硫酸亚铁,连续8周)和补VA+铁组(口服VA胶丸12 500 IU /次,2次/周,连续8周;口服铁量同补铁组,连续8周),分别进行干预.干预后重复检测血清VA、血液铁生化指标和以上免疫指标,进行两组间比较,并与干预前比较. 结果低VA低铁组儿童血清IgM为(1 260±310) mg/L显著高于正常组的(1 0 7 0±170) mg/L.对其实施VA+铁联合干预后,血清TS为(26.5±8.6)%,明显高于补铁前的(16.2±1.6)%和单纯补铁组的(22.3±3.8)%;IL-2在VA与铁同时补充后为(2 78.9±117.7) ng/L,显著高于补充前的(161.6±90.3) ng/L和单纯补铁组的(189 .5 ±89.3)ng/L的水平;其他铁生化指标和免疫指标无明显变化.结论对存在亚临床VA缺乏状态的缺铁儿童实施一定剂量的VA+铁联合干预,对改善机体铁营养状况和免疫功能有明显作用.     

妊娠妇女补充核黄素、VA对缺铁性贫血影响

目的 探讨补充核黄素、维生素A(VA)对妊娠妇女缺铁性贫血的影响.方法 将贫血孕妇分为补铁组、补铁 核黄素组、补铁 VA组、补铁 核黄素 VA组.补充上述营养素60 d,观察补充前后血红蛋白、血清铁蛋白、血清转铁蛋白受体的变化情况.结果 单独补铁、补铁 核黄素、补铁 VA、补铁 核黄素 VA均能显著提高妊娠妇女血红蛋白水平;补铁 VA组的血清铁蛋白明显高于补铁组(P<0.05);补铁 核黄素 VA组的血清铁蛋白明显高于补铁组、补铁 核黄素组、补铁 VA组(P<0.05),血清转铁蛋白受体显著低于补铁组、补铁 核黄素组、补铁 VA组(P<0.05).结论 单独补铁、补铁 核黄素、补铁 VA对改善缺铁性贫血均有明显效果,但铁、核黄素、VA等3种营养素同时补充,效果最好.     

儿少卫生

042 8 0 6　学龄儿童维生素A营养状况及其与铁的相关性研究 /林晓明…∥卫生研究 2 0 0 3 ,3 2 (1 ) 1 3～ 1 6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 3 0 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…     

间隔补铁对防治孕妇缺铁性贫血效果的评价

目的 :　研究间隔补铁对孕妇缺铁性贫血 (IDA)的防治效果。方法 :　将 1 91名孕中期妇女随机分为对照组、每周补铁组和每日补铁组 ,连续补铁 1 2 w,追踪观察两种补铁方案对孕妇缺铁及缺铁性贫血的防治效果。分别于实验前后测定血红蛋白 (Hb)、全血红细胞压积 (PCV)、血清铁 (SI)、血清铁蛋白 (SF)、红细胞游离原卟啉 (FEP) ,并观察副作用发生情况。结果 :　 1 .两个补铁组实验前后比较 ,主要铁营养指标均有明显改善 (P<0 .0 5 ) ,贫血患病率及铁缺乏率明显降低 (P<0 .0 0 1 ) ;而对照组孕中、晚期妇女的五项铁营养指标均显示 ,铁营养状况随孕期增加而明显下降 ,贫血患病率及铁缺乏率明显上升 ;2 .实验结束时 ,每周补铁组与每日补铁组间血液学反应无显著性差异。结论 :　每周补铁组在防治孕妇 IDA以及改善体内铁营养状况方面取得了与每日补铁组相似的临床效果 ,且节约了铁剂 ,降低了胃肠道副作用发生率 ,更易于被孕妇接受。     

补充铁和锌可显示墨西哥学龄前儿童维生素A状态

同时缺乏多种微量营养素是世界许多区域都存在的公共卫生问题。有人研究了锌缺乏与维生素 A代谢之间的相互作用 ,但尚无铁缺乏与维生素 A作用效果的纵向研究。本研究调查了补充铁、锌或两者对于维生素 A的效果 ,以及它们的代谢与蛋白视黄醇封闭蛋白 (protein retinol bindingprotein,RBP)及 transthyretin之间的关系。该研究为纵向、双盲、并应用安慰剂的试验 ,2 1 9名 1 8个月～ 3 6个月的墨西哥城郊儿童被随机分为补锌组 (2 0 mg/ d) ,补铁组 (2 0 mg/ d) ,补锌、铁组 (分别为 2 0 mg/d) ,或安慰剂组。与安慰剂对比 ,6月后所有治疗组血…     

补充维生素A对集体学龄前儿童血红蛋白的影响

【目的】　为探讨血清维生素 (VA)浓度对儿童血红蛋白的影响。　【方法】　对集体学龄前贫血儿童投维生素A每日 2 0 0 0IU ,观察治疗前后血红蛋白、血清铁、血清VA浓度的变化。　【结果】　亚临床状态VA缺乏占 31.6 % ,可疑缺乏占 5 8% ,仅 10 .4 %的儿童血清VA浓度正常 ;贫血组儿童血清VA量明显低于非贫血组 (P <0 .0 1)。给贫血组儿童投VA 2 0 0 0U/d ,3个月后 ,血红蛋白、血清铁、血清VA浓度明显提高 (P <0 .0 1) ,对照组无明显改变。　【结论】　亚临床状态VA缺乏在儿童中已是很重要的营养问题 ,并与贫血有一定关系 ,补充维生素A对儿童血红蛋白、血清铁、血清VA浓度有一定的影响     

维生素A缺乏对雌性大鼠生长发育及胚胎影响

目的建立维生素A（VA）完全及边缘缺乏的雌性大鼠模型,观察维生素A缺乏（VAD）对雌性大鼠及胚胎的影响。方法将初断乳SD雌性大鼠60只,随机分为VA缺乏组（AD）、VA边缘缺乏组（AM）、正常对照组（AN）,喂饲VA含量不同的饲料,耗竭性喂养后交配。将交配后的雌鼠在各组内随机分为VA缺乏组（A）、VA缺乏妊娠0d补充组（B）、VA边缘缺乏组（C）、VA边缘缺乏妊娠0d补充组（D）。B、D组于妊娠第0d喂饲补充饲料。于妊娠第19.5d将所有孕鼠处死并观察胚胎发育情况。结果发生AD组雌鼠出现明显的生长发育抑制。A组胚胎全为吸收胎,C组胚胎生长发育明显低于AN及B、C组,而畸胎死胎出现率明显高于AN及B、C组。结论VAD可明显影响雌性大鼠及其胚胎的生长发育,孕期补充VA可有效降低VAD对胚胎的发育毒性。     

维生素A缺乏对大鼠红细胞膜流动性的影响

目的　探讨维生素 A缺乏对大鼠红细胞膜流动性的影响。　方法　采用断乳期 2 1～ 2 3d Wistar大鼠 ,体重35～ 4 5 g,雌、雄各半 ,随机分为正常组及 VA缺乏组 ,分别饲喂正常饲料及无 VA的饲料 ,喂养 90 d后 ,腹主动脉取血 ,测定血清 VA含量 ,采用荧光偏振法 ,以 DPH为探针 ,测定红细胞膜流动性。　结果　正常组的雄、雌大鼠血清 VA水平为(0 .89± 0 .0 4 ) umol/ L ,而 VA缺乏组雄、雌性大鼠血清 VA水平分别降低到 (0 .14± 0 .0 5 ) umol/ L ,(0 .13± 0 .0 4 ) umol/ L ,两组比较 ,差异有极显著性 (t=4 0 .86 ,4 7.2 3,P<0 .0 1) ;维生素 A缺乏组雄、雌鼠红细胞膜的粘滞度高于正常组雄、雌鼠(t=3.2 0 ,2 .97,P<0 .0 1)　结论　维生素 A缺乏导致大鼠红细胞膜流动性降低     

健康成人补充维生素A对铁营养状况影响

目的探讨补充维生素A(VA)对健康成人铁营养的影响。方法选择120名健康志愿者,随机分为四组,正常膳食,进行6个月的不同VA剂量干预。抽取受试者干预前后空腹晨血并检测。结果干预后4组间血清VA浓度变化差异有统计学意义(P<0.05);干预前后各组受试者血液Hb浓度变化无统计学意义(P>0.05);干预后高剂量组血清铁营养指标变化差异有统计学意义(P<0.05),其他3组差异无统计学意义(P>0.05)。结论铁营养状况正常的成人,通过VA补充机体铁营养状况其他可得到提高。     

Effect of time of initiation and dose of prenatal iron and folic acid supplementation on iron and folate nutriture of Korean women during pregnancy

BACKGROUND: In Korea, it is customary to prescribe iron and folic acid supplements to pregnant women after the 20th wk of gestation; however, little evidence exists to support this practice. OBJECTIVE: The objective was to determine the effects of time of initiation and dose of prenatal iron and folic acid supplementation on the iron and folate nutriture of Korean women during pregnancy. DESIGN: A total of 131 pregnant women were placed into 1 of 5 experimental groups, either the control group or 1 of 4 supplemented groups. The supplemented groups varied by time of initiation, which was either during the first trimester or at week 20 of gestation, and by dose of iron and folic acid supplements provided, which consisted of either 30 mg Fe plus 175 microg folic acid or 60 mg Fe plus 350 microg folic acid. All supplemented groups continued supplementation until delivery. RESULTS: Improvements in iron and folate nutriture were highly dependent on when the supplement program was initiated, but both supplement doses were equally effective. In contrast, the influence of folic acid supplementation on maternal folate status was not as pronounced as was the influence of iron supplementation on iron status. CONCLUSION: In pregnant Korean women, initiating iron and folic acid supplementation earlier during pregnancy may prevent the deterioration of iron and folate nutriture more than does increasing supplement doses in later stages of pregnancy.     

Vitamin A and iron status are improved by vitamin A and iron supplementation in pregnant Indonesian women

In Indonesia, deficiencies of vitamin A and iron are of public health concern during pregnancy. We sought to determine the effects of vitamin A and iron supplementation on the vitamin A and iron status of pregnant Indonesian women. The women (n = 27) were randomly assigned to four groups. The modified relative dose response (MRDR) test for vitamin A status and hemoglobin, hematocrit and ferritin values were determined at baseline. Thereafter, daily supplements were administered: placebo [Pl] (n = 7), 8.4 micromol vitamin A [A] (n = 7), 1.07 mmol iron [Fe] (n = 5), and 8.4 micromol vitamin A plus 1.07 mmol iron [A + Fe] (n = 8). Post-treatment tests were performed after 8 wk. The MRDR value was reduced, i.e., vitamin A status improved, more markedly by the combination of vitamin A and iron than by either nutrient alone (P = 0.034). The decrease in the MRDR relative to baseline was significant in the A + Fe group (P = 0.008). Iron status was also significantly improved in these women (P < 0.05) with both iron and vitamin A supplementation. The mechanism of the enhancing effect of iron on the vitamin A-induced reduction in the MRDR is not known.     

Responsiveness of dark-adaptation threshold to vitamin A and beta-carotene supplementation in pregnant and lactating women in Nepal

BACKGROUND: Impaired dark adaptation occurs commonly in vitamin A deficiency. OBJECTIVE: We sought to examine the responsiveness of dark-adaptation threshold to vitamin A and beta-carotene supplementation in Nepali women. DESIGN: The dark-adapted pupillary response was tested in 298 pregnant women aged 15-45 y in a placebo-controlled trial of vitamin A and beta-carotene; 131 of these women were also tested at 3 mo postpartum. Results were compared with those for 100 nonpregnant US women of similar age. The amount of light required for pupillary constriction was recorded after bleaching and dark adaptation. RESULTS: Pregnant women receiving vitamin A had better dark-adaptation thresholds (-1.24 log cd/m(2)) than did those receiving placebo (-1.11 log cd/m(2); P: = 0. 03) or beta-carotene (-1.13 log cd/m(2); P: = 0.05) (t tests with Bonferroni correction). Dark-adaptation threshold was associated with serum retinol concentration in pregnant women receiving placebo (P: = 0.001) and in those receiving beta-carotene (P: = 0.003) but not in those receiving vitamin A. Among women receiving placebo, mean dark-adaptation thresholds were better during the first trimester (-1.23 log cd/m(2)) than during the second and third trimesters (-1.03 log cd/m(2); P: = 0.02, t test). The mean threshold of nonpregnant US women (-1.35 log cd/m(2)) was better than that of all 3 Nepali groups (P: < 0.001, t test, for all 3 groups). CONCLUSIONS: During pregnancy, pupillary dark adaptation was strongly associated with serum retinol concentration and improved significantly in response to vitamin A supplementation. This noninvasive testing technique is a valid indicator of population vitamin A status in women of reproductive age.     

Weekly supplementation with iron and vitamin A during pregnancy increases hemoglobin concentration but decreases serum ferritin concentration in Indonesian pregnant women

We investigated whether weekly iron supplementation was as effective as the national daily iron supplementation program in Indonesia in improving iron status at near term in pregnancy. In addition, we examined whether weekly vitamin A and iron supplementation was more efficacious than weekly supplementation with iron alone. One group of pregnant women (n = 122)was supplemented weekly with iron (120 mg Fe as FeSO4) and folic acid (500 microg); another group (n = 121) received the same amount of iron and folic acid plus vitamin A [4800 retinol equivalents (RE)]. A third ("daily") group (n = 123), participating in the national iron plus folic acid supplementation program, was also recruited. Data on subjects with complete biochemical data are reported (n = 190). At near term, hemoglobin concentrations increased, whereas serum ferritin concentrations decreased significantly in the weekly vitamin A and iron group, suggesting that vitamin A improved utilization of iron for hematopoiesis. Iron status in the weekly iron group was not different from that of the "daily" group. However, iron status decreased with daily supplementation if <50 iron tablets were ingested. Serum transferrin receptor concentrations increased in all groups (P < 0.01). Serum retinol concentrations were maintained in the weekly vitamin A and iron group, but decreased in the other two groups (P < 0.01). Thus, delivery of iron supplements on a weekly basis can be as effective as ona daily basis if compliance can be ensured. Addition of vitamin A to the supplement improved hemoglobin concentration.     

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.     

Zinc plus beta-carotene supplementation of pregnant women is superior to beta-carotene supplementation alone in improving vitamin A status in both mothers and infants

BACKGROUND: Deficiencies of vitamin A, iron, and zinc are prevalent in women and infants in developing countries. Supplementation during pregnancy can benefit mother and infant. OBJECTIVE: We examined whether supplementation during pregnancy with iron and folic acid plus beta-carotene or zinc or both improves the micronutrient status of mothers and infants postpartum. DESIGN: Pregnant women (n = 170) were supplemented daily only during pregnancy with beta-carotene (4.5 mg), zinc (30 mg), or both or placebo plus iron (30 mg) and folic acid (0.4 mg) in a randomized, double-blind, placebo-controlled trial. Micronutrient status was assessed 1 and 6 mo postpartum. RESULTS: Six months postpartum, plasma retinol concentrations were higher in the women who received zinc during pregnancy than in women who did not. Infants born to mothers supplemented with beta-carotene + zinc had higher plasma retinol concentrations, with the frequency of vitamin A deficiency reduced by >30% compared with the other 3 groups. Breast-milk beta-carotene concentrations were higher in all women supplemented with beta-carotene, but breast-milk retinol concentrations were higher only in women who received beta-carotene + zinc. Zinc concentrations did not differ among groups in mothers and infants. CONCLUSIONS: Zinc supplementation during pregnancy improved the vitamin A status of mothers and infants postpartum, which indicates a specific role of zinc in vitamin A metabolism. Addition of both beta-carotene and zinc to iron supplements during pregnancy could be effective in improving the vitamin A status of mothers and infants.     

Hematological effect of supplementing anemic children with vitamin A alone and in combination with iron

Ninety-nine anemic children aged 1-8 y were divided into four groups. Each group was supplemented for 2 mo with vitamin A, iron, vitamin A plus Fe, or a placebo. Clinical, hematological, and Fe biochemical evaluations were performed at the beginning and end of the study. Vitamin A supplementation produced significant elevations in the serum levels of retinol, blood hemoglobin, hematocrit, erythrocytes, serum Fe, and percent transferrin saturation (%TS) and had no effect on total Fe binding capacity (TIBC) or serum ferritin. Fe supplementation did not affect serum retinol. However, it improved hematological and Fe nutrition indicators, including TIBC and serum ferritin. The simultaneous administration of vitamin A and Fe resulted in a better response of serum Fe and %TS than when the supplement consisted only of vitamin A or Fe alone. Vitamin A benefits hematological condition and Fe metabolism.     

Influence of prenatal iron and zinc supplements on supplemental iron absorption, red blood cell iron incorporation, and iron status in pregnant Peruvian women

BACKGROUND: It is estimated that 60% of pregnant women worldwide are anemic. OBJECTIVE: We aimed to examine the influence of iron status on iron absorption during pregnancy by measuring supplemental iron absorption, red blood cell iron incorporation, and iron status in pregnant women. DESIGN: Subjects were 45 pregnant Peruvian women (33+/-1 wk gestation), of whom 28 received daily prenatal supplements containing 60 mg Fe and 250 microg folate without (Fe group, n = 14) or with (Fe+Zn group, n = 14) 15 mg Zn, which were were consumed from week 10 to 24 of gestation until delivery. The remaining 17 women (control) received no prenatal supplementation. Iron status indicators and isotopes were measured in maternal blood collected 2 wk postdosing with oral (57Fe) and intravenous (58Fe) stable iron isotopes. RESULTS: Maternal serum ferritin and folate concentrations were significantly influenced by supplementation (P < 0.05). Serum iron was also significantly higher in the Fe than in the Fe+Zn (P < 0.03) or control (P < 0.001) groups. However, the supplemented groups had significantly lower serum zinc concentrations than the control group (8.4+/-2.3 and 10.9+/-1.8 micromol/L, respectively, P < 0.01). Although percentage iron absorption was inversely related to maternal serum ferritin concentrations (P = 0.036), this effect was limited and percentage iron absorption did not differ significantly between groups. CONCLUSIONS: Because absorption of nonheme iron was not substantially greater in pregnant women with depleted iron reserves, prenatal iron supplementation is important for meeting iron requirements during pregnancy.     

Vitamin A and iron supplementation of Indonesian pregnant women benefits vitamin A status of their infants.

Many Indonesian infants have an inadequate nutritional status, which may be due in part to inadequate maternal nutrition during pregnancy. This study was designed to investigate whether infant nutritional status could be improved by maternal vitamin A and Fe supplementation during gestation. Mothers of these infants from five villages had been randomly assigned on an individual basis, supervised and double-blind, to receive supplementation once weekly from approximately 18 weeks of pregnancy until delivery. Supplementation comprised 120 mg Fe and 500 microg folic acid with or without 4800 retinol equivalent vitamin A. Mothers of infants from four other villages who participated in the national Fe and folic acid supplementation programme were also recruited; intake of tablets was not supervised. Anthropometric and biochemical parameters of infants and their mothers were assessed approximately 4 months after delivery. Infants of mothers supplemented with vitamin A plus Fe had higher serum retinol concentrations than infants of mothers supplemented with Fe alone. However, the proportion of infants with serum retinol concentrations <0.70 micromol/l was >70 % in all groups. Maternal and infant serum retinol concentrations were correlated. Fe status, weight and length of infants were similar in all groups. Fe status of girls was better than that of boys, but boys were heavier and longer. We conclude that supplementation with vitamin A in conjunction with Fe supplementation of women during pregnancy benefits vitamin A status of their infants. However, considering the large proportion of infants with marginal serum retinol concentrations, it may still be necessary to increase their vitamin A intake.