乙二胺四乙酸铁钠中铁在人体吸收率的研究

目的 :　研究在中国典型膳食条件下乙二胺四乙酸铁钠 ( Na Fe EDTA)中铁在人体的吸收率。方法 :　采用铁稳定性同位素54 Fe和58Fe分别标记 Fe SO4 和 Na Fe EDTA并以稀土元素镝 ( Dy)作为排泄物回收标记物。自愿受试者为 1 8～ 2 2岁健康女性。采用我国典型城镇成年女性膳食模式。两种铁剂和 Dy以酱油为食物载体一同分两天 6次经口给入。实验期间每日留取受试者膳食样品并收集受试者在实验期的粪便。采用原子吸收 ( AAS)和等离子体质谱 ( ICP- MS)分别检测膳食和粪便中总铁含量和铁同位素比例 ,对两种铁剂中铁的吸收率进行比较。结果 :　 Fe SO4 的铁平均吸收率为 4.73% ,而 Na Fe EDTA为 1 0 .51 % ,两者差异为极显著 ( P<0 .0 1 )。结论 :　Na Fe EDTA中铁的吸收率优于 Fe SO4 。     

同位素示踪法测定儿童铁的吸收率

目的:研究农村代表性膳食条件下儿童铁的吸收率。方法:采用天然低丰度稳定性同位素Fe标记FeSO4,以稀土元素镝(Dy)作为排泄物回收标记物。自愿受试者为4～6岁身体健康的农57村儿童。采用山东农村代表性膳食模式。同位素标记铁与Dy以饼干为载体分两天三餐前经口给予。实验期间每日留取受试者膳食样品并收集受试者在实验期的粪便,采用原子吸收(AAS)和热电离质谱(TIMS)分别检测膳食和粪便中总铁含量与Fe/56Fe比值,计算铁的吸收率。同时对脂肪、瘦肉、57蛋白、植酸、纤维素和VC的日摄入量进行测定,并将结果与我国每日营养推荐膳食供给量(DRI)比较。结果:铁的吸收率(%)为6.06±2.24,远低于1988年我国修订推荐RDA所参考国外的10%,铁的平均日摄入量为10.29mg,占DRI的102.9%,其中血红素铁平均日摄入量占总铁日摄入量的17.49%,基本达到推荐量。蛋白质和抗坏血酸的日摄入量仅占DRI的56.73%和29.60%远低于推荐量。脂肪、植酸和膳食纤维的摄入量较高。结论:按目前山东农村的膳食模式,儿童铁日摄入量已达推荐量,但吸收率偏低,因而铁摄入量仍不足。蛋白质和抗坏血酸的日摄入量较低。     

稳定性同位素评价藏族青年男子膳食铁的吸收率

目的用铁的稳定性同位素示踪剂评价藏族青年男子膳食铁的吸收率,为改善该人群膳食铁吸收的提供参考数据。方法于现场进行人体代谢试验,受试者口服稳定性同位素示踪铁剂(浓集57Fe的FeSO4)及稀土元素镝,粪便监测法收集示踪剂排出粪样;用感耦等离子体质谱仪测定粪样57Fe56Fe的比值,分析评价该人群膳食铁的吸收率。结果口服同位素评价藏族青年男子膳食铁的吸收率为13.4%±6.4%;每日示踪剂铁和镝排出呈良好相关性。结论稀土元素镝与未吸收的示踪剂铁在消化道有一致的排出过程,前者的回收率能很好反映粪样收集情况;藏族成年男子膳食铁的吸收较好。     

乙二胺四乙酸铁钠强化酱油改善贫血效果观察

本研究比较了NaFeEDTA强化酱油、硫酸亚铁 (FeSO4)强化酱油对IDA改善效果。将 30 0名IDA学生分为对照组、NaFeEDTA强化酱油组Fe 5mg (人·日 )、FeSO4强化酱油组Fe5mg (人·日 ) ,比较新型铁强化剂 (NaFeEDTA)与传统铁剂 (FeSO4)对缺铁性贫血的改善作用。结果表明 ,对照组各项检验指标干预前后没有显著差异。其它各试验组呈现出较为一致的变化 ,表现为血红蛋白、血清铁、血清铁蛋白含量的显著性增加和原卟啉、总铁结合力、转铁蛋白的显著性下降。试验结果提示 ,乙二胺四乙酸铁钠与传统铁剂 (硫酸盐铁 )强化酱油均有改善学生贫血的作用 ,并且NaFeEDTA组的贫血改善率和Hb恢复水平优于FeSO4组。     

稳定同位素示踪法测定青春前期儿童铁吸收率

目的利用稳定同位素示踪技术评价青春前期儿童铁吸收率。方法利用人工富集57Fe标记并制备为57FeSO4口服剂,在常规膳食模式下,早、晚餐前经口给予57名受试者,共5天。收集规定时间内受试者全部粪便,前处理后分别经原子吸收分光光度计(AAS)和多接受等离子质谱仪(MC-ICP-MS)测定铁的含量和丰度,以评价青春前期儿童铁的吸收率情况。结果男、女性儿童铁表观吸收率分别为(26.71±2.94)%和(29.76±2.20)%,校正回收率分别为(27.45±2.83)%和(31.01±2.48)%,男性均显著低于女性儿童(P0.05)。结论空腹口服稳定同位素示踪剂条件下,青春期儿童铁吸收率均较高,但男性吸收率略低于女性。     

乙二胺四乙酸铁钠对酱油感官和理化性质及稳定性的影响

将NaFeEDTA、NaFeCT、FeSO4分别添加于低盐固态和高盐稀态工艺生产的二种品牌酱油中 ,其中铁含量分别为 0、0 5、1 0、2 0、4 0和 8 0mg ml。测定酱油的口感指数、沉淀指数和A650 、pH、密度、氨基态氮以及可溶性固形物含量等理化指标 ,结果表明 ,铁的含量越高 ,酱油的口感和沉淀影响越严重。三种铁剂对两种酱油的pH值、密度、氨基态氮和固形物含量无明显影响。但NaFeEDTA对酱油感官的影响最小 ,而FeSO4的影响最大。由于NaFeEDTA在低浓度时 ,即在强化食品的允许强化剂量范围内 ,对酱油品质几乎没有影响 ,所以认为NaFeEDTA是较为适宜酱油强化的铁强化剂。 12个月后测定NaFeEDTA强化酱油的各项品质指标 ,酱油品质没有发生变化。表明NaFeEDTA强化酱油在保质期内稳定。     

青春前期女童口服铁剂吸收利用的动力学研究

目的探讨青春前期女性儿童铁的利用率情况。方法在常规膳食模式下,以57Fe为示踪剂,27名10~12岁女性儿童为受试对象,分别在口服示踪剂前、14天后和28天后采集静脉血分离红细胞。样品经消化后分别测定其铁含量及同位素丰度,计算并分析受试者57Fe在红细胞中掺入情况。结果 14天和28天红细胞内57Fe与摄入总量比值分别为(19.84±0.53)%和(18.75±0.40)%(P0.05),红细胞内57Fe与全血中57Fe量比值分别为(93.49±2.27)%和(88.73±0.43)%,14天红细胞掺入率显著高于28天时(P0.05)。结论以单标稳定同位素示踪评价青春前期女性儿童红细胞掺入率,可反映受试者体内铁的利用情况。青春前期女性儿童铁的利用率普遍较高,给予示踪剂后14天可作为红细胞掺入率研究的切入点。     

山东农村典型膳食儿童人体锌吸收率研究

目的研究山东农村典型膳食锌(Zn)在农村儿童人体吸收率及Zn吸收相关营养素的日摄入量。方法受试者为4～6岁身体健康的农村儿童。标记稳定性同位素67Zn3.0mg,晚餐前一次经口给予,采用原子吸收法(AAS)和热电离质谱(TIMS)分别检测膳食和粪便中总锌含量与67Zn/68Zn比值,计算锌的吸收率,并对膳食铁、钙、脂肪、蛋白、植酸、纤维素和维生素C(VC)含量测定,将结果与我国儿童日推荐膳食营养素摄入量(RNIs)比较。结果锌的吸收率为(12.94±3.32)%,锌的平均日摄入量为11.16mg,占RNI的96.7%,蛋白质和抗坏血酸的日摄入量分别为31.2g与13.3mg,占RNI的62.4%和19.0%。结论在目前山东农村的膳食模式下,儿童体内锌的吸收率偏低,蛋白质和抗坏血酸的日摄入量不足。     

湖南、湖北等省成年人膳食锌吸收率分析

目的 评价我国湖南、湖北等省成年人膳食结构中Zn的吸收率,为我国不同人群、不同膳食结构的Zn吸收率研究提供参考资料.方法 采用67ZnSO4锌稳定性同位素示踪法,以稀土元素镱(Yb)为粪便回收标记物,进行现场人体代谢实验.受试者为健康成年男子和育龄妇女各10名,一次性口服4.00 mg 67ZnSO4和1.00mg YbCl3,粪便监测法收集排出粪样;电感耦合等离子体质谱仪(ICP-MS)测定粪样中67Zn/66Zn比值,原子吸收火焰分光光度法(AAS)测定粪样总Zn,计算膳食Zn吸收率.结果 在不同膳食结构下,成年男子Zn表观吸收率为28.4%,真吸收率为30.3%;育龄妇女Zn表观吸收率为26.8%,真吸收率为30.9%.结果 湖南、湖北等省份膳食结构中zn的吸收率高于我国现行Zn的膳食营养参考摄入量(DRIs)(25%的估计值).     

NaFeEDTA强化酱油对铁缺乏的防治效果——人群干预试验

在过去研究人体铁吸收率和对贫血儿童的治疗试验的基础上 ,观察NaFeEDTA强化酱油在自然高危人群中纠正铁缺乏的效果及可接受性。在贵州省毕节市海子街镇用双盲安慰剂对照法 ,在 14 0 0 0名 3岁以上人群中进行为期 18个月的NaFeEDTA强化酱油 (Fe 2 96mg铁 L)干预试验。观察指标包括 :血红蛋白、红细胞压积、血浆铁蛋白和维生素A、膳食、体格测量、智力发育和身体耐力。干预组平均每人每天消费 16 5ml酱油 ,其中含 4 9mg来自NaFeEDTA的铁。与对照人群相比 ,干预人群中各年龄 -性别组的血红蛋白水平明显升高、贫血率明显下降、血浆铁蛋白明显升高 ;3～ 6岁儿童身高和体重明显改善。而同时 ,两组食物消费与试验前无明显差别。NaFeEDTA强化酱油对于纠正铁缺乏、降低贫血率以及改善儿童生长发育有明显效果。同时 ,试验参加者一致反映铁强化酱油的感官性状良好 ,可接受性良好。     

Iron absorption from fish sauce and soy sauce fortified with sodium iron EDTA

BACKGROUND: Fish sauce and soy sauce have been suggested as food vehicles for iron fortification in Asia. NaFeEDTA is a potentially useful fortificant because it can be added to these condiments without causing precipitation during storage. OBJECTIVES: The objectives were to evaluate iron absorption from NaFeEDTA-fortified fish sauce and soy sauce against a reference fortificant (FeSO(4)), to compare iron absorption from NaFeEDTA-fortified fish sauce and soy sauce, and to evaluate the influence of fish sauce and soy sauce per se on iron absorption. DESIGN: Five separate iron-absorption studies were made in adult women (10 women per study). Iron absorption was measured on the basis of erythrocyte incorporation of (57)Fe or (58)Fe 14 d after the intake of labeled meals of rice or rice and vegetables. Fish sauce or soy sauce (10 g) fortified with 5 mg Fe as NaFeEDTA or FeSO(4) was fed with selected meals. The results are presented as geometric means. RESULTS: Iron absorption from NaFeEDTA- and FeSO(4)-fortified fish sauce (3.3% and 3.1%, respectively) and soy sauce (6.1% and 5.6%, respectively) was not significantly different. No significant difference was observed when NaFeEDTA-fortified fish sauce and soy sauce were compared directly (6.7% and 7.9%, respectively). Soy sauce inhibited iron absorption from rice-based meals (8.5% without and 6.0% with soy sauce; P < 0.02), whereas fish sauce did not affect iron absorption significantly. CONCLUSION: The relatively high iron absorption from NaFeEDTA-fortified fish sauce and soy sauce and the acceptable organoleptic properties of NaFeEDTA indicate the potential usefulness of this iron fortificant in fish sauce and soy sauce fortification programs.     

Sodium iron NaFeEDTA as an iron fortification compound in Central America. Absorption studies.

Studies were performed in seven children and 98 adults to compare the proportion of iron absorbed when administered as ferric sulfate (Fe2(SO4)3), NaFeEDTA, hemoglobin (Hb), and ferrous ascorbate. Studies in children (mostly iron deficient) showed that when the compounds were given with a milk-rice-sugar formula totalling 5 mg Fe, iron from hemoglobin was absorbed best, followed by NaFeEDTA and by Fe2(SO4)3 (mean percent absorption +/-SD = 34.5 +/- 1.5, 8.6 +/- 1.9 and 3.3 +/- 1.5, respectively). Studies in normal or iron deficient adults also demonstrated a better absorption of iron from NaFeEDTA than from Fe2(SO4)3 whether these compounds were given in an aqueous solution (5 mg Fe) or with a standard meal consisting of beans, tortillas, bread, and coffee providing also a total of 5 mg Fe. Hb iron under the same conditions was absorbed in the same proportion to the reference iron ascorbate, always being higher than iron absorbed from the other compounds. Fe2(SO4)3 and NaFeEDTA mixed in the same meal were absorbed in the same proportion as when NaFeEDTA alone was added to the meal and 2 to 3 times better than when Fe2(SO4)3 alone was added to the meal. Addition of desferrioxamine depressed iron absorption from Fe2(SO4)3 and NaFeEDTA, the latter being less affected. Addition of ascorbic acid increased absorption from both. When the compounds were added to the meal to provide 50 mg of iron, percent absorption was depressed in relation to the smaller iron dose in the case of Fe2(SO4)3 and Hb but remained unaltered in the case of NaFeEDTA. Addition of 45 mg Fe as Fe2(SO4)3 or NaFeEDTA to 0.4 mg Fe from the Hb in the meal did not change Hb iron absorption. Addition of 45 mg Fe as Hb or NaFeEDTA to 0.4 mg Fe from Fe2(SO4)3 in the meal enhanced iron absorption from the latter in the same proportions. Addition of 45 mg Fe as Fe2(SO4)3 and Hb to 0.4 mg Fe as NaFeEDTA in the meal respectively depressed and enhanced iron absorption from NaFeEDTA. These studies indicate that NaFeEDTA, Fe2(SO4)3 and nonheme food iron from a common pool different from the heme pool but which is changed in its characteristics by the presence of NaFeEDTA, resulting in a better absorption of iron.     

Iron absorption from a breakfast cereal: effects of EDTA compounds and ascorbic acid

Sodium iron ethylenediaminetetracetic acid (NaFeEDTA) has been recommended for food fortification programmes to improve iron status but its performance in commercial products has not been evaluated. The effect of EDTA on iron absorption from fortified cornflakes, given as part of a typical Western breakfast, was determined in a double-blind randomised study with 20 non-anaemic female volunteers, using experimentally prepared iron compounds, enriched with 58Fe, and faecal monitoring. Five meals were compared: hydrogen reduced iron, hydrogen reduced iron plus Na2EDTA (molar ratio EDTA:Fe 1:2), hydrogen reduced iron plus NaFe(III)EDTA at two different molar ratios (EDTA:total Fe 1:3 and 1:2), and hydrogen reduced iron plus 15 mg ascorbic acid (ascorbic acid:Fe 1.3:1). The iron and EDTA compounds were accurately weighed into gelatine capsules and taken with unfortified cornflakes, semi-skimmed milk and tea on two consecutive days; the iron dose per meal was 3.75 mg. Iron absorption from all five test meals was measured in each volunteer with a minimum wash-out period of 2 weeks between tests. Geometric mean iron absorption (%) from the 5 tests was 14.1, 17.6, 20.6, 24.4 and 17.5 respectively (equivalent to 0.5-0.9 mg absorbed iron). There was a significantly higher iron absorption from the mixture of reduced iron and NaFe(III)EDTA (EDTA:Fe 1:2) than from reduced iron alone (p = 0.014). It is not known whether the higher absorption was from reduced iron or NaFeEDTA or both. Absorption was not increased significantly with NaFe(III)EDTA (EDTA:Fe 1:3), Na2EDTA (EDTA:Fe 1:2) or ascorbic acid (15 mg).     

Iron absorption from NaFeEDTA is downregulated in iron-loaded rats

NaFeEDTA is a promising fortificant for use in plant foods, because it is less susceptible to iron absorption inhibitors and has fewer undesirable impacts on sensory quality than ferrous sulfate. However, the hypothesis that iron absorption from NaFeEDTA is effectively downregulated in iron-overload conditions has not been thoroughly tested. Therefore, the objective of this study was to compare downregulation of iron absorption from ferrous sulfate and NaFeEDTA in intact iron-loaded rats. Male Sprague-Dawley rats were fed diets containing either ferrous sulfate (35 mg Fe per 1 kg diet) or elemental iron (30,000 mg Fe per 1 kg diet) for 29 d to achieve basal or iron-loaded status. While body weights and hemoglobin concentrations were the same for basal and iron-loaded rats, nonheme-iron concentrations in liver, spleen, and kidney were all significantly higher in iron-loaded rats, indicating elevated iron status. Percentage of iron absorption from (59)Fe-labeled ferrous sulfate and NaFeEDTA, determined from whole-body retention of (59)Fe activity, was 64.7 and 49.4% in basal rats but decreased to 12.8 and 10.2% in iron-loaded rats, respectively. The reductions in percentage of iron absorption from both iron sources in rats as a result of iron loading were comparable (about -80% for both iron sources). Our results suggest that iron absorption from NaFeEDTA and ferrous sulfate is downregulated to a similar extent in iron-loaded rats. Hence, NaFeEDTA is no more likely than ferrous sulfate to exacerbate iron overload in subjects with adequate body iron stores.     

Sodium iron EDTA [NaFe(III)EDTA] as a food fortificant: erythrocyte incorporation of iron and apparent absorption of zinc, copper, calcium, and magnesium from a complementary food based on wheat and soy in healthy infants

BACKGROUND: Phytic acid is a strong inhibitor of iron absorption from fortified foods. In adults, this inhibitory effect can be overcome by adding ascorbic acid with the iron fortificant or by using a "protected" iron compound such as NaFeEDTA. In addition, the use of NaFeEDTA as an iron fortificant has been reported to increase zinc absorption in adult women. No information is available on iron bioavailability from NaFeEDTA or the influence of NaFeEDTA on minerals and trace elements in infants. OBJECTIVE: We aimed to compare iron bioavailability from a complementary food based on wheat and soy fortified with either NaFeEDTA or ferrous sulfate plus ascorbic acid. The apparent absorption of zinc, copper, calcium, and magnesium was evaluated in parallel. DESIGN: Stable-isotope techniques were used in a crossover design to evaluate erythrocyte incorporation of iron 14 d after administration of labeled test meals and the apparent absorption of zinc, copper, calcium, and magnesium on the basis of fecal monitoring in 11 infants. RESULTS: Geometric mean erythrocyte incorporation of iron was 3.7% (NaFeEDTA) and 4.9% (ferrous sulfate plus ascorbic acid) (P = 0.08). No significant differences in the apparent absorption of zinc, copper, calcium, or magnesium were observed between test meals (n = 10). CONCLUSIONS: Iron bioavailability from a high-phytate, cereal-based complementary food fortified with either NaFeEDTA or ferrous sulfate plus ascorbic acid was not significantly different. NaFeEDTA did not influence the apparent absorption of zinc, copper, calcium, or magnesium. NaFeEDTA does not provide any nutritional benefit compared with the combination of a highly bioavailable iron compound and ascorbic acid.     

Serum iron curves can be used to estimate dietary iron bioavailability in humans

Erythrocyte incorporation of isotopic iron (Fe) is the standard method for assessing iron bioavailability, but the process is expensive, technically difficult, and gives no information on the kinetics of absorption. The main objective of this study was to validate serum Fe curves as measures of dietary iron absorption because previous work demonstrated that serum iron curves can be generated with iron doses as low as 5-20 mg and that up to 20 mg iron can be added to meals without affecting relative absorption. In 3 studies, groups (n = 10, 10, 21) of Fe-deficient, mildly anemic women consumed meals of varying calculated Fe bioavailability, with and without added ferric chloride (10 mg Fe). Blood samples were collected at baseline and every 30 min for 4 h after the meal. Serum Fe concentrations were measured. Areas under the serum Fe curves and peak concentrations were used in different models to estimate Fe absorption and uptake. In 21 subjects, (58)Fe-enriched ferric chloride was added to the meals, and blood was taken 2 wk later to calculate red cell isotope incorporation. The addition of 10 mg Fe to test meals produced measurable serum iron curves even when the meal Fe bioavailability was low. Serum Fe curves were highly reproducible and were affected as expected by food composition. Even the single measurement at the estimated time of peak iron concentration was correlated significantly with erythrocyte incorporation of (58)Fe (r = 0.72, P < 0.0001). Hence the extent and rate of absorption of nonheme iron from meals, rather than in individuals, can be investigated with such subjects without the need for isotopes.