藏族成年男子膳食中锌的吸收状况研究

目的了解藏族成年男子膳食中锌的吸收利用,为修订膳食营养素参考摄入量(DRIs)和改善锌的营养状况提供理论依据。方法在营养调查的基础上设计出代表性的3d食谱,选择13名18~19岁的藏族健康男子给予试验膳进行14d的代谢平衡实验,收集试验期受试者的膳食、饮水、粪便、尿液样品,采用火焰原子吸收光谱法测定各样品中锌的含量,计算锌的表观吸收率、表观利用率。结果锌的表观吸收率为24·15%,与现行的DRIs的制订依据估计值接近;表观利用率为7·61%。结论代表性膳食中锌的摄入量能满足受试者的需要量。     

藏族成年男子膳食中铁的吸收状况研究

目的：了解藏族成年男子膳食中铁的吸收利用，为修订膳食营养素参考摄入量(DRIs)和改善铁的营养状况提供理论依据。方法：选择15名藏族成年健康男子给予代表性试验膳进行14d代谢平衡实验，收集血液样品测定铁营养状况指标，采用火焰原子吸收光谱法测定受试者的膳食、饮水、粪便、尿液样品中铁的含量。结果：受试者的铁营养状况正常、稳定。铁摄入量为61．96mg／d，粪铁排出量为42．16mg／d，尿铁排出量为6．95mg／d；铁表观吸收率为32．02％；铁表观利用率为20．79％，高于现行的DRIs的制订依据。结论：代表性膳食中铁的摄入量可满足受试者的需要量。     

山东省农村育龄妇女代表性膳食下铁、锌、钙吸收率分析

目的:研究山东省农村育龄妇女代表性膳食下铁、锌、钙的吸收率,以及膳食因素对它们吸收利用的影响。方法:用代谢平衡法,使用原子吸收分光光度计(AAS)测定膳食与粪便的铁、锌、钙,计算铁、锌、钙的吸收率。同时测定影响铁、锌、钙吸收的因子:膳食脂肪、蛋白、植酸、纤维素和VitC的含量,计算日平均摄入量,将其结果与我国育龄妇女每日推荐膳食营养素摄入量(RNI)进行比较。结果:铁、锌、钙的吸收率分别为8·26%、21·48%、47·94%,铁的平均日摄入量为13·77mg,占RNI的68·85%,远低于推荐量,锌的平均日摄入量为15·43mg,占RNI的102·87%,高于推荐量,钙的平均日摄入量为409·38mg,占RNI的51·17%,远低于推荐量。蛋白质和VitC的日摄入量分别为65·70g与34·20mg,占RNI的82·12%~109·50%和34·20%,低于推荐量。脂肪、植酸和膳食纤维的摄入量较高。结论:在蛋白质和抗坏血酸的日摄入量较低,脂肪、植酸和膳食纤维的摄入量较高的条件下,铁吸收率较低,铁营养缺乏,锌营养尚可,钙摄入量显著低于RNI,显示钙摄入严重不足。     

代谢平衡法与粪便监测法评价藏族成年男子膳食锌吸收率的比较

目的:比较代谢平衡法(MB)和粪便监测法(FM)评价藏族成年男子膳食锌(Zn)吸收率。方法:进行14d人体现场代谢试验,受试者于D5晚一次性口服浓集67Zn的稳定性同位素示踪剂4.0mg及稀土元素镱(Yb)1.0mg,口服卡红标记、并收集D4~12的粪便和尿液样品,同时收集膳食、饮水样品;用感耦等离子体质谱仪测定粪样67Zn/68Zn的比值,并用原子吸收分光光度计分析所收集样品中的锌含量,比较用两种方法测定该人群膳食Zn吸收率的结果。结果:MB和FM评价藏族成年男子膳食Zn吸收率分别为(23.8±3.9)%、(21.4±4.3)%,二者的差异(配对t检验)和相关性(Pearson)均有统计学意义;未吸收的Zn示踪剂和Yb经胃肠道排出情况几乎一致,主要在口服后5d内排出。结论:14d代谢试验评价膳食Zn吸收率时,MB略高于FM,后者的试验期可依据Yb的排出情况缩短至4~5d。两种方法评价的结果都表明藏族成年男子膳食Zn吸收尚可。     

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).     

12～14岁男童体内强化去植酸豆粉中钙铁锌的吸收利用率研究

目的　为了解我国少年儿童对豆粉、去植酸豆粉和牛奶中钙、铁、锌的吸收利用率 ,通过普及饮用豆粉 ,改善我国居民蛋白质和矿物质的营养状况提供理论依据。方法　选择 57名 1 2～ 1 4岁男童 ,按年龄、身高、体重和血红蛋白含量匹配 ,分成 3组 ,分别给予强化豆粉、强化去植酸豆粉和强化牛奶 2 2 0ml,其中含钙 2 70mg、铁 4mg、锌 4mg。给予受试者用稳定性核素4 4Ca、58Fe和70 Zn标记的受试物 ,以亮蓝和镝标记粪便 ,收集粪便样品 ,测量强化去植酸豆粉、豆粉和强化牛奶中钙、铁、锌的吸收率 ;使用热离子化质谱法测定粪便中4 4Ca含量 ;应用感应耦合等离子质谱法测定粪便中58Fe和70 Zn的丰度及镝的含量 ,计算铁、锌的表观吸收率 ,并以镝的回收率进行校正。结果　豆粉组、牛奶组和去植酸豆粉组的铁吸收率分别为 (6 7± 3 8) %、(1 5 5± 9 2 ) %和 (2 0 6± 7 3) % ,钙吸收率分别为 (43 5±1 0 7) %、(64 2± 1 1 4) %和 (50 9± 6 6) % ,锌吸收率分别为 (1 1 3± 6 5) %、(31 2± 1 0 4) %和 (2 0 1±7 4) %。强化豆粉经去除植酸处理后 ,钙、铁、锌的吸收率显著高于未去植酸的豆粉 ;牛奶中钙和锌的吸收率高于去植酸强化豆粉 ;经去除植酸处理后的豆粉中铁吸收率高于牛奶 ,但差异无显著性。我国儿童由于     

补钙对12～17岁青少年锌、铁吸收率的影响

目的通过代谢平衡实验探讨补钙对中国青春期少年锌、铁吸收率的影响。方法从320名参加1年补钙实验的4组12~17岁少年中,每组随机抽取男、女生各10人,共80人。采用代谢平衡的方法,收集研究对象10天内摄入的食品、排出的粪便和尿液样品,用电感耦合等离子体发射光谱法测定样品中的钙、铁、锌含量。结果不同补钙组之间钙摄入量有差异,但铁、锌摄入量差异无显著性。不同补钙组之间钙、铁、锌的表观吸收率差异无显著性。男生钙、铁、锌的表观吸收率平均为69.4%、12.5%和29.9%,女生的分别为46.4%、20.9%和35.3%。铁的表观吸收率与青春发育水平有关。男生钙摄入量为600~800mg/d时,钙、铁、锌的表观吸收率均处于相对较高水平(75.3%、23.2%和36.4%)。结论钙摄入量低于1400mg/d时,不影响12~17岁少年锌、铁的吸收率。当男生钙摄入量为600~800mg/d时,更有助于钙、铁、锌的吸收。     

应用稳定性同位素^70锌中子活化法对缺锌儿童膳食锌吸收率的测定

本文以5—7岁整托幼儿园12名缺锌儿童为实验对象,实验前其发锌平均含量为:73.5±19.0ppm 锌儿童随机分为三组:A、锌摄入量6.1mg/日、B、10mg/日和C38.1mg/日。应用稳定性同位素~(70)锌中子活化分析法对三种膳食锌摄入量儿童,作了锌吸收率分别为:29.6±16.7％、33.9±6.8％、和23.1±2.5％。结果说明:①在理想的平衡膳食条件下锌的吸收率最高;②强化硫酸锌达到一定量(C组)会降低锌的吸收率。本文还对应用稳定性同位素~(70)锌中子活化法测定人体膳食锌吸收率产生误差的条件进行了分析。     

彝、藏族青年男子膳食蛋白质吸收利用研究

目的　探讨、比较彝、藏族青年男子膳食蛋白质来源与人体吸收利用情况 ,为完善我国膳食蛋白质推荐摄入量提供基础数据。方法　以凉山彝族自治州和阿坝藏族羌族自治州两个学校的 18～ 2 2岁男子为受试对象 ,采用人体氮平衡试验 ,对其进行为期 14天的代谢试验 ,收集制备 9天的膳食、粪便和尿等样品 ,以半微量凯氏定氮法测定样品氮含量 ,计算分析蛋白质吸收利用指标。结果　彝族青年男子蛋白质摄入量为71 5 5g d ,蛋白质表观消化率为 73. 19% ,真消化率、生物价、净利用率的估算值分别为 79. 79%、4 7. 5 8%、38. 17% ,氮平衡为 0 . 71g d。藏族相应以上指标的数据为 94 . 33g d、86 . 6 9%、91 .4 3%、4 8. 0 7%、4 4. 0 0 %和3 .16g d。结论　藏族青年男子膳食蛋白质的供给与吸收利用状况优于彝族 ,但两者均能保持机体正氮平衡。     

青春前期儿童膳食中铁的吸收状况研究

目的探讨青春前期儿童膳食铁的吸收率及相关影响因素。方法选择60名北京地区青春前期儿童,男女各半,依当地饮食习惯制定食谱,进行为期11d的代谢平衡试验,收集试验期内全部粪便样品,以双份饭法收集膳食及水样。样品经冷冻干燥、粉碎、微波消解后,以原子吸收法(AAS)测定铁量,同时对膳食样品中可能影响铁吸收的因子含量进行测定,并以代谢平衡法(MB法)测定铁吸收率。结果男、女性儿童铁的吸收率(%)为8.05±0.90和9.13±0.57,女性显著高于男性,(t=2.38,P<0.05),日均铁摄入量(mg)分别为13.6±2.4和12.8±1.7,分别占推荐营养素摄入量(RNI)的85.0%和71.1%;蛋白质日摄入量(g)分别为75.5±4.1和69.3±6.2,分别占RNI的107.8%和106.6%;维生素C(VC)摄入量(mg)分别为43.2±3.6和38.9±2.1,占RNI的48.0%和43.2%,低于推荐量;膳食纤维和植酸摄入量(g)分别为16.3±3.5、15.1±2.0和1.2±0.2、1.0±0.3。结论北京地区青春前期儿童铁的吸收率仍处于较低水平,女性高于男性。建议在增加膳食中血红素铁和VC摄入的同时,适当降低植酸和纤维素的摄入,以提高铁的吸收率。     

[Phytate][calcium]/[zinc] ratios in Asian immigrant lacto-ovo vegetarian diets and their relationship to zinc nutriture

Lacto-ovo vegetarians often have low zinc intakes coupled with concomitant high intakes of dietary fiber, phytate and calcium. The latter two dietary components appear to exert a synergistic inhibitory effect on zinc absorption. In this study 30 1-day diet composites were prepared for analysis from 3-day weighed diet records completed by 112 Asian immigrants consuming predominantly lacto-ovo vegetarian diets and compared with 30 omniverous diet composites. Analysed mean (±S.D.) daily intakes were: energy (kcal) 1892±445, calcium (mg) 1093±467, zinc (mg) 8.5±4.5, phytate (mg) 1487±791, neutral detergent fiber (g) 26.8±13.2. Median phytate: Zn molar ratio for Punjabi diets was 17.7 (range=5-50) and median [phytate][Ca]/[Zn] molar ratio was 475.4 (range=48-1150) compared with median values of 8.3 and 130.9 respectively for omniverous diets. Thirty-seven percent of the Punjabi diets had phytate:Zn ratios>20 and 80% had [phytate][Ca]/[Zn] ratios>200, levels shown to jeopardize zinc status in man. Thirty-two percent of the Punjabi subjects had low serum zinc levels (ie<70 g/dl) which may be associated with the unusually high dietary [phytate][Ca]/[Zn] ratios. The latter are attributed to high intakes of unleavened wholemeal chapatti bread, dairy products, and low intakes of flesh foods.     

Bioavailability of calcium and zinc from cow's milk-based versus soya-based infant food

A modified continuous flow dialysis in vitro method was used to study the availability of calcium and zinc from cow's milk-based versus soya-based infant food. First and second age infant formulae, milk for pre-schoolers and cow's milk were studied. The elemental content of the samples and dialysate fractions was determined by flame atomic absorption spectrometry. The relative availability of calcium and zinc from the soya-based first age infant formula (calcium: 31.6 ± 0.5%, zinc: 17.8 ± 1.8%), from the soya-based second age infant formula (calcium: 46.1 ± 2.1%, zinc: 20.9 ± 1.4%) and from the soya milk for pre-schoolers (calcium: 32.6 ± 0.7%, zinc: 39.7 ± 2.1%) proved to be as good as or even better than from the first age infant formula (calcium: 21.9 ± 1.4%, zinc: 23.3 ± 4.1%), from the second age infant formula (calcium: 31.0 ± 2.5%, zinc: 14.6 ± 0.7%) and from the milk for pre-schoolers (calcium: 27.7 ± 0.6%, zinc: 23.7 ± 2.8%) based on cow's milk. A similar relative availability from semi-skimmed cow's milk and soya milk was reported for calcium (31.5 ± 0.8% and 31.2 ± 1.7% respectively), as well as a much higher availability of zinc from soya milk than from cow's milk (55.7 ± 5.3% and 20.6 ± 3.0% respectively). Enrichment of soya milk with calcium results in a higher calcium availability (46.4 ± 1.9%), but a lower zinc availability (38.5 ± 2.6%) in comparison with the availability from non-enriched soya milk. The apparent absence of inhibitory effects of soya on the availability of calcium and zinc from infant food certainly is a positive finding for the about 10% of Belgian infants which are currently nourished with infant food based on derivatives of soya. According to these results no impaired calcium or zinc status should be feared for in this group of infants.     

Effects of high compared with low calcium intake on calcium absorption and incorporation of iron by red blood cells in small children.

BACKGROUND: The potential benefits of increasing calcium intake in small children must be balanced with the potential risk to iron utilization from high calcium intakes. OBJECTIVE: This study was designed to evaluate the relation between calcium intake and calcium absorption and iron incorporation into red blood cells. DESIGN: We performed a multitracer, crossover study of the absorption of calcium and red blood cell incorporation of iron in 11 preschool children aged 3-5 y who had been adapted for 5 wk to low- (502 +/- 99 mg) and high- (1180 +/- 117 mg) calcium diets. Stable-isotope studies were performed by using 44Ca and 58Fe given orally with meals and 46Ca given intravenously. RESULTS: Iron incorporation into red blood cells 14 d postdosing was similar (6.9 +/- 4.2% compared with 7.9 +/- 5.5%; NS) with the low- and high-calcium diets, respectively. Total calcium absorption (181 +/- 50 compared with 277 +/- 91 mg/d; P = 0.002) was greater in children with the higher calcium intake. CONCLUSIONS: Our findings indicate that small children may benefit from calcium intakes similar to those recommended for older children without adverse effects on dietary iron utilization.     

500例城市学前儿童血清钙锌铜铁含量调查

目的 :测定城市学前儿童血清钙、铁、锌、铜的含量以便了解必需元素的营养水平。方法 :采用化学比色法 ,在日立 71 70全自动生化分析仪上测定。结果 :钙、锌、铜、铁的含量分别为2 .38± 0 .1 5 mmol/L、1 5 .86± 3.2 4、1 5 .2 0± 4.5 6、1 7.73± 4.1 1 μmol/L;大多数结果均在正常参考范围内 ( x± 2 s)。轻度缺乏的比例分别为 4.4%、1 .6%、0 %、5 .6%。结论 :大多数城市学前儿童血清中钙、锌、铜、铁的水平正常 ,仅有很少数儿童血清中钙、锌、铁轻度缺乏     

胸、腹水中微量元素含量测定的临床意义

目的探讨结核性胸水、肝硬化腹水、肿瘤胸腹水与非结核性炎症性胸腹水中的铜、锌、钙、镁、铁含量是否一致。方法利用原子吸收的方法测定其胸腹水中的铜、锌、钙、镁、铁含量。结果25例结核性胸腹水均值分别为:铜14.30±4.01、锌24.60±4.00、钙1380±200、镁920±58、铁33±11.7。21例肝硬化胸腹水的均值分别为:铜14.70±1.70、锌24.40±1.60、钙1350±89、镁940±48,18例肿瘤病人胸腹水均值分别为:铜14.10±6.60、锌26.10±7.80、钙1220±398、镁1040±20、铁7.4±3.8。21例非结核炎症性(简称炎症性)胸腹水均值分别为:铜14.20±4.70、锌26.71±10.7、钙1315±216、镁910±79、铁10±3.5。经统计学处理:铜、锌、钙、镁含量没有显著差别(P>0.05),而铁含量有显著性意义(P<0.01)。结论结核性胸腹水中的铁含量最高,肝硬化胸腹水的铁含量最低。     

Calcium requirements: new estimations for men and women by cross-sectional statistical analyses of calcium balance data from metabolic studies

BACKGROUND: Low intakes of calcium are associated with an increased risk of both osteoporosis and cardiovascular disease. OBJECTIVE: To provide new estimates of the average calcium requirement for men and women, we determined the dietary calcium intake required to maintain neutral calcium balance. DESIGN: Calcium balance data [calcium intake -(fecal calcium + urinary calcium)] were collected from 155 subjects [women: n = 73; weight: 77.1 +/- 18.5 kg; age: 47.0 +/- 18.5 y (range: 20-75 y); men: n = 82; weight: 76.6 +/- 12.5 kg; age: 28.2 +/- 7.7 y (range: 19-64 y)] who participated in 19 feeding studies conducted in a metabolic unit. Balance data from the final 6-12 d of each dietary period (minimum length:18 d) of each study (1-9 observations per subject) were analyzed. Data were excluded if individual intakes of magnesium, copper, iron, phosphorus, or zinc fell below the estimated average requirements or exceeded the 99 th percentile of usual intakes from the 1994 Continuing Survey of Food Intakes by Individuals (for iron, above the upper limit). Daily intakes of calcium ranged between 415 and 1740 mg. The relation between intake and output was examined by fitting random coefficient models. Coefficients were included to test for sex and age differences. RESULTS: The models predicted a neutral calcium balance [defined as calcium output (Y) equal to calcium intake (C)] at intakes of 741 mg/d [95% prediction interval (PI): 507, 1035; Y = 148.29 + 0.80C], 9.4 mg kg body wt(-1) d(-1) [95% PI: 6.4, 12.9; Y = 1.44 + 0.85C], or 0.28 mg kcal(-1) d(-1) [95% PI: 0.19, 0.38; Y = 0.051 + 0.816C]. Neither age nor sex affected the estimates when calcium intakes were expressed as mg/d or as mg kg body wt(-1) d(-1). CONCLUSION: The findings suggest that the calcium requirement for men and women is lower than previously estimated.     

12～17岁少年钙代谢实验研究

目的通过钙代谢平衡实验探讨中国青春期少年的钙参考摄入量。方法从320名参与1年补钙实验4组12～17岁的少年中,每组随机抽取男、女生各10人,共80人。采用钙代谢平衡实验的方法。实验期共10d,膳食适应3d后,开始7d的代谢试验。收集研究对象试验期内摄入的食品、排出的粪便和尿液样品,用电感耦合等离子体发射光谱法测定样品中的钙含量。结果不同水平钙摄入组间的钙吸收量、粪钙排出量、钙储留量存在差异。钙表观吸收率女生平均为46.4%,男生68.7%。进行曲线拟合后,男生钙吸收率最高时的钙摄入量为665mg/d,女生钙吸收率达到平台时的钙摄入量为650mg。为了达到每日最大储留量,男生钙摄入量要达到545mg/d,女生要达到1055mg/d。结论中国12～17岁男生和女生的钙适宜摄入量有很大差别,男生钙适宜摄入量约为600～700mg/d,女生为1000～1100mg/d。