长期补充矿物质强化豆粉对12～14岁男童骨质转化指标的影响

目的　为了解长期饮用矿物质强化豆粉对儿童骨质健康的影响 ,比较去植酸强化矿物质豆粉、去植酸未强化矿物质豆粉和强化矿物质牛奶的生物学效应。方法　选择 1 2～ 1 4岁男性儿童补充豆粉 2个月 ,比较强化豆粉、未强化豆粉和强化牛奶对儿童骨质转化指标血清骨钙素、尿Ⅰ型胶原C末端肽链 (CTx)和血清碱性磷酸酶 (b ALP)的影响。结果　经 2个月的补充干预实验 ,强化豆粉组、未强化豆粉组和强化牛奶组干预后血清骨钙素水平增加值分别为 (1 6 42± 1 1 2 5)、(1 8 86± 1 1 57)和 (1 3 81± 1 0 0 6) μg/L ;血清骨特异性碱性磷酸酶水平显著下降 ,干预后下降值分别为 (0 2 8± 0 40 )、(0 2 6± 0 35)和 (0 1 7± 0 2 8) μmol·s- 1 ·L- 1 ;尿CTx水平亦显著下降 ,干预后下降值分别为 (349 1±380 3)、(2 60 4± 41 2 4)和 (354 4± 40 4 7) μg/L。 结论　长期饮用矿物质强化豆粉可有效增加儿童的骨质积累 ,改善儿童的钙营养状况     

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。     

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     

郑州市学龄前儿童全血中几种微量元素的含量

目的　了解郑州市学龄前儿童全血中铜、锌、铁、钙含量。方法　采集郑州市区及郊区 0～ 7岁健康儿童 660名的指血 ,采用原子吸收光谱分析法测定全血中铜、锌、铁、钙含量。结果　全血中铜、锌、铁、钙含量依次为 (1 9.2 2± 5 .2 1 )、(67.31± 7.55)、(8.69± 0 .60 )和 (1 .0 3± 0 .1 0 ) μmol L。大年龄组儿童 4种元素含量高于小年龄组 ,女性儿童血钙含量高于男性 ,市区儿童血锌、钙含量高于郊区儿童。 结论　不同年龄、不同性别、不同生活地区儿童全血中铜、锌、铁、钙含量不同     

铝染毒对大鼠海马中五种元素含量的影响

目的　探讨铝染毒后对大鼠海马中的锌、铁、铜、钙元素的含量的影响。方法　按大鼠体重 8%的进食量计算 ,分别在基础饲料中添加AlCl3·6H2 O ,分别按 0 (A) ,1 1 2 (B) ,55 9(C) ,1 1 1 9(D)mgAl3+ /kgBW 4个剂量组连续喂饲SD雄性大鼠 90d。然后 ,用原子吸收分光光度法测定大鼠海马中铝、锌、铁、铜和钙的含量。结果　铝经口染毒后 ,大鼠海马中铝含量明显升高 ,且有显著的剂量效应关系。对照组与 3个铝染毒剂量组脑海马中锌、铁、钙、铜含量分别为 :A组 (1 8 2 9± 2 48,2 4 86±1 97,48 69± 2 2 0 8,4 53± 0 99) μg/g ;B组 (1 7 2 2± 2 0 6 ,2 7 54± 2 87,42 79± 1 4 42 ,4 0 6± 0 41 ) μg/g ;C组 (1 4 46± 1 90 ,2 0 1 8± 2 79,2 9 95± 7 33 ,3 98± 0 2 5) μg/g;D组 (1 5 85± 2 54 ,2 0 96± 2 83 ,36 1 4± 1 2 66 ,4 53± 0 58) μg/g。与对照组比较 ,B、C组锌、铁含量均有显著性降低 ,C组的钙有显著性降低。结论　铝经口染毒会造成铝在脑海马中蓄积 ,并对其他一些必需元素在脑海马中的含量产生不同程度影响     

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。     

彝族成年男子膳食中铁、锌、钙的生物利用研究

目的:评价彝族成年男子膳食中铁、锌和钙的生物利用情况,为防治该人群矿物质缺乏病提供基础信息。方法:以代谢平衡法于现场对12名20~22岁彝族世居地的成年男子进行14d试验。试验开始,收集对象空腹血,检测血红蛋白、红细胞压积、血清铁蛋白、血浆锌和钙浓度。试验期间,收集4~12d试验膳及摄入试验膳后排出的粪便和尿样。应用火焰原子吸收法测定膳食、粪便和尿中三种矿物质的含量,分别计算出它们的表观吸收率、平衡状态和表观利用率。结果:彝族成年男子代表性膳食中铁、锌和钙的表观吸收率(%)分别为15.8±6.2、24.5±4.1、32.3±9.7;表观利用率(%)分别为1.9±5.7、12.8±4.3、5.5±15.9。平衡试验显示铁,锌,钙均为平衡,但钙的变动范围较大。结论:膳食中铁、锌摄入量能满足试验对象的需要量,而钙的摄入量则不能满足其需要量。三种矿物质的表观吸收率与表观利用率基本上与我国正常人相同。建议彝族居民增加钙含量高的食物摄入量,以预防钙缺乏。     

矮身材儿童血清锌、铁、铜、钙、镁含量分析

[目的]了解儿童血清锌、铁、铜、钙、镁对儿童生长发育的影响。[方法]测定生长发育迟缓儿血清中锌、铁、铜、钙、镁的含量并与正常对照组儿童比较分析。[结果]矮小儿童组血清锌、铁、铜、钙、镁为(13．0±3．8)、(15．6± 6．2)、(18．0±4．2)、(2141．3±157．6)、(782．6±77．5)μmol／L,除血清铜与正常对照组无差异外,血清锌、铁、钙、镁均低于正常对照组,差异有非常显著性(P<0．01)。矮小儿童组血清锌、铁、钙低于正常值下限例数的百分率分别为47．1％、 27．5％、39．2％,明显高于对照组,差异也有高度显著性(P<0．01),矮小儿童组血清铜、血清镁低于正常下限的百分率与正常对照组无差异(P>0．05)。[结论]血清锌、铁、钙、镁的含量影响儿童的生长发育,对矮小儿童应该在医生的指导下检测及补充相应的宏量和微量元素。     

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。     

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。     

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。     

Plasma zinc and copper levels of infants fed different milk formulas

The plasma zinc and copper levels of 32 full-term healthy infants, aged 3-4 months, using different infant formulas, were measured. The plasma zinc levels of infants using soy formula (45.1 +/- 19.1 micrograms/dl) and iron-fortified cow's milk formula (61.6 +/- 12.9 micrograms/dl) were significantly lower than those of the infants using cow's milk formula not fortified with iron (77.5 +/- 13.4 micrograms/dl). The plasma copper levels of the infants using the different formulas were not significantly different from each other. Fortification of infant formulas with high levels of iron may reduce the zinc absorption from such formulas.     

Effect of phytate removal on zinc absorption from soy formula

Low zinc bioavailability from soy formula may be the result of the formula's phytate content. We assessed the effect of phytate removal from soy formula on Zn absorption using infant rhesus monkeys and suckling rat pups as animal models. Zn absorption in monkeys, as determined by whole-body counting, was 65% from human milk, 54% from monkey milk, 60% from whey-predominant formula, 46% from casein-predominant formula, and only 27% from conventional soy formula (0.621 mmol phytate/L). In contrast, Zn absorption from dephytinized soy formula (0.067 mmol phytate/L) was 45%. In suckling rats, Zn absorption from conventional soy formula was only 16% vs 47% from dephytinized soy formula. Phytate concentration in a variety of experimental soy formulas was inversely correlated to Zn absorption. These results suggest that the low bioavailability of Zn from soy formula is a function of its phytate concentration and can be overcome by the removal of phytate.     

The effect of individual components of soy formula and cows' milk formula on zinc bioavailability

Zinc absorption from human milk, cows' milk formulas, and soy formulas was studied in human adults by a radioisotope technique using 65Zn and whole body counting. Individual dietary components were investigated for effects on zinc absorption. Phytate was found to have a strong inhibitory effect on zinc absorption; addition of phytate to cows' milk formula (yielding a phytate concentration similar to that of soy formula) resulted in a decrease in zinc absorption from 31 to 16% similar to the absorption for soy formula (14%). Carbohydrate source, calcium, and zinc levels of the diet did not affect zinc absorption significantly. Iron supplementation of cows' milk formula decreased zinc absorption from 24 to 18% although this decrease was not found to be significant (p less than 0.1). Absorption of zinc from a whey-adjusted cows' milk formula was higher (31%) than from a nonmodified cows' milk formula (22%). Increasing the zinc supplementation level in cows' milk formula but not in soy formula increased zinc absorption to approximate that from breast milk. It is suggested that reduction of phytate content of soy formula may be a more effective avenue of modification than increased level of zinc supplementation.     

铁强化中国酱油的研究——Ⅱ、铁强化酱油的人体铁吸收试验

31名健康成年自愿者,男11名,年龄18—48岁,女20名,年龄34—52岁 (均系采取节育措施的育龄妇女),用同位素~(55)Fe和~(59)Fe外标食物,分两批作人体铁吸收试验。其结果为:上海生产出口的海鸥牌瓶装酱油,原有铁(15.8mg铁/100ml)的吸收率几何均数(下同)为6.95％,酱油强化铁量为121mg铁/100ml时的铁吸收率为4.36％,该种铁强化酱油再强化维生素C(按铁:维生素C=1:2克分子量)则铁的吸收率为8.25％,几乎增加一倍。以7.5ml(一餐用量)的铁强化酱油(75mg铁/100ml)含铁量为5.6mg进行烹调蔬菜,以大米为主食,该餐中总铁量为8.9mg,铁的吸收率为5.65％,铁的吸收量为0.5mg;该餐另加瘦猪肉100g,则铁的吸收率为9.69％,铁的吸收量为1.08mg,肉能促进铁吸收一倍;但在该蔬菜餐后饮用龙井绿茶150ml(1.5g干茶叶泡成)其铁的吸收率降至3.09％,铁的吸收量为0.27mg,降低近一半。因此,应用加铁量为75mg铁/100ml的铁强化酱油,如按每人每天平均酱油的消耗量为15—20ml铁吸收率为5.65％计算,则铁的吸收量为0.63—0.85mg,可以基本满足一般人群每天对铁的需要量要求。如该种铁强化酱油同时强化维生素C,以铁吸收率增加一倍计算,则可满足孕妇、乳母、月经过多妇女及正在生长发育的儿童青少年对铁的特殊需要。     

Bioavailability of the calcium in fortified soy imitation milk, with some observations on method

BACKGROUND: Calcium-fortified soy milk is growing in popularity, particularly among vegetarians, but the bioavailability of its calcium was not previously known. Additionally, the validity of isotopic labeling methods for fortified liquid products had not been established. OBJECTIVES: The objectives of this study were to compare the bioavailability of the calcium in fortified soy milk with that of calcium in cow milk and to evaluate the method of labeling soy milk for bioavailability testing. DESIGN: A within-subject comparison of extrinsically labeled cow milk with intrinsically and extrinsically labeled soy milks was undertaken in 16 healthy men. In all tests, 300-mg Ca loads were given as a part of a light breakfast after an overnight fast. The milks were physically partitioned into liquid and solid phases to enable evaluation of tracer distribution. RESULTS: Calcium from intrinsically labeled soy milk was absorbed at only 75% the efficiency of calcium from cow milk. Extrinsic labeling of soy milk did not produce uniform tracer distribution throughout the liquid and solid phases and resulted in a 50% overestimate of true absorbability. CONCLUSION: Calcium-fortified soy milk does not constitute a calcium source comparable to cow milk, and extrinsic labeling of such calcium particulate suspensions does not produce the uniform tracer distribution needed for bioavailability testing. Hence, intrinsic labeling of the fortificant is required for such liquid suspensions.     

Absorption of calcium from milks enriched with fructo-oligosaccharides, caseinophosphopeptides, tricalcium phosphate, and milk solids

BACKGROUND: Adequate intakes of calcium are required for optimal bone health and protection against chronic disease. Dairy products are an excellent source of calcium. OBJECTIVE: The absorption of calcium from a range of fortified milks was measured in humans with the use of stable isotopes. DESIGN: Fifteen volunteers participated in a randomized, controlled, double-blind crossover study. Five types of semi-skimmed (1.9% fat) milk drinks were administered with a light breakfast: standard milk (control milk); milk enriched with calcium from milk solids and tricalcium phosphate [(TCP) MSS milk]; milk enriched with calcium from concentrated milk (CON milk); milk with added fructo-oligosaccharides [(FOSs) FOS milk]; and milk with added caseinophosphopeptides [(CPPs) CPP milk]. All the milks were labeled with 42Ca as CaCl2. The MSS milk was also labeled with 44Ca as TCP. The quantity of calcium in each drink was kept the same by varying the volume given. RESULTS: Calcium absorption did not differ significantly between the control milk and the calcium-fortified milks (MSS and CON milk) or the FOS and CPP milks. However, calcium absorption from the TCP added to the MSS milk was significantly higher than that from the control milk (27.5 +/- 7.6% and 24.5 +/- 7.3%, respectively; P = 0.003). CONCLUSIONS: Calcium-enriched milks are a valuable source of well-absorbed calcium. Absorption of added calcium as TCP was higher than that of calcium from the control milk, but the addition of FOSs or CPPs did not significantly increase calcium absorption. Further research is needed to ascertain the cost-effectiveness and public health benefits of consuming fortified milks.     

Na2EDTA enhances the absorption of iron and zinc from fortified rice flour in Sri Lankan children

Rice flour was proposed as a vehicle for iron and zinc fortification in Sri Lanka. Although widely consumed, rice flour has not been evaluated as a fortified food, and the absorption of minerals including iron and zinc from this flour is unknown. Determination of the bioavailability of these nutrients is a critical step before commencing a fortification program. We randomly divided 53 Sri Lankan schoolchildren ages 6-10 y into 4 groups that consumed a local dish prepared with 25 g of fortified rice flour labeled with one of the following: 1) (58)FeSO(4) 2) (58)FeSO(4) + Na(2)EDTA 3) (58)FeSO(4) + (67)ZnO or, 4) (58)FeSO(4) + Na(2)EDTA + (67)ZnO. The levels of iron and zinc were 60 mg/kg; the rice flour also contained folate at 2 mg/kg in each group. Na(2)EDTA was added at a Fe:Na(2)EDTA, 1:1 molar ratio. A total of 48 children completed the trial. Absorption of (58)Fe from a meal was significantly greater (P < 0.01) in the groups administered FeSO(4) + Na(2)EDTA (4.7 +/- 3.6%) than in those administered FeSO(4) without Na(2)EDTA (2.2 +/- 1.3%). Fractional absorption of zinc was 13.5 +/- 6.0% in the FeSO(4) + Na(2)EDTA group and 8.8 +/- 2.0% in the FeSO(4) group (P = 0.037). Although zinc absorption was low, our results demonstrated a benefit in using Na(2)EDTA to improve both iron and zinc absorption. We conclude that the fortification of rice flour is feasible, although additional strategies such as dephytinization or an increase in the level of iron and zinc fortification should be considered to obtain a higher proportion of the daily requirement of total absorbed iron and zinc.     

Effect of milk and lactose on zinc absorption in lactose-intolerant postmenopausal women

We evaluated the effect of lactose intolerance on intestinal zinc absorption under various test conditions in a group of postmenopausal women. Fractional zinc absorption was studied with a dual-isotope technique using 65Zn and 51Cr (as nonabsorbable fecal markers). We performed four absorption tests on sixteen subjects with water (control), whole cow milk, lactose-free cow milk and lactose alone. Mean (+/- SEM) fractional zinc absorption was 0.558 +/- 0.032 with water, 0.276 +/- 0.031 with milk, 0.246 +/- 0.028 with lactose-free milk and 0.564 +/- 0.051 with lactose. No significant differences in zinc absorption were found under any of the test conditions between lactose-tolerant and lactose-intolerant subjects. Milk and lactose-free milk significantly reduced zinc absorption in both groups.