Hydroxypropyl-distarch phosphate from Tapioca starch reduces zinc and iron absorption, but not calcium and magnesium absorption, in rats

Male rats were fed a fiber-free, purified diet containing either gelatinized tapioca starch that was not modified chemically (TS, 50 g/kg diet) or gelatinized chemically modified tapioca starch (CMS, 50 g/kg) for 21 d. TS was used as the control. The six kinds of gelatinized hydroxypropyl distarch phosphate (HDP) from tapioca with two different degrees of substitution (DS) and three different degrees of cross-linking (DC) were used as CMS sources. The wet weight and moisture of fecal output of the rats fed HDP with higher DS were 100 and 20% greater than that in the control rats, respectively. The weights of cecal wall and cecal contents were also 30 and 50% higher in the rats fed HDP with higher DS than those in the control rats. The pH of the cecal contents was more acidic in the rats fed HDP with higher DS than that in the control rats. Fecal excretion of bile acids was 40% higher in the rats fed HDP with higher DS than in the control rats. These effects of HDP were only slightly affected by the DC. The plasma cholesterol concentration was 16% lower in the rats fed HDP with higher DS and highest DC than in the control rats. The concentrations of liver lipids and plasma triglycerides and the cecal pool of organic acids were not affected by diet. The apparent absorptions of Ca and Mg were not affected by diet, but those of Zn and Fe were 75 and 70% lower in the rats fed HDP with higher DS than in the control rats. These results suggest that the physiological effects of HDP depend on the DS but not on the DC.     

Interaction of calcium and phosphate decreases ileal magnesium solubility and apparent magnesium absorption in rats.

We tested the hypothesis that increased intakes of calcium and phosphate lower magnesium solubility in the intestinal lumen, causing a decreased magnesium absorption. In in vitro experiments at a constant magnesium concentration, increasing calcium concentrations reduced magnesium solubility. This effect did not occur in the absence of phosphate. Increasing phosphate concentrations decreased the solubility of magnesium in the presence, but not in the absence, of calcium. These results suggest that the formation of an insoluble calcium-magnesium-phosphate complex determines magnesium solubility. To extend this concept to in vivo conditions, rats were fed purified diets containing a constant concentration of magnesium (16.4 mumol/g) but different concentrations of calcium (25, 100 or 175 mumol/g) and phosphate (58, 103 or 161 mumol/g). Increased intakes of calcium decreased magnesium solubility in the ileal lumen and lowered magnesium absorption. The latter result occurred only if the dietary phosphate concentration was at least 103 mumol/g. Increasing dietary phosphate concentrations reduced both magnesium solubility in the ileum and magnesium absorption, but only if the dietary calcium concentration was at least 100 mumol/g. These results support those obtained in vitro. We conclude that increased intakes of calcium and phosphate decrease magnesium absorption by the formation of an insoluble calcium-magnesium-phosphate complex in the intestinal lumen.     

Extrusion cooking of a high-fibre cereal product. 2. Effects on apparent absorption of zinc, iron, calcium, magnesium and phosphorus in humans

1. The effect of extrusion cooking, using mild conditions, of a high-fibre cereal product on apparent small bowel absorption of zinc, iron, calcium, magnesium and phosphorus was studied. 2. Seven ileostomy subjects were studied during two periods (each of 4 d), on a constant low-fibre diet supplemented with either 54 g/d of a bran-gluten-starch mixture or the corresponding extruded product. 3. The apparent absorption of Zn, Mg and P was significantly decreased (P less than 0.05) during the period with extruded product compared with the period with bran-gluten-starch. No difference was found for Fe and Ca. 4. The negative effect of extrusion cooking of a product containing phytic acid on availability of Zn, Mg and P was small but could be of nutritional relevance in foodstuffs that are consumed frequently and in infant formulas.     

Effects of resistant starch RS4 on magnesium and iron absorption in Wistar rats

The effect of resistant starch RS4 on apparent absorption of magnesium and iron was studied in Wistar rats. The rats (4 groups male n=12 and 4 groups female n=12) were fed for 4 weeks diets: control with wheat starch (K) and 3 diets with modified resistant starches (S1, S2, S3). After an adaptation period (14 d), rats were transferred to metabolic cages. Dietary intake and faeces were monitored for 3 days. Mg and Fe levels were assessed in diets and feces by atomic absorption spectrometry. Apparent absorption of minerals was calculated as mineral intake minus fecal excretion and expressed as persentage of intake. Our results confirmed that Mg apparent absorption in female rats fed diet with resistant starch S2 was significantly increased (+37%) compared with the control group.     

The effect of combined dietary iron, calcium and folic acid supplementation on apparent 65Zn absorption and zinc status in pregnant rats

In the present study the effect of combined iron, calcium and folic acid supplementation of the diet on 65Zn retention and zinc status was studied in the pregnant rat. Female Wistar rats were fed on a low- (8 micrograms/g) or high- (60 micrograms/g) Zn diet for 14 d and then mated overnight. After mating, half the rats were fed on the low- or high-Zn diet as before, whilst the other half were fed on similar diets supplemented with Fe, Ca and folic acid. The level of supplementation was chosen to reflect proportionately the possible increase in daily intakes of these nutrients by pregnant women. Rats which did not mate successfully were used as non-pregnant controls. On day 18 of pregnancy, each animal was given a meal of the appropriate diet labelled extrinsically with 65Zn, and on day 20 rats were killed. Carcass 65Zn retention was lower in pregnant and non-pregnant rats fed on the supplemented diets compared with those fed on the unsupplemented diets. Rats which consumed the supplemented diets throughout pregnancy had reduced plasma Zn concentrations but femur and fetal Zn concentrations were unaffected. Maternal femur Ca and fetal Fe concentrations were lower in the high-Zn groups compared with rats fed on low-Zn diets. It was concluded that the risk of inducing fetal Zn depletion as a consequence of Fe, Ca and folic acid supplementation during pregnancy appeared to be slight.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of 'fibre-filler' (F-plan diet) on iron, zinc and calcium absorption in rats

1. The availability of iron, zinc and calcium in a diet containing 400 g 'fibre-filler' (a mixture of bran, fruit and nuts, used in the F-plan diet)/kg diet (HF diet) was measured by whole-body counting in rats, using 59Fe, 65Zn and 47Ca as extrinsic labels, and compared with a diet of similar mineral content but no 'fibre-filler' (LF diet). Absorption of Fe and Ca was significantly higher from the HF than from the LF diet but there was no difference in Zn availability between the two diets. 2. The ability of rats given LF or HF diets for 3 or 28 d to absorb Fe, Zn and Ca was measured using ferrous sulphate, zinc chloride and calcium chloride in a cooked starch-sucrose (1:1 w/w) paste, extrinsically-labelled with the appropriate isotope. There was no difference in Fe absorption between the HF- and LF-fed groups but both Zn and Ca absorption were higher in LF- than in HF-fed animals after 3 and 28 d. 3. The mineral status of the animals given HF or LF diets for 28 d was examined, and there were no differences in blood haemoglobin, liver and bone Zn and plasma and bone Ca levels. The total liver Fe was significantly lower (P less than 0.05) in the HF-fed animals. 4. It was concluded that 'fibre-filler' did not have an adverse effect on Fe, Zn or Ca metabolism in rats although the long-term effect on Fe status warrants more detailed investigation. Further work is required to extend these studies to man.     

Interactions of lactose with calcium, magnesium and zinc in rats

The effects of lactose on utilization of calcium, magnesium and zinc were examined in two studies. In study 1, weanling male rats were fed either nonfat dry milk or CaHPO4, dolomite or a calcium chelate with supplemental lactose or sucrose for 27 d. In study 2, weanling male rats were fed diets based on milk or lactose-hydrolyzed milk for 28 d or in one meal labeled with 45Ca. Rats fed the lactose-hydrolyzed milk rather than the untreated milk digested their diet more completely, apparently absorbed total calcium and 45Ca less efficiently, and lost more calcium in urine but retained similar amounts of total calcium and 45Ca in bone. The effect of lactose hydrolysis on the absorption of 45Ca was similar whether rats were fed only one meal of the milk-based diets or were fed the diets chronically. The rats fed supplemental lactose (study 1) or unhydrolyzed milk (study 2) retained more magnesium and zinc in bone.     

Glucose polymer increases jejunal calcium, magnesium, and zinc absorption in humans

The present study investigated the effect of glucose polymer on jejunal calcium, magnesium, and zinc absorption in eight normal subjects, using the triple-lumen intestinal perfusion technique. For each subject, a 30-cm segment of jejunum was perfused for 60 min each with two different test solutions. When 4 mM glucose polymer was perfused net calcium absorption increased by fourfold (95 vs 488 mumol/30 cm/h), and net jejunal uptake of magnesium (393 mumol/30 cm/h) was observed, as compared to net magnesium secretion in the absence of glucose polymer. In addition, coadministration of glucose polymer doubled net zinc absorption (13 vs 29 mumol/30 cm/h). The rate of water absorption increased from 49 to 111 ml/30 cm/h. No further change in jejunal water and mineral absorption was observed when glucose polymer in the perfusate was increased from 4 to 8 mM. These results suggest that glucose polymer may have potential as an agent to significantly enhance mineral absorption.     

The effects of sugar-beet fibre and wheat bran on iron and zinc absorption in rats

The addition of 1 g sugar-beet fibre (Beta Fibre) to 3 g semi-synthetic diet resulted in a 54% increase in iron and a 39% increase in zinc absorption in rats. The same amount of non-starch polysaccharides fed as wheat bran (1.9 g) had no effect on Fe absorption but reduced Zn absorption by 9%. The inhibitory effect of wheat brain is probably due to its high phytate content, but there is, as yet, no explanation for the enhancement of Fe and Zn absorption caused by Beta Fibre. If the effect also occurs in man, it will have important implications for high-fibre diets and mineral nutrition.     

Effect of oat bran muffins on calcium absorption and calcium, phosphorus, magnesium and zinc balance in men.

Metabolic balance studies were conducted in adult human males to investigate the effect of oat bran on the nitrogen, calcium, phosphorus, magnesium and zinc balance, on the intestinal absorption of calcium and on the endogenous fecal calcium, using 47CaCl2 as the tracer. A 40-d control period preceded a 32-d experimental period in which subjects consumed four oat bran muffins daily as part of a constant metabolic diet. No significant changes in the calcium, magnesium or zinc balances were observed, but the nitrogen and phosphorus balances increased. The net or apparent absorption of nitrogen, magnesium and phosphorus expressed per milligram of intake increased significantly in the oat bran period due to the added content of these nutrients in the oat bran muffins. The intake of the oat bran muffins led to a significant increase in urinary phosphorus and significant decreases in urinary calcium and 47Ca excretions. The intestinal absorption of calcium, determined with 47Ca, did not change, whereas the endogenous fecal calcium increased slightly but significantly.     

矮小身材儿童全血锌、铜、铁、钙、镁含量分析

目的:观察矮小身材儿童全血锌、铜、铁、钙、镁含量的变化并进行分析。方法:采用火焰原子吸收法检测88例矮小儿童的全血锌、铜、铁、钙、镁含量。结果:矮小儿童的低血锌、低血铜、低血铁、低血钙发生率分别为55.68%、28.41%、51.14%和71.59%,血镁均在正常范围内,未见5种金属元素升高者。低血锌、低血铜、低血铁发生率分别在家族性矮小、GHD、体质性等原因引起的矮小儿中最高,而低血钙率在3组矮小儿间无明显差别。结论:矮小身材儿童体内存在不同程度的锌、铜、铁、钙缺乏,且低血锌、低血铜、低血铁发生率在不同病因中存在差异,故对矮小儿童要注意适当补充锌、铜、铁、钙等金属元素。     

晕船对血清钙、磷、镁、铁、铜、锌的影响

目的探讨晕船对血清钙、磷、镁、铁、铜、锌的影响.方法以30名20～22岁男学员为研究对象,用全自动生化分析仪及原子吸收分光光度计测定出航前与晕船发生后的血清钙、磷、镁、铁、铜、锌.结果出航前受试者血清钙、磷、镁、锌、铁的含量依次为(2.17±0.03)、(0.88±0.03)、(0.93±0.01)mmol/L、(10.60±0.33)、(20.48±0.96)μmol/L,航行时,晕船发生后上述血清元素浓度分别为(2.44±0.08)、(1.42±0.05)、(1.13±0.03)mmol/L、(11.98±0.44)、(9.68±0.66)μmol/L,统计学比较差异有显著性;血清铜含量在航行前后分别为(14.29±1.10)和(13.67±0.56)μmol/L,无统计学差异.结论晕船对血清矿物质含量有显著影响,表现为血清钙、磷、镁、锌升高,血清铁下降,血清铜含量变化不显著.     

The influence of zinc, magnesium, and iron on calcium uptake in brush border membrane vesicles

The effects of adding increasing concentrations of magnesium (Mg), zinc (Zn), and iron (Fe) on calcium (Ca) uptake into rat brush border membrane vesicles was measured. At ratios of 1:1, based on the RDA, none of these minerals were found to significantly decrease calcium uptake. Mg, however, inhibited Ca uptake at an RDA ratio of 3:1 (Mg:Ca). At higher RDA ratios (Zn:Ca 10:1), Zn also decreased Ca uptake. In a comparison of the molar ratios of the above cations, Zn inhibited Ca uptake the most (0.12:1), possibly by competing directly at high-affinity Ca binding sites. Fe did not decrease Ca uptake but rather demonstrated an enhancing effect at high concentrations (20:1). When mixtures of the above divalent cations were studied, the effects on Ca uptake could largely be explained by the actions of the ions individually.     

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。     

500例儿童铜锌钙镁铁检测结果分析

目的 通过对500例儿童血样的5种元素进行检测,评价儿童血中微量元素的水平.方法 对500例儿童血样采用BH-5100五通道原子吸收光谱仪检测血锌、铁、钙、铜和镁的含量,并进行统计分析.结果 500例儿童血样中5种微量元素普遍缺乏,其中铁缺乏严重,占65.8%;其他缺乏的元素依次分别为:锌(44.4%)、钙(27.0%)、铜(16.4%)、镁(12.6%).铁缺乏率在不同的年龄组之间比较有极显著性差异(χ2=14.12,P<0.01),其他微量元素的缺乏率在不同年龄组中无显著性差异(均P>0.05).结论 乌鲁木齐市儿童铁缺乏严重,在临床诊断和治疗中应予以重视.     

Effects of dietary phytate, calcium and magnesium levels on zinc bioavailability to rats

Young rats were fed diets containing 12 mg Zn/kg and varied levels of sodium phytate for 21-day ad libitum feeding periods. In experiment 1, Ca levels were 0.3, 0.5, 0.8 and 1.0%, and phytate:Zn molar ratio varied between 0 and 50. In experiment 2, Ca was maintained at 0.3%, Mg levels were 0.07, 0.22 and 0.37%, and phytate:Zn molar ratios were 0, 10, 20 and 30 at each Mg level. Major response criteria were body weight gain and tibia Zn accumulation. Weight gain was not influenced by Ca level in the absence of phytate or by phytate at 0.3% Ca; it was increasingly depressed as phytate was increased and by each increase in Ca in the presence of phytate. Total tibia Zn content was decreased at the highest Ca level in the absence of phytate; increasing the phytate progressively depressed tibia Zn at all Ca levels. Mg and phytate additions did not affect weight gain. Tibia Zn tended to be depressed by Mg and by phytate but these effects were significant only at the highest levels of the combined additions. These data corroborate and extend previously published findings on Ca and phytate effects on Zn utilization and show bone Zn accumulation to be a more sensitive criterion than weight gain in this connection. They also indicate that Mg exerts a less pronounced effect on Zn utilization in phytate-containing diets than does Ca.     

Inhibitory effects of phytic acid and other inositol phosphates on zinc and calcium absorption in suckling rats

While it is known that phytic acid, inositol hexaphosphate, has a negative effect on zinc and calcium absorption, the effects of inositol which is phosphorylated to a lesser extent are less known. We have prepared inositol triphosphate (IP-3), tetraphosphate (IP-4), pentaphosphate (IP-5) and hexaphosphate (IP-6) by hydrolysis of sodium phytate and separation by ion-exchange chromatography and have studied their effect on zinc and calcium absorption. Using a suckling rat pup model, we found that liver uptake of 65Zn after 6 h was 5% of the total dose from solutions of IP-6, 19% from IP-5, 28% from IP-4, 29% from IP-3 and 31% from ZnCl2 (control). Non-absorbed calcium was 17%, 1.4%, 0.5%, 0.5% and 0.5% of the given dose of 45Ca, respectively. Thus, at a high degree of phosphorylation (IP-6, IP-5), zinc and calcium uptake was inhibited, while no effect was observed for the other phosphates. Consequently, total "phytate" analysis, which includes inositol phosphates with varying degrees of phosphorylation, can give misleading information with regard to mineral availability. In addition, even limited dephosphorylation of inositol hexaphosphate can have a positive effect on mineral absorption.     

全血铜、锌、钙、镁和铁参考区间调查与分析

目的:本研究拟对目前中国全血五元素(铜、锌、钙、镁、铁)检测实验室所应用的参考区间进行调查和分析,了解这些项目参考区间的应用现状.方法:采用基于Web方式的室间质量评价(EQA)软件系统,收集参加中国全血五元素参考区间调查的实验室上报数据,使用Microsoft Excel 2007和SPSS 13.0对数据进行统计分析.结果:222家实验室有效上报了参考区间调查结果,22～90家(10.1％ ～40.9％)实验室进行了参考区间分组.超过75％的实验室应用仪器试剂厂家说明书上的参考区间,超过50％的实验室对参考区间进行了验证.全血铜的参考区间数值从出生后开始逐渐升高,到7岁后逐渐下降;全血锌从出生后一直升高,到成年后参考区间达到最高数值;全血钙从出生后一直逐渐缓慢下降;全血镁因分组较少未发现参考区间根据年龄变化的明显趋势;全血铁从出生后参考区间数值一直随年龄的增长而升高.两个主流检测系统间除锌项目外其他项目参考区间存在统计学差异(P＜0.05).结论:目前我国还未建立中国人群儿童全血五元素项目的参考区间,建议进行相关研究并制定按年龄和检测方法分组的儿童全血五元素参考区间的卫生行业标准.     

Binding of iron by three starchy legumes in the presence of iron alone,with calcium or with calcium,zinc, magnesium and copper

Iron (Fe) binding capacity of butter beans, broad beans and lentils in the raw, cooked and fibre-rich fraction (FRF) forms; with Fe addition alone, with calcium (Ca) and with Ca, zinc (Zn), magnesium (Mg) and copper (Cu) at concentrations based on physiological and dietary considerations, was investigated in conditions simulating the small intestine. The FRFs were found to bind significantly more Fe, indicating the substantial role of dietary fibre in Fe binding. More Fe was bound to legumes studied when Fe was added together with Ca than separate Fe addition. Further more Fe binding was noted in the presence of Ca, Zn, Mg and Cu.