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Background Long- term consumption of imbalanced diets, poor in dietary fibres, resulted in the prevalence of several nutritional pathologies. However, low digestible carbohydrates (LDC) have many beneficial effects, especially on energy intake, digestive physiology, and mineral absorption. Aim of the study To determine the digestive effects of a LDC, called NUTRIOSE® FB, its metabolisable energy (ME) value, and its effects on mineral absorption in humans. Methods Ten healthy young men were fed for 31 d periods a maintenance diet supplemented with either dextrose or the LDC at a level of 100 g DM/d, in six equal doses per d according to a cross-over design. After a 20 d adaptation period, food intake was determined for 11 days using the duplicate meal method, and faeces and urine were collected for 10 d for further analyses. Results Ingestion of the LDC did not cause severe digestive disorders, except excessive gas emission, and flatulence and slight abdominal pain in some subjects for intakes above 50 g DM/d. Wet and dry stool outputs increased by 45 and 70 %, respectively (P <0.02). In vitro enzymatic digestibility of the LDC was 15 (SD 1.5) %,and 9.2 (SD 8.3) % of the LDC was excreted in faeces (P < 0.001). The ME value of the LDC was 14.1 (SD 2.3) kJ/g DM, that is 14% less than the tabulated values of sucrose and starch. Its net energy value (NEV), estimated using three prediction equations, was 8.7,8.9, and 11.4 kJ/g DM. Ingestion of the LDC significantly increased the relative apparent absorption of Mg, and Mg retention by 67 % and 31 mg/d, respectively, tended to increase Ca apparent absorption (P=0.110) and Ca retention (P = 0.059), but did not significantly alter Zn parameters. Conclusion NUTRIOSE® FB can be used as a "bulking" agent, and substituted up to 50 g/d for usual maltodextrins without causing digestive disorders in healthy subjects. It would reduce intestinal transit disorders and energy intake, and im- prove magnesium and calcium absorption and retention. [ABSTRACT FROM AUTHOR]

Red wines contain many components such as polyphenols and ethanol that may influence mineral absorption. We report on studies in a rat model that were designed to investigate the extent to which short- and long-term intake of red wine or ethanol may influence (67)Zn and (65)Cu absorption in rats. Rats (n = 96) were divided into three groups, a control group that received demineralized water, a group that received red wine diluted with water (v/v) and an ethanol group that received 6% ethanol. Half of each group was used for the short-term study; the others were used for the long-term study. After 3 d (short-term study) or 28 d (long-term study) of beverage consumption, the rats were gavaged with 2 mL of solution containing 2027 nmol (67)Zn and 902 nmol (65)Cu. Subsequently, 3-d urinary and fecal collections were performed and analyzed for total and isotopic Zn and Cu. In the long-term study, blood, tibia and liver were also sampled for mineral status assessment. Neither short- nor long-term intake of red wine altered (67)Zn or (65)Cu absorption. In contrast, long-term (but not short-term) ethanol consumption significantly increased both (67)Zn and (65)Cu absorption compared with the control and red wine groups. The long-term consumption of ethanol or red wine did not affect blood or tissue Zn or Cu levels. In conclusion, short- or long-term consumption of red wine did not have a negative effect on intestinal absorption or tissue levels of zinc and Cu in rats. [ABSTRACT FROM AUTHOR]

The rhamnogalacturonan-II dimer (dRG-II) forms strong complexes in vitro with lead (Pb) and other selected cations. We examined the in vivo bioavailability of Pb complexed with dRG-II and the effect of unleaded dRG-II on the intestinal absorption and tissue retention of Pb in rats. Forty male Wistar rats were divided into four groups. Each group consumed a purified control diet for 3 wk or the same diet supplemented with: i) 3 mg of Pb/kg, ii) 0.5 g of leaded dRG-II/kg, or iii) 0.5 g of leaded dRG-II/kg and 4.5 g of unleaded dRG-II/kg. The leaded dRG-II provided approximately 3 mg of Pb/kg of diet. A chemical balance study was conducted during the last 5 d of the 3-wk study, and blood and organs were sampled for Pb and mineral analyses. The apparent intestinal absorptions of Pb were 62.3, 15.2, 11.8 and -0.1%, and Pb balances were 1.9, 9.6, 5.6 and -0.2 microg/d for the control and the three experimental groups, respectively. The Pb complexed with dRG-II was less available than Pb acetate, as reflected by significantly lower blood and tissue Pb levels. The addition of unleaded dRG-II decreased the intestinal absorption and the tissue retention of Pb significantly. We further found that the apparent absorption and status of magnesium, zinc and iron were unaffected by Pb treatment or dRG-II addition. We conclude that dRG-II may be useful in decreasing toxicity related to chronic Pb exposure. Human studies will be necessary however, to further evaluate the clinical utility of this beneficial effect. [ABSTRACT FROM AUTHOR]

Literature data on the bioavailability of various Mg forms provide scarce information on the best Mg salt to be used in animal and human supplementation. This study aimed to investigate the bioavailability of different forms of Mg in rats using Mg stable isotopes. Eighty male Wistar rats aged 6 weeks were fed a semi-purified Mg-depleted diet for three weeks. The rats were then randomised into ten groups and received, for two more weeks, the same diet repleted with Mg (550 mg Mg/kg) as: oxide, chloride, sulphate, carbonate, acetate, pidolate, citrate, gluconate, lactate or aspartate. After 10 days of Mg-repleted diet, the rats received orally 1.8 mg of an enriched 26Mg. Faeces and urine were then collected for 4 consecutive days. Isotope ratios in faeces and urine were determined. The Mg absorption values obtained varied from 50% to 67%. Organic Mg salts were slightly more available than inorganic Mg salts. Mg gluconate exhibited the highest Mg bioavailability of the ten Mg salts studied. Urinary 26Mg excretion varied from 0.20 mg to 0.33 mg, and feeding with the organic pidolate, citrate, gluconate and aspartate salts resulted in higher urinary 26Mg excretion than with inorganic salts. Ultimately, 26Mg retention was higher in the rats receiving the organic salts such as gluconate, lactate and aspartate than in those receiving the inorganic salts. Taken together, these results indicate that 26Mg is sufficiently bioavailable from the ten different Mg salts studied in the present experiment, although Mg gluconate exhibited the highest bioavailability under these experimental conditions.

Fermentable carbohydrates have been shown to be nondigestible by human enzymes in the small intestine but are fermented extensively in the large bowel to short-chain fatty acids (SCFAs), which can increase mineral absorption. It has been shown that feeding such carbohydrates including short-chain fructo-oligosaccharides (sc-FOSs) increases intestinal magnesium (Mg) absorption in animals, but their beneficial impact on Mg absorption in humans still remains to be established. Therefore, this work aimed to investigate the effect of moderate daily doses of sc-FOSs (10 g/day) on the intestinal absorption and status of Mg in postmenopausal women without hormone replacement therapy (HRT). Eleven healthy postmenopausal women aged 59 +/- 6 years (mean +/- SD) received for 5 weeks sc-FOS or sucrose (placebo) treatments according to a randomized, double-blind, crossover design separated by a washout period of at least 3 weeks. Subjects ingested 87.5 mg of stable isotope 25Mg together with a fecal marker. Subsequently, feces were collected for 5-7 days. An inductively coupled plasma mass spectrometer (ICP/MS) was used for 25Mg stable isotope measurements in feces, urine, and blood. Mg levels were assessed also at the beginning and at the end of each treatment in plasma, erythrocytes, and urine. These measurements allowed for the determination of net intestinal Mg absorption and Mg status. The results show that the addition of 10 g sc-FOS to the diet increased Mg absorption by 12.3%, from 30.2 +/- 5.0% (placebo treatment) to 33.9 +/- 7.2% (sc-FOS treatment; mean +/- SD; p < 0.02). This increase in intestinal Mg absorption was accompanied by an increase in plasma 25Mg level and led to a higher urinary 25Mg excretion. This is the first time that such an effect is shown in humans. The overall conclusion of this work is that the ingestion of moderate doses of sc-FOS did improve intestinal Mg absorption and status in postmenopausal women. Because of the important role of Mg in many cellular functions, such Mg absorption improvement may be particularly interesting when the dietary intake of Mg is limited.

This experiment was designed to compare the effect of ingestion of a wheat flours on mineral status and bone characteristics in rats. White flour was tested either without further mineral supplementation or with Mg, Fe, Zn and Cu supplementation. The flour diets were compared to a control purified diet. Four groups of 10 male Wistar rats each were fed one of the experimental diets for 6 wk and mineral status and tissue retention as well as bone characteristics were determined. As expected, mineral intake, except for calcium, was significantly lesser in rats fed the white flour diet than in the other groups. The rats fed the white flour diet had the lowest food intake, weight gain, fecal excretion and intestinal fermentation. The most important result was that Mg and Fe status were drastically lower in rats fed the white flour diet than in those fed whole flour or control diets. The status of these both elements were significantly improved by the mineral supplementation of white flour. There were no major significant differences between mineral-supplemented white flour and whole flour groups in mineral status. Furthermore, bone mineral densities (total, metaphyseal and diphyseal) were significantly lower in rats fed white flour diet compared to the other diet groups, while no significant difference was observed between the mineral-supplemented white flour, whole flour or control diet groups. In conclusion, the present work shows clearly the importance of mineral-supplementation of white wheat flour to sustain an adequate intake of minerals. Our results indicate also that the whole wheat flour did not negatively alter mineral bioavailability, in comparison to mineral supplemented white flour. Clinical studies are still needed to confirm these rat results in human.

The amount of dietary trace elements absorbed from a meal depends, among other factors, on the quantities of certain minor plant constituents present in the meal. These substances can act as ligands and bind trace elements in the digestive tract in available or unavailable forms for absorption. The present study was designed to investigate the extent to which different polyphenols (PP) may influence Zn and Cu absorption in rats. Different PP of nutritional interest (chlorogenic acid, caffeic acid, catechin and rutin) were studied using meals extrinsically-labelled with stable isotopes 67Zn and 65Cu. Male Wistar rats were fed on a non-labelled semi-synthetic diet containing (mg/kg) 38 Fe, 35 Zn and 7.5 Cu for 8 d. PP were dissolved in dimethyl sulfoxide as the solvent and added to the meal at 1 g/kg during 3 d before isotope administration and until the end of the experiment (a further 3 d). The control group received the dimethyl sulfoxide only. After overnight food deprivation, rats were fed on the labelled test meals (4 g diet +0.1 mg 67Zn and 0.1 mg 65Cu) with 0.5 mg Dy as a faecal marker. Faeces and urine pools were collected for 3 d and analysed for 67Zn and 65Cu isotopic enrichment using the inductively-coupled plasma mass spectrometry technique. Zn absorption was significantly less in rats fed on chlorogenic acid or caffeic acid than in the control group. Catechin ingestion non-significantly inhibited 67Zn absorption. However, the PP studied were without effect on Cu absorption. The study illustrates the effect of metal-binding phenolic compounds on mineral nutrition in the rat, and the possible importance of the effects of different foods rich in these compounds on mineral absorption in man.

On an experimental farm, five camels and five cows were fed with a similar basal diet over a 6-month period. They received an oral trace element supplement for 3 months (days 22-112). This supplement contained zinc and copper sulphate, and corresponded to twice the daily requirement generally recommended for cows. Plasma zinc and copper concentrations were significantly lower in camels (44 micrograms/100 mL for copper and 38 micrograms/100 mL for zinc) than in cows (106 and 83 micrograms/100 mL, respectively). The supplementation had no effect on the plasma zinc concentration in the camels in spite of the low observed values. The mean erythrocyte SOD activity was also significantly higher in the cows (2,404 +/- 211 IU/100 gHb) than in the camels (1,720 +/- 312 IU/100 gHb). In both species, no correlation was found between copper plasma concentration and erythrocyte SOD activity. In cows, a positive relationship was observed between plasma zinc concentration and SOD activity (r = 0.396). In contrast, a negative relationship was found in camels (r = -0.369). These results are discussed in relation to the physiological peculiarities of the camel.

The present work aimed to investigate the feasibility of using stable isotopes and inductively-coupled plasma mass spectrometry (ICP/MS) to study Mg absorption in rats. Male Wistar rats, aged 7 weeks and weighing 180 g, were used. They were fed on a semi-purified diet containing 1070 mg Mg/kg, and had free access to feed and distilled water. In the first experiment, after a 16 d adaptation period, two doses of enriched 25Mg (6 and 12 mg) were administered by oral intubation, faeces and urine were collected daily and blood was sampled. Isotope ratios were determined by ICP/MS. 'True' absorption values, using the faecal isotope data, were 0.63 and 0.56 in rats receiving 6 and 12 mg 25Mg respectively, while apparent absorption was 0.50 for two successive periods of metabolic balance studies. Moreover, the oral isotope administration resulted in a measurable isotopic enrichment in plasma within hours which was still detectable on the third day following the isotope administration. In the second experiment, investigating the double labelling technique, similar rats were dosed simultaneously with 5 mg 26Mg orally (premixed with diet) and 0.29 mg 25Mg intravenously. The calculated Mg true absorption values were very similar when calculated from blood or urine data (0.38) but were lower than that obtained from faecal data (0.50). The possible causes of such an unexpected difference and limits of the double labelling technique for Mg absorption are discussed here. Together these results indicate that although 25Mg and 26Mg isotopes have high natural abundance, the described methodology permits meaningful investigations of Mg bioavailability and metabolism.

A table was made of the composition of mineral and trace elements in different classes of French food items. The P, Ca, Mg, Fe, Cu, Zn, Mn, I and Se contents of the main categories of food are presented. The mineral and trace element intakes of the average French consumer were calculated from national survey data concerning all food items purchased by households. The intakes and the sources of the different elements are given related to the energy. These results were calculated for male and female adults receiving 2700 kcal and 2000 kcal, respectively, and compared with the recommended dietary allowances (RDA). Phosphorus and calcium intakes were adequate, as was iron for men. The intakes of Mg, Cu, Mn were between 80 and 100% of the RDA. For Zn, I, Se the intakes were lower (50-80% of the RDA). The iron deficiency observed in women is serious, and the selenium deficit in men may induce real biochemical subdeficiencies with clinical consequences.

A survey based on 838 samples of milk obtained from 537 dairies covering 70 of 95 districts in France was organized to assess iodine content of milk and its contribution to total intake. Iodine levels were significantly higher in winter than in summer. Very low iodine contents (less than 25 micrograms I/kg) were found in the eastern part of the country (the Vosges, Jura, and the Alpes) and the Massif Central. During milk processing, much of the iodine is lost in the whey. The other significant sources of dietary iodine are fish and eggs. Iodized salt is sold only to households and not to industry. Even if about 20% of the iodine is lost over the first 3 mo, salt remains the main source for this trace element. It is concluded that, if iodized salt is not provided systematically for both domestic and agro-industrial use, then milk may be the most important source of iodine. This key role may explain seasonal and geographical variations in the frequencies of goiter in France.

A poor hay, with a low proteic level, decreases the zinc availability in lambs. Increasing the sulfur level with methionine and sulfate, of such a diet, enhances zinc absorption. However, sulfur is not the only factor limiting zinc availability in a hypoproteic diet.

Three groups of ten young ewes (29 kg) received a basal diet or a diet enriched in sulphur (3 g/kg DM) or sulphur (3 g/kg DM) plus molybdenum (13 mg/kg DM). The total plasma copper increased in the S + Mo group. The trichloracetic acid (TCA) insoluble copper fraction of this group rose sharply from the second week of experiment. A decrease in ceruloplasmin oxidase activity could be detected in non-saturating or saturating substrate conditions in the enzyme assay, either with paraphenylenediamine or o-dianisidine as substrate. It was concluded that the decrease was due to failure of synthesis rather than inhibition. The plasma TCA insoluble copper fraction is thus the earliest and most reliable parameter for molybdenosis diagnosis in sheep.

Efficiency of zinc injection as metal or oxide suspended in purified oil has been compared with control in three groups of seven ewes (39 kg). The zinc injected as oxide is liberated more rapidly from the injection site and the plasma zinc reachs a higher level than with zinc metal. However the effect of zinc metal injection lasts longer. Plasma copper behaves as an inflammation index. It rises more with zinc oxide injection. Both forms, metal or oxide are well tolerated by sheep without any side effect. Zinc oxide may be injected for more intensive but shorter treatment when zinc metal offers the best delayed effect.

A method for the determination of iodine in plants is described. This method involves destruction of organic matter by alkaline incineration and automated spectrophotometric determination of iodide based on the Sandell and Kolthoff's reaction. The mean recovery of 131I was 93.4% (S.D. = 3.19)). For replicate analyses of different plant material, the coefficient of variation is between 3 and 5%.

A zinc deficient diet which is not semi-synthetic was tried on 20 male Limousin X Romanoff three and a half month-old sheep weighing 36 kg on average. This diet was composed of strawy hay sprayed with caramel containing urea and minerals. Compared to hay alone this diet is more appetizing to lambs and more equilibrated as to energy level and soluble nitrogen utilization. The deficiency appeared within a week in zinc plasma and progressed clinically within 100 days. The plasmic free zinc and alkaline phosphatase were not better criteria for the deficiency diagnosis than total plasmic zinc. Supplementing the diet to 50 or even 100 mg Zn/kg DM was insufficient to suppress the deficiency. Zinc injection, by contrast, restored zincemia to normal in ten days. Zinc deficiency treatment by oral route should be reconsidered.

The effect of increased dietary sulphur, copper and molybdate on the metabolism of 99Mo administered via the rumen or duodenum was examined. Duodenally administered 99MoO4= was efficiently and rapidly absorbed and excreted via the urine; dietary modifications did not alter this pattern although increased dietary S increased the excretion rate. The passge of 99MoO4= through the rumen led to chemical modification, so that, particularly at high S levels, most of the radioactivity remained in the feces; increased dietary Mo led to increased absorption whereas increased copper decreased absorption. Incorportion of radioactivity into the TCA insoluble plasma fraction was shown with increased dietary S and particularly when both dietary S and Mo were increased. The compatiblity of the results with the hypothesis of ruminal thiomolybdate formation and subsequent reaction with dietary or tissue copper is discussed.

The emergence and treatment kinetic of the vitamin B12 deficiency was studied in 4 adult male Texel sheep bearing rumen fistulas. A natural meadow-grass, low in cobalt (0.04 mg/g of dry matter) was distributed freely to the animals. After the emergence of the vitamin B12 deficiency, the animals received every day a 10 ml solution containing 0.5 mg of cobalt in the rumen. The ingestion of a cobalt-deficient hay provoked a great decrease in the synthesis of vitamin B12 during the first week. The serum content decreases more slowly, the deficiency threshold being reached after 7 weeks. A serious deficiency is apparent 10 weeks after the deficient diet was first distributed. The treatment applied to the animals has a rapid and spectacular effect. The synthesis returns to normal 72 hours after the start of intraruminal cobalt infusions. The animals are no longer deficient after 24 to 28 hours of treatment.

Iodine concentrations were determined in 848 samples of milk from tanks of 537 dairy factories collected in 1983 and 1984 during winter and summer. Industrial processing, like pasteurization, UHT sterilization and spray-drying, had no effect on iodine concentrations. Of the samples of bovine milk, 94.7% ranged between 10 to 250 μg/kg. Iodine in bovine milk averaged 97 and 93 μg/kg in the winter of 1983 and 1984, and 44 and 23 μg/kg in the summer of 1983 and 1984. The frequency of iodine concentrations above the 500 μg/kg limit was 0.5% in 1983 and 0.3% in 1984. Iodine in ovine milk varied from 116 to 1183 μg/kg. Of the ovine milk samples 53.3% were above 500 μg/kg. Thus the iodine content of milk, is not yet a health problem in France.