Apparent Selenium Absorption Research Articles

Effect of varied levels of selenium supplementation in nano form on growth, nutrient intake and digestibility in Wistar albino rats

Sixty three weaned male Wistar albino rats (124.3±3.1 g mean body weight) were divided into 9 treatment (T) groups following completely randomized design (CRD) and fed a common basal diet except for selenium (Se) source and levels. While in T1 (control), no Se was supplemented; in T2 and T3, 150 ppb Se was supplemented as nano Se and sodium selenite, respectively. The rats in T4, T5, T6 and T7 were supplemented nano Se at 75, 37.5, 18.75 and 9.375 ppb levels respectively. The rats in T8 and T9 were supplemented 300 ppb Se as nano Se and sodium selenite respectively. The experimental feeding lasted for a period of 13 weeks including a digestion trial of 5 days after 40 days of experimental feeding. The intake and digestibility of DM, OM, EE, CF, NFE and CP were similar (P>0.05) among different treatment groups, however CP digestibility was significantly (P 0.05) among the nine groups. The apparent Se absorption was significantly (P<0.001) higher in T3 supplemented with 150 ppb nano Se. The average daily gain (ADG) was significantly (P<0.05) higher and feed: gain ratio was significantly (P<0.05) lowered in T3 supplemented with 150 ppb nano Se. The results suggested that nano Se supplementation up to 300 ppb had no adverse effect on growth, nutrient intake and digestibility in male Wistar albino rats and nano Se supplementation at 150 ppb exerted a positive effect on growth, protein utilization and apparent selenium absorption in male Wistar albino rats.

Effects of dietary level of selenium and grain on digestive metabolism in lambs

The objective was to evaluate the effect of different levels of selenium with two levels of grain corn in the diets on ruminal, postruminal, and total tract digestion of nutrients, ruminal fermentation characteristics, and selenium balance in lambs. A split-plot design was used in four periods with repeated Latin square using eight Suffolk &amp;times; Dorset male lambs with four levels of selenium (sodium selenite, Na&lt;sub&gt;2&lt;/sub&gt;SeO&lt;sub&gt;3&lt;/sub&gt;), without adding selenium, 0.3, 0.6, and 0.9 mg of selenium/kg dry matter (DM) with 70 and 50% of corn grain in the diet. The four selenium levels affected organic matter as follows: starch, neutral detergent fibre, nitrogen and selenium excretion; selenium ruminal digestion; organic matter, neutral detergent fibre, nitrogen and selenium postruminal digestion; and organic matter, neutral detergent fibre, nitrogen and selenium total tract digestion (P &amp;lt; 0.05). Starch and organic matter flow decreased with 0.6 and 0.9 mg of selenium with the 70% grain diet (P&amp;nbsp;&amp;lt; 0.05). Selenium flow increased linearly with selenium levels (P &amp;lt; 0.01) with both levels of grain. Selenium supplementation increased linearly selenium concentration in ruminal fluid (P &amp;lt; 0.01), but did not affect other ruminal characteristics. Also, selenium absorption and retention was increased by selenium concentrations (P&amp;nbsp;&amp;lt; 0.01). The apparent absorption of selenium increased (31%, P &amp;lt; 0.01) with the 70% grain diet. In conclusion, the high content of nonstructural carbohydrates improved the availability of selenium and 0.9 mg of selenium/kg &lt;br /&gt;DM improved the absorption and availability of selenium. &amp;nbsp;

Selenium intakes, absorption, retention, and status in adolescent girls

Objectives To assess selenium intakes, absorption, retention, and status in healthy adolescent girls and the effect of calcium supplementation on selenium parameters. Design Annual 2-week study conducted each year for 3 consecutive years in which yearly selenium intakes, absorption, and retention and blood selenium status were measured. Setting A metabolic unit in a large metropolitan hospital located in Columbus, Ohio—a low selenium region of the United States. Subjects Healthy white girls aged 11 to 14 years (n=16) enrolled in a calcium balance study and randomly assigned to receive a placebo of methylcellulose (n=9) or a calcium supplement containing 1,000mg supplemental calcium as calcium citrate malate (n=7). Interventions Each subject consumed a diet with ∼100μg selenium/day during the yearly 2-week balance studies. Results Selenium status measurements (serum and erythrocyte selenium and glutathione peroxidase activity) were all within normal ranges for adults during the study. Apparent selenium absorption averaged 71%, 76%, and 74% for years 1,2, and 3 of the study, respectively, and did not vary significantly (P>.05). Average daily selenium retention did not differ among the years of the study (P>.05) and indicated that the usual selenium intake was ∼100μg daily. Measurements of selenium status and retention did not differ between calcium-supplemented and placebo groups. Conclusions An intake of ∼100μg selenium/day is the typical intake of the mineral among the subjects and appeared adequate to maintain selenium status in these healthy adolescent girls; in addition, calcium supplementation of 1,000mg daily does not have a negative impact on selenium parameters. J Am Diet Assoc. 2002;102:1082-1087.

Selenium Intakes, Absorption, Retention, and Status in Adolescent Girls

Objectives To assess selenium intakes, absorption, retention, and status in healthy adolescent girls and the effect of calcium supplementation on selenium parameters.Design Annual 2-week study conducted each year for 3 consecutive years in which yearly selenium intakes, absorption, and retention and blood selenium status were measured.Setting A metabolic unit in a large metropolitan hospital located in Columbus, Ohio—a low selenium region of the United States.Subjects Healthy white girls aged 11 to 14 years (n=16) enrolled in a calcium balance study and randomly assigned to receive a placebo of methylcellulose (n=9) or a calcium supplement containing 1,000mg supplemental calcium as calcium citrate malate (n=7).Interventions Each subject consumed a diet with ∼100μg selenium/day during the yearly 2-week balance studies.Results Selenium status measurements (serum and erythrocyte selenium and glutathione peroxidase activity) were all within normal ranges for adults during the study. Apparent selenium absorption averaged 71%, 76%, and 74% for years 1,2, and 3 of the study, respectively, and did not vary significantly (P>.05). Average daily selenium retention did not differ among the years of the study (P>.05) and indicated that the usual selenium intake was ∼100μg daily. Measurements of selenium status and retention did not differ between calcium-supplemented and placebo groups.Conclusions An intake of ∼100μg selenium/day is the typical intake of the mineral among the subjects and appeared adequate to maintain selenium status in these healthy adolescent girls; in addition, calcium supplementation of 1,000mg daily does not have a negative impact on selenium parameters. J Am Diet Assoc. 2002;102:1082-1087.

Absorption and retention of selenium from shrimps in man

This study was undertaken to evaluate the bioavailability of selenium in shrimps, a possible good source of selenium, by measurements of the absorption and retention of selenium and the effects on plasma selenium concentration and glutathione peroxidase activity. Twelve healthy young subjects (9F and 3M) received 100 g of shrimps each day for six weeks in addition to their habitual diet. In the third week of the study a balance period was inserted in which the subjects received all food from the department and collected faeces and urine over 5 days. Blood samples were collected at commencement of the study, after 2, 4, and 6 weeks. The selenium intake increased from 39.4 +/- 15.3 microg/d to 127 +/- 5.5 microg/d with the addition of shrimps. The apparent absorption of selenium from shrimps was 83 +/- 4%. Faecal and urinary selenium excretion was 32.5 +/- 17.0 microg/d and 21.2 +/- 9.0 microg/d, respectively and the total retention of selenium was 3.1 +/- 1.1 mg. Plasma selenium concentrations were 95.2 +/- 9.7 microg/L and 101.5 +/- 9.7 microg/L before and after six weeks of shrimp intake, respectively (p<0.05). Plasma and erythrocyte glutathione peroxidase activities were not influenced by shrimp intake. Thus, despite the high absorption and retention, plasma selenium concentrations were only moderately affected by an increase in selenium intake of about 100 microg/d in the chemical forms found in shrimp. Whether the accumulation of selenium from shrimps in tissues may represent a potential hazard is to be further investigated.

Selenium bioavailability in the regional urban diet of Mato Grosso, Brazil

Selenium concentration and bioavailability were assessed in a common Mato Grosso urban regional diet (RUDMT), using 52 Wistar male weanling rats, weighing 56.2 ± 1.4 g. Thirty-two rats were fed a casein diet that was free of selenium, vitamin E and methionine and contained anti-oxidant-free oil for a 30 day period in order to induce a selenium deficiency. The remaining rats were fed on a casein diet, forming control group I, with 0.10μg of selenium per gram of diet. After selenium deficiency had been established, 24 rats were divided into three groups which were fed on three different diets for 25 days: (i) RUDMT group, with 0.02 μg of selenium per gram of diet; (ii) control group II, with 0.10μg of selenium per gram of diet; and (iii) pair-feeding group, with 0.04 μg of selenium per gram of diet. During this latter period, the control group I without depletion continued to be fed on the casein diet with 0.10 μg of selenium per gram of diet. Apparent selenium absorption, selenium concentration and the enz...

Selenium bioavailability in a regional diet of São Paulo

The selenium (Se) bioavailability of a diet consumed by a low income population in the State of São Paulo, Brazil, was assessed in Wistar rats by determining the apparent selenium absorption and retention, as well as the selenium concentration and level of glutathione peroxidase activity in plasma and liver. The study used three groups of eight selenium-depleted rats which were given the following treatments: group 1, diet prepared based on the São Paulo regional diet, with 0.02 μg/g Se; group 2, a casein-based diet with 0.03 μg/g Se; and group 3, a casein-based diet with 0.1 μg/g Se. All diets were isoproteic. The diet based on the regional diet of São Paulo presented the smallest selenium bioavailability as assessed by the apparent absorption index, the level of selenium in plasma and liver and the glutathione peroxidase activity in plasma and hepatic cytosol. It seems that confounding factors such as deficiency in vitamins and essential amino acids, as well as the fibre fraction, might have contributed to the low selenium bioavailability recorded in this diet.

Effect of Dietary Calcium on Selenium Absorption by the Nonlactating Dairy Cow1,2,3

Eleven nonlactating Holstein cows in late gestation were used to study the effect of dietary calcium concentration on apparent selenium absorption. Digestion trials with total collection helped to estimate apparent absorption of specific nutrients. Mean daily selenium intake ranged from 900 to 1700μg per day. Regression analysis indicated apparent selenium absorption was maximum when dietary calcium was .8% of dry matter intake. Amounts of dietary calcium less or greater than .8% of dry matter intake reduced apparent selenium absorption. Dietary calcium quantitatively affected apparent selenium absorption in amounts of nutritional significance when selenium was provided from natural feedstuffs.

Quantitative and qualitative aspects of selenium utilization in pregnant and nonpregnant women: an application of stable isotope methodology

Selenium utilization of women in early and late pregnancy was compared to that of nonpregnant controls. A defined diet providing about 150 µg Se/day was fed for 20 days, and selenium balance was measured during the last 12 days. Net selenium retentions of the women in early and late pregnancy were 10 and 23 µg/day, respectively, but probably are inflated estimates of the increased selenium requirement during pregnancy. Apparent absorption of selenium was 80% for all three groups. Pregnant women tended to conserve selenium by decreasing urinary selenium excretion. Those observations were corroborated by monitoring the urinary and fecal excretion of 40 µg of a stable isotope of selenium (76Se) from intrinsically labeled egg. The isotope data also indicated that recent selenium intake was incorporated into a long-term selenium pool. Mean glutathione peroxidase activity was lower in plasma and higher in platelets in the pregnant women as compared to controls, but the physiological significance of those observations is unknown.