Levels Of Iron Supplementation Research Articles

Labile Iron Pool of Isolated Escherichia coli Cytosol Likely Includes Fe-ATP and Fe-Citrate but not Fe-Glutathione or Aqueous Fe

The existence of labile iron pools (LFePs) in biological systems has been recognized for decades, but their chemical composition remains uncertain. Here, the LFeP in cytosol from Escherichia coli was investigated. Mössbauer spectra of whole vs lysed cells indicated significant degradation of iron-sulfur clusters (ISCs), even using an unusually gentle lysis procedure; this demonstrated the fragility of ISCs. Moreover, the released iron contributed to the non-heme high-spin Fe(II) species in the cell, which likely included the LFeP. Cytosol batches isolated from cells grown with different levels of iron supplementation were passed through a 3 kDa cutoff membrane, and resulting flow-through-solutions (FTSs) were subjected to SEC-ICP-MS. Mössbauer spectroscopy was used to evaluate the oxidation states of standards. FTSs exhibited iron-detected peaks likely due to different forms of Fe-citrate and Fe-nucleotide triphosphate complexes. Fe-Glutathione (GSH) complexes were not detected using physiological concentrations of GSH mixed with either Fe(II) or Fe(III); Fe(II)-GSH was concluded not to be a significant component of the LFeP in E. coli under physiological conditions. Aqueous iron was also not present in significant concentrations in isolated cytosol and is unlikely a major component of the pool. Fe appeared to bind ATP more tightly than citrate, but ATP also hydrolyzed on the timescale of tens of hours. Isolated cytosol contained excess ligands that coordinated the added Fe(II) and Fe(III). The LFeP in healthy metabolically active cells is undoubtedly dominated by the Fe(II) state, but the LFeP is redox-active such that a fraction might be present as stable and soluble Fe(III) complexes especially under oxidatively stressed cellular conditions.

Effects of Organic Iron Supplementation on the Performance and Iron Content in the Egg Yolk of Laying Hens

An experiment was conducted to determine the efficacy of dietary iron-soy proteinate (Fe-SP) and iron-methionine chelate (Fe-Met) on the performance of laying hens and iron content in egg yolk. Eight hundred Hy-Line Brown laying hens of 68wk old were housed in 400 cages of 2 birds each. Two hundred birds (10 cages×10 replicates) were assigned to one of the following four treatments: Control; non supplementation with Fe-SP or Fe-Met, Fe-Met 100; 100ppm iron supplementation with Fe-Met, Fe-SP 100; 100ppm iron supplementation with Fe-SP, Fe-SP 200; 200ppm iron supplementation with Fe-SP. Results of 35d feeding trial showed that there were significant differences in egg production, egg weight, feed conversion ratio and Haugh unit among the treatments. Egg weight and Haugh unit of Fe-SP 200 were significantly higher than the control. Hen-day egg production and feed conversion ratio of Fe-SP 100 and Fe-SP 200 were not significantly different from those of the control. Eggshell color was significantly improved in the Fe supplementation treatments compared to the control. The iron content of egg-yolk was maximized 5wk after feeding supplemental Fe and that of Fe-SP 100 was highest being 16.6% higher than the control. There were no significant differences in iron content of egg-yolk between source and level of iron supplementation. Copper content in the egg-yolk was not significantly affected by treatments but zinc content was significantly increased in iron supplemented treatments at 5th week after feeding. In conclusion, Fe content of egg-yolk could be effectively increased by supplementing 100ppm iron as iron-soy proteinate for 5wks. No significant difference was found in Fe content of egg yolk between Fe-SP and Fe-Met.

Production of Iron Enriched Eggs of Laying Hens

An experiment was conducted to investigate the efficiency of transfer of dietary iron sources to eggs of laying hens. Eighty ISA-Brown laying birds of 30 wk old were housed in 40 cages of 2 birds each. Eight birds in four cages were assigned to one of the following ten treatments: T1; control, T2; 100 ppm iron supplementation with iron-methionine chelate (Fe-Met-100), T3; Fe-Met- 200, T4; Fe-Met-300, T5; 100 ppm iron supplementation with iron sulfate (FeSO4-100), T6; FeSO4-200, T7; FeSO4-300, T8; 100 ppm iron supplementation with Availa-Fe  (Availa-Fe-100), T9; Availa-Fe-200 and T10; Availa-Fe-300. Results of 40 d feeding trial showed that there were no consistent responses in laying performance by source and level of iron supplementation. However, eggshell strength and color were improved by Fe supplementation. Egg iron content was maximized at 10-15 days after feeding supplemental Fe. Fe- Met was the most effective source in enriching Fe of eggs followed by Availa-Fe and FeSO4. Increasing supplementary Fe level more than 100 ppm was not effective in Fe-Met and Availa-Fe treatments. Average Fe enrichment of 18% was achieved after feeding Fe-Met-100 for 15 d. In conclusion, enrichment of Fe in egg could be effectively achieved by supplementation of Fe-Met-100 for 15 d. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 12 : 1725-1728)

Optimization of Iron Supplementation for Enhanced Detection of Salmonella Enteritidis in Eggs

Mixed raw egg contents were inoculated with approximately 10 CFU of Salmonella Enteritidis and supplemented with 0 to 7 mg of FeSO4 per g of egg contents. Egg contents were then incubated at 37°C, and Salmonella Enteritidis colonies were enumerated for up to 106 h. Iron supplementation significantly enhanced the growth of Salmonella Enteritidis. Within the first 24 h of incubation, the optimum iron level for Salmonella Enteritidis growth in egg contents was between 0.2 and 2 mg of FeSO4 per g of egg contents. After 24 h of incubation at 37°C, Salmonella Enteritidis counts in eggs supplemented with 0.5 mg of FeSO4 per g of egg contents consistently reached approximately 1 × 109 CFU/ml, whereas Salmonella Enteritidis counts in eggs without iron supplementation varied from less than 5 CFU/ml to 8.4 × 106 CFU/ml. A 3 by 3 factorial design was used to study the effect of type of preenrichment and level of iron supplementation on the growth of Salmonella Enteritidis in egg contents. No significant differences in Salmonella Enteritidis counts between preenrichment and nonpreenrichment treatments were observed when egg contents were supplemented with 0.5 mg of FeSO4 per g of egg contents. It was concluded that preenrichment was not necessary for isolation of Salmonella Enteritidis from eggs. The effect of iron supplementation on the sensitivity of detection by the direct plating method was investigated. The direct plating method detected a significantly higher percentage of Salmonella Enteritidis in raw egg contents supplemented with 0.5 mg of FeSO4 per g of egg contents (90%) than in raw egg contents without iron supplementation (63.3%).

A randomized trial of two levels of iron supplementation and developmental outcome in low birth weight infants

Objectives: To investigate the effect of increased iron intakes on hematologic status and cognition in low birth weight infants. Study design: We randomly assigned 58 infants to receive formula with 13.4 mg iron/L (normal iron) or 20.7 mg iron/L (high iron). At baseline, discharge, and at 3, 6, 9, and 12 months’ corrected age, we assessed anthropometry; infections; red blood cell hemoglobin, catalase, glutathione peroxidase, red blood cell fragility (hydrogen peroxide test), and superoxide dismutase values; plasma malondialdehyde, ferritin, iron, transferrin, zinc and copper levels; and diet intake. Griffiths’ Development Assessment was done at 3, 6, 9, and 12 months only. Results: No statistical differences (P <.05) were noted for weight, catalase or malondialdehyde levels, red blood cell fragility, or Griffith’s Development Assessment. Iron intakes were greater in the high iron group except at 12 months. Hemoglobin (high iron, 123 ± 9; normal iron, 118 ± 8) was not different at 3 months (P =.07). Plasma zinc levels (high iron, 70 ± 14; normal iron, 89 ± 27) and copper levels (high iron, 115 ± 26; normal iron, 132 ± 27; P =.06) at 12 months suggested inhibition of absorption by high iron formula. Glutathione peroxidase levels were higher in the high iron group. The total number of respiratory tract infections was greater in the high iron group (3.3 ± 0.9) than in the normal iron group (2.5 ± 0.9). Conclusion: In terms of cognitive outcome, there is no advantage associated with elevated iron intake for low birth weight infants. (J Pediatr 2001;139:254-60)

Suplementação de Ferro para Poedeiras Comerciais de Segundo Ciclo de Produção

O objetivo deste trabalho foi avaliar os efeitos da suplementação de ferro, proveniente do sulfato ferroso (26% de ferro), em ração à base de milho e farelo de soja, sobre o desempenho, qualidade do ovo, deposição de ferro na gema e parâmetros sangüíneos de poedeiras comerciais no segundo ciclo de produção. Foram utilizadas 240 poedeiras comerciais Lohmann-LSL, oriundas de plantel comercial e submetidas a muda forçada com 72 semanas de idade, alojadas em galpão convencional de postura, em uma densidade de três aves por gaiola (25 x 45 x 40 cm). O delineamento experimental foi inteiramente casualizado, com os tratamentos constando níveis de 0, 20, 40, 60 e 80 ppm de ferro suplementar, com quatro repetições de 12 aves, e três períodos de avaliações de 28 dias cada. A ração utilizada foi à base de milho e farelo de soja, contendo 127 ppm de ferro analisado. A suplementação de ferro não interferiu no desempenho, na qualidade interna e externa dos ovos e nos parâmetros sangüíneos das poedeiras. O conteúdo de ferro na gema (mg/100g) elevou-se linearmente quando houve aumento da suplementação deste até o nível de 80 ppm, utilizado no presente trabalho.

Two levels of iron supplementation and developmental outcome, iron nutrition and adverse results in low birth weight infants: [formula omitted], K. Aziz, B. Simmons and W. Andrews. Depts. of Biochem. & Pediatrics, Memorial Univ., St. John's, NF., Canada

Two levels of iron supplementation and developmental outcome, iron nutrition and adverse results in low birth weight infants: [formula omitted], K. Aziz, B. Simmons and W. Andrews. Depts. of Biochem. & Pediatrics, Memorial Univ., St. John's, NF., Canada

Dose-related effects of dietary iron supplementation in producing hepatic iron overload in rats.

The influence of varying the level of supplemental dietary iron on the development of hepatic iron overload was examined in rats. Two days after giving birth, Porton rats were fed a diet supplemented with 0, 0.5, 1 or 2% carbonyl iron, to institute dietary iron supplementation to the young via breast milk. After weaning, the offspring continued to receive the assigned diet until 32 weeks of age. Liver biopsies were taken from some rats at 8, 16 and 24 weeks of age and from all rats at 32 weeks of age, for assessment of iron overload. For both male and female rats, hepatic iron content was increased in a dose-related manner by feeding supplemented diet. Hepatic iron content of male rats tended to reach a plateau after 8, 16 weeks of supplementation, while that of female rats continued to rise throughout the experimental period, such that the hepatic iron content of female rats was 2.8-fold that of similarly treated males at 32 weeks of age. Iron supplementation was associated with only moderate retardation of growth. By choosing an appropriate level of iron supplementation, good (grade III-IV) hepatic iron loading can be achieved with minimal adverse effects on the animals' overall health.

Effects of iron repletion on &amp;OV0312;O2max, endurance, and blood lactate in women

To determine the effects of an 8-wk dietary iron supplementation (100 mg.d-1) on low plasma ferritin concentration (< 20 ng.ml-1) and endurance, 20 active women (19-35 yr) were studied while performing a VO2max test and an endurance test (80% VO2max) on a cycle ergometer. Subjects were randomly placed in an iron supplement (IG) or a placebo group (PG) using a double-blind method. After treatment in the IG, ferritin levels were higher (22.5 +/- 3.4 vs 14.3 +/- 2.2 ng.ml-1; P < 0.05), Hb increased (12.8 +/- 0.4 to 14.1 +/- 0.2 g.dl-1; P < 0.05), and TIBC decreased (366.2 +/- 24.8 to 293.8 +/- 14.0 micrograms.dl-1; P < 0.05). Also after treatment the IG's VO2max was significantly greater (P < 0.05) than the PG value and their postendurance blood lactate decreased (5.03 +/- 0.44 to 3.85 +/- 0.6 mM.l-1; P < 0.05). Endurance time to exhaustion increased 38% (37.28 +/- 5.03 to 51.4 +/- 7.45 min) following iron treatment; however, this change was not statistically significant. The results suggest that this level of iron supplementation can reverse mild anemia, increase VO2max, and reduce blood lactate concentration after submaximal exercise.

The effect of normal and high dose iron supplementation on serum ferritin levels during pregnancy

SummaryThe effect of three levels of iron supplementation on serum ferritin levels was compared during normal pregnancy. Eight patients receiving no iron supplementation were compared with 13 patients receiving routine oral iron (105 mg elemental iron per day) and 10 patients receiving a high oral dose of iron (480 mg per day). The dramatic fall in serum ferritin levels in the unsupplemented and routinely supplemented women was reversed in those receiving high dose iron with no adverse effects on the fetus. This suggests that 480 mg iron per day causes an increase in iron stores regardless of the demands of pregnancy. In order to maintain total maternal iron levels, it may be beneficial to supplement the iron intake of pregnant women with an intermediate dose of 200 mg of elemental iron per day