• The Korean Journal of Food And Nutrition
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• v.15 no.1
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• pp.7-11
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• 2002

This study was performed to estimate fille zinc absorption, excretion, and balance of preschool children in Pohang and to evaluate the relationship zinc absorption and related variables. To determine the zinc absorption and excretion, duplicate food samples, pooled faces and urine samples were collected for 3 consecutive days in 21 preschool children. The mean fecal and urine excretions were 7.03mg/day and 0.16mg/day far the boys and 5.87mg/day and 0.15mg/day for the girls. Analyzed daily mean zinc intake was 10.45mg/day for the boys and 7.80mg/day for the girls. The mean ,apparent absorption rate and balance were 29.7% and 3.25mg for the boys and 23.3%, 1.78mg for the girls. Although the mean apparent absorption rate and balance of boys tended to be higher, there was no significant difference between boys and girls. In this study, subjects showed the positive balance except one. Fecal zinc loss reflected dietary zinc (p < 0.01), but urinary zinc loss was unaffected by zinc intake. There was a positive relationship between zinc apparent absorption and zinc balance (p<0.01). These results show that the zinc absorption and balance were favorable.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.542-549
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• 1995

This study was conducted to obtain accurate data on intake, excretion, apparent digestibility and balance of zinc which Korean take in habitually. This study applied to the seven high school girls from 15 to 16 years old. Their food intake, feces and urine were collected and intake and excretion of zinc in them were measured by atomic absorption spectrophotometry. The measurement continued for four weeks while they maintained their normal living pattern and body weight. Each girl's daily intake and excretion of zinc were measured and apparent digestibility and balance were also studied. Each girl's daily mean intake, fecal excretion and apparent digestibility of zinc were $9.26{\pm}2.30mg,\;3.31{\pm}2.15mg,\;and\;62.92{\pm}3.22%$, respectively. The urinary excretion of zinc was $3.23{\pm}1.03mg$ and showed the positive balance of $2.61{\pm}2.91mg$.

• Korean Journal of Community Nutrition
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• v.3 no.1
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• pp.12-20
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• 1998

In this study, the food intake, feces and urine of 14 primary school age boys and girls were collected and intake and excretion of iron and zinc were measured. The boys and girls were 8-12 years old and measurement continued for four weeks during which they maintained their normal living pattern. Each boy's and girl's daily intake and excretion of iron and zinc were measured and apparent digestibility and balance were also calculated. The results are as follows. Mean daily intake of iron was $14.9\pm{0.6mg}$ for the boys and $12.4\pm{0.5mg}$ for the girls. Mean daily intake of zinc was $11.8\pm{1.2mg}$ for the boys and $11.5\pm{0.4mg}$ for the girls. Mean daily fecal loss and apparent digestibility of iron was $6.1\pm{0.3mg}$ and $58.8\pm{2.0%}$ for the boys and $6.8\pm{0.1mg}$ and $44.1\pm{2.0%}$ for the girls. Mean daily fecal loss and apparent digestibility of zinc was $9.3\pm{0.2mg}$ and $14.4\pm{5.1%}$ for the boys and $9.7\pm{0.4mg}$ and $14.3\pm{4.3%}$ for the girls. Mean daily urinary loss of iron was $1.1\pm{0.1mg}$ and showed the positive balance of $7.86\pm{0.6mg}$ for the boys and $0.5\pm{0.1mg}$ and showed the positive balance of $5.14\pm{0.4mg}$ for the girls. Mean daily urinary loss of zinc was $0.5\pm{0.1mg}$ and showed the positive balance of $1.03\pm{0.6mg}$ for the girls.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.346-353
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• 1995

The dietary requirement for zinc to maintain optimally the various metabolic and physiological funcitons is still under study. Human beings adapt to reductions in zinc intake by reducing the rate of growth or zinc excretion. Reductions in dietary zinc beyond the capacity to maintain homeostasis lead to utilization of zinc from an exchangeable pool. Loss of a small, critical amount of zinc from this pool leads to both biochemical and clinical signs of zinc deficiency. Zinc requirements have been assessed by balance studies and factorial method. As tissue zinc status influences endogenous losses and the dietary needs, individuls in good status may require higher amounts of zinc than those in poor status. While plasma zinc is insensitive to reducitons in dietary zinc, it is regarded as a valid, useful indicator of the exchangeable pool of zinc. Plasma metallothionein concentrations may prove useful for identifying poor zinc status. It has been suggested that functional end point measurement is the new direciton for zinc requirement. However, determination of the functional response to a marginal zinc intake is difficult because of the lack of a specific, sensitive indicator of zinc status. Presently, no good method for assessment of human zinc requirements exists.

• Korean Journal of Community Nutrition
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• v.3 no.2
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• pp.218-227
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• 1998

This study was performed to investigate the effects of dietary protein and calcium levels on iron and zinc balance in eight healthy Korean young women. The 20-day metabolic study consisted of a 2-day adaptation period followed by three 6-day experimental periods. Three experimental diets were the low protein-low calcium(LProLCa ; protein 44g, Ca 422mg), the high protein-low calcium(HProLCa ; 'protein 85g, Ca 365mg) and the high protein-high calcium (HProHCa ; protein 84g, Ca 727mg). Apparent absorption and balance of iron and zinc were significantly higher when subjects were fed high protein-low calcium diet than low protein-low calcium diet. The elevation of dietary calcium significantly depressed the apparent absorption of iron and zinc. The levels of serum iron and zinc were likely to be increased with a high protein diet, but the differences were not significant. There was a strong correlation(r=O.99) between the iron intake and serum iron concentration. Serum zinc concentration was not correlated with hair zinc. Study results revealed that the levels of dietary protein and calcium influence iron and zinc balance in Koreans. This study suggests that dietary recommendations for trace minerals, such as iron and zinc, should be carefully examined. In addition, there is a need to evaluate the bioavailability of milk or beverage products enriched with calcium and iron.

• Journal of Animal Science and Technology
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• v.58 no.5
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• pp.21.1-21.8
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• 2016

Background: The aim of the present study was to determine the effects of feeding trace mineralsfortified mixed microbial culture (TMC) on ruminal fermentation, nutrient digestibility, blood electrolyte status, nitrogen balance, and trace mineral balance in sheep. Methods: Mixed microbes [0.6 % (v/w) of Enterobacter sp., Bacillus sp., Lactobacillus sp., and Saccharomyces sp.] were cultured with 99 % feedstuffs and 0.4 % trace minerals including zinc and copper for ensiling. Six sheep (a mean body weight of $46.5{\pm}1.2kg$) were fed two diets: a control diet (concentrate mix and rye straw) and an experimental diet (a control diet + 3.1 % TMC). Results: TMC feeding did not induce negative effects on ruminal fermentation, nutrient digestibility, blood electrolytes, and nitrogen balance in sheep. Feeding with TMC increased the intake of trace minerals (p < 0.05) and did not affect absorption of trace minerals in the whole digestive tract. Feeding with TMC increased fecal excretion and absorbable intake, and retention of zinc and copper (p < 0.05) by 71 % and 77 %, respectively. Conclusion: Feeding with TMC resulted in higher zinc and copper bioavailability and retention without any adverse effects on sheep performance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.639-647
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• 1992

In this study, the food intake, feces and urine of the seven high school boys were collected and the intake and excretion of protein and zinc were measured. The boys were 16~18 years old and the measurement continued for four weeks during which they maintained their normal living pattern and body weight. Each boy's daily intake and excretion of protein and zinc were measured and apparent digestibility and balance were also studied. The results are as follows. Daily mean intake, fecal loss and apparent digestibility of protein of each boy were $73.89{\pm}1.89g,\;10.86{\pm}0.37g$ and $84.9{\pm}0.5%,$ respectively. The urinary loss of nitrogen was $8.8{\pm}0.2g$ and showed the positive balance of $1.3{\pm}0.3g.$ Daily mean intake, fecal loss and apparent digestibility of zinc of each boy were $14.51{\pm}0.44mg,\;7.82{\pm}0.30mg$ and $43.6{\pm}2.9%,$ respectively. The urinary loss of zinc was $4.96{\pm}0.19mg$ and showed the positive balance of $1.72{\pm}0.58mg.$

• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.292-298
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• 2007

Zinc plays indispensable roles in metabolism, including cell growth, apoptosis, proliferation and differentiation. Kidneys are target organs for various regulators of mineral metabolism, and play a key role in zinc balance. To investigate the zinc uptake efficiency, we examined the zinc uptake and accumulation level in vivo and in vitro study. Plasma zinc concentration was peaked out at 1 hr after oral zinc administration. The renal zinc level was peaked out at 12 hr after oral zinc administration, and it was the highest in 40 mg/kg Zn-Asp administrated group in comparison with other groups. In addition, the m-RNA expression level of zinc transporter-1 (ZnT-1), zinc transporter-2 (ZnT-2) and high-affinity L-aspartate transporter (EAAT-3) in Zn-Asp administered group were increased compared with control groups and $ZnSO_4$ group. In order to investigate the intracellular zinc uptake mechanism, we performed the in vitro study by using human embryonic kidney cell line, HEK 293. Intracellular zinc level was peaked out at 3 hr after zinc treatment. In the same way, the mRNA expression level of ZnT-1 and EAAT-3 were increased compared with control group. This study showed that Zn-Asp is effective the zinc uptake into the kidney by increasing the zinc transporter expression.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1741-1745
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• 2005

Zinc is a trace element that is associated with a stimulation of immune function and regulation of ion balance for livestock production. In this study, the effect of zinc as inhibitor to apoptosis-induced cells was examined in vitro using mammary epithelial cell line, HC11 and macrophage cell line, NCTC3749. Cell viability, measured by MTT assay, indicated that 10 g/ml of zinc had a negative impact on cellular activity and 50 ng/ml was chosen for further testing. Apoptosis was induced in cells treated with C2-ceramide in serum-free media. DNA fragmentation and gene expression of acidic sphingomyelinase (a gene responsible for the progress of apoptosis) were distinctively low in zinc treated cells compared with those in non-treated controls. In conclusion, zinc is involved in the regulation of cell proliferation and apoptosis in mammary epithelial cells and macrophages.

• Resources Recycling
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• v.16 no.6
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• pp.39-45
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• 2007

Optimum condition for neutralization has been studied to remove the copper and zinc ions from spent sulfate solutions which resulted from the acid washing of the base of brass bulb. Chemical distribution of copper and zinc species and the variation of solubility of the two ions with solution pH were obtained by considering the complex formation reaction and mass balance. Removal percentage of zinc was more sensitive to solution pH than that of copper. This results from the fact that the solubility of zinc is higher than that of copper. The form of coagulant affected little the removal percentage of zinc, while addition of coagulant as the phase of solution resulted in higher removal percentage of copper than as the phase of solid.