• Asian-Australasian Journal of Animal Sciences
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• v.18 no.3
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• pp.439-452
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• 2005

Zinc is ubiquitous in all living cells. Structural and catalytic properties of cellular enzymes are zinc dependent. Zinc deficiency leads to a variety of pathological abnormalities with immune impairment. It is an established fact that nutritional status contributes to overall immune response of individuals. Outcome of zinc deficiency on immune system is so drastic that it is difficult to conceive at the first instance. Zinc supplementation has been advocated to prevent diarrheal disease in children with poor nutritional status. The bioavailability of zinc depends upon its sources. Moreover it varies between monogastrics and ruminants. Controversy still prevails between inorganic and organic sources of zinc with respect to their superiority in bioavailability. Zinc exerts immunostimulatory effects in various laboratory and farm animals. Animals having congenital zinc deficiency diseases like A46 lethal trait usually die due to impairment of the immune system unless treated with zinc. The immune mechanism of zinc and its effect on animals and man are discussed. Zinc has been considered as extremely safe at higher therapeutic doses, but does not provide any beneficial effect but rather may cause immunosuppression. More recently, zinc has been prescribed for immunodeficient hosts, to modulate the immune system so that to a certain extent it can combat against opportunistic pathogens.

• 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.64 no.6
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• pp.1092-1104
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• 2022

Using antibiotics as growth promoter has been banned in poultry feed industry, thus various researchers try to seek an alternative to replace the growth-promoting antibiotics. In this study, we aimed to evaluate the growth performance via intestinal nutrient utilization and cecal microbial composition of broiler after dietary supplementation with most commonly using antibiotics, zinc bacitracin, and sophorolipid. A total of 180 1-day-old chicks were randomly assigned, and dietary treatment was as follow: CON, basal diet; ZB, 100 ppm of zinc bacitracin supplemented diet; and SPL, 250 ppm of sophorolipid supplemented diet. Their growth performance was evaluated and the samples of blood, small intestine, and ileal and cecal digesta were collected for biochemical, histological, and genomic analyses. The body weight and average daily gain of 7-day-old chicks were higher in ZB and those in overall experimental period were improved by ZB and SPL supplementation (p < 0.05). Their intestinal characteristics were not affected by dietary treatments in duodenum and ileum. Nonetheless, villus height was increased by SPL supplementation in jejunum (p < 0.05). Moreover, dietary SPL supplementation could down-regulate the expression level of pro-inflammatory cytokine, IL-1β (p < 0.05). mRNA levels of lipid and protein transporters did not differ among the treatments, however, relative expression levels of carbohydrate transporters, GLUT2 and SGLT1 were increased in broiler chicken's jejumum fed zinc bacitracin and sophorolipid supplemented diets (p < 0.05). Dietary zinc bacitracin supplementation could increase the population of Firmicutes in phylum level, and the portion of Turiciacter in genus level. On the other hands, the portion of Faecalibacterium was increased by dietary SPL supplementation compared to the other treatments. Our findings suggest that SPL supplementation improves growth performance through enhanced carbohydrate utilization capacity via improvement of gut morphological status and modulation of the cecal microbial population of broilers.

• Preventive Nutrition and Food Science
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• v.2 no.1
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• pp.42-48
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• 1997

the exocrine pancreatic secretion is an important factor in the maintenance of zinc homeostasis. The daily pancreatic secretion of zinc into the gastrointestinal tract may be two or more times the daily dietary zinc intake. The objective of this study was to examine the distribution of proteins and zinc in pancreatic/biliary fluid following intraperitoneal {TEX}${65}^Zn${/TEX} injection into dietary prepared Sprague-Dawly rats. Distribution of zinc-binding protein in Sephadex G-75 subfractions showed a peak corresponding to the high molecular weight protein standard(<66kDa) in the pancreatic/biliary fluid. Zinc also was associated with the 29~35kDa mole-cular weight proteins. These are similar in size with zinc-containing enzymes, carboxypeptidase A and car-boxypeptidase B. A more remarkable small molecular weight fraction eluted beyond the 6.5kDa standard pro-tein peak. These results show the presence of small molecular weight compound in pancreatic/biliary fluid associated with zinc . These small molecular weight compounds may serve as zinc-binding ligands for the secretion of enogenous zinc into the duodenum. These findings suggest that these lignads may dissociate zinc in the duodenum thus making it vulnerable to complexation with phytate in the upper gastrointestinal tract rendering the zinc unavailable for reabsorption.

• Journal of Nutrition and Health
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• v.33 no.8
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• pp.848-856
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• 2000

The study was designed to assess the zinc nutritional status by gestational age of pregnant women visiting in public health centers in Ulsan. The subjects were divided into 3 trimester by last menstrual period(LMP). Interview for dietary zinc intake and general characteristics of each subjects was given and biochemical analysis of blood and urine was performed. Serum zinc concentration and urinary zinc excretion were analyzed by Flame Atomic Absorption Spectrophotometer, and alkaline phosphatase(ALP) activity was analyzed by Bowers & McComb\\`s method with Schimadzu automatic analyser. Also urinary creatinine was analyzed by Hawk\\`s method. Mean intake of zinc was 6.61${\pm}$1.57mg and did not meet the RDA(44.1% of RDA) for pregnant women by gestational age. Zn intake of 3rd trimester was significantly increased but dietary zinc was almost supplied with cereal and grain (47.30%) which were reported with low zinc availability due to phytate. Mean concentration of serum Zn in 1st trimester was 86.4${\pm}$10.5$\mu\textrm{g}$/dl, was 72.4${\pm}$10.3$\mu\textrm{g}$/dl in trimester and 65.1${\pm}$10.8$\mu\textrm{g}$/dl in 3rd trimester and was declined significantly by gestational age during pregnancy. In was concluded that a decline in serum Zn by gestional age was not influenced by amount of Zn intake. However ALP activity and urinary zinc excretion increased significantly by gestational age. Zinc nutritional status of pregnant women was not confirmed yet due to the physiological changes during pregnancy. However, the pregnant woman may be in a marginal zinc deficient status because of low amount of Zn intake and low bioavailability of Zn from dietary sources. (Korean J Nutrition 33(8) : 848-856, 2000)

• Journal of Nutrition and Health
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• v.43 no.2
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• pp.132-140
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• 2010

High sodium intake is one of the risk factors for the development of hypertension. According to 2007 Korean National Health and Nutrition Examination Survey, sodium intake of Korean was three times higher than adequate intake (1.5 g/day) recommended by Korean Dietary Reference Intakes. High sodium intake is related to high threshold and preference of salty taste. And zinc status is known to affect taste acuity. The hypothesis of this study is that zinc status is associated with salty taste acuity, preference, sodium intake and blood pressure. The subjects included in this study were 50 men and 41 women aged 20-29 y who did not smoke and not take supplements or medications regularly. Dietary intake data for 3 days were collected by 24-h recall for 1 day and dietary record for 2-days. Salty taste acuity and preference were determined by sensory test. Fasting serum concentration of zinc, height, weight, body composition and blood pressure data were collected. Salt taste preference in high zinc intake group ($\geq$ estimated average requirement, EAR; men-8.1 mg/day, women-7 mg/day) was higher than that in low zinc intake group (< EAR). Salty taste preference was inversely correlated with serum zinc concentration in people with low concentration of serum zinc (${\leqq}\;81\;{\mu}g/dL$)(r = -0.3520, p < 0.05). Diastolic blood pressure was higher in high sodium intake group than in low sodium intake group (p < 0.05), positively correlated with salty taste preference (r = 0.3866, p < 0.05) in subjects with daily zinc intake below the EAR. We conclude that low zinc status may be related to high salty taste preference and high blood pressure in Korean young adults.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1174-1178
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• 2009

The purpose of this study was to investigate the effect of dietary zinc levels on carbohydrate metabolism and serum zinc, magnesium and chromium contents in obese rats. Animals were divided into three groups by zinc levels, such as low (15 ppm), adequate (30 ppm) and high (60 ppm) levels of dietary zinc. The food intake, weight gain and feed efficiency ratio were not changed by zinc levels. There were no significant differences in liver, kidney and spleen weights. However, serum glucose concentration significantly decreased as the levels of dietary zinc increased, in particular, that of obese rats fed the high level of zinc was remarkably decreased. Insulin concentration of rats fed high level of zinc diet was significantly higher than that in the other groups. However, there were no significant differences in serum zinc and chromium contents, although serum magnesium fed zinc deficient diet was significantly higher than that of the other two groups. Glucose concentrations had negative correlation with insulin concentrations, and positive correlations with serum magnesium content. In conclusion, serum glucose concentrations were decreased and insulin concentrations were increased as the levels of dietary zinc increased in obese rats. These results suggested that zinc supplement at higher level than adequate one would increase insulin concentration and may improve hyperglycemia problem in obese groups.

• Journal of Nutrition and Health
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• v.36 no.9
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• pp.950-959
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• 2003

To assess zinc status by dietary intake and urinary excretion of preschool children in Busan and to evaluate the relationship of intakes of food and nutrient with urinary zinc excretion, zinc food frequencies of 40 common foods affecting intakes of zinc by food fequency method, nutrient intake by 24hr recall and 24hr urinary zinc excretion were measured with 97 preschool children. The mean zinc intake was 4.29 mg and 43.0% of RDA. The mean zinc intake per 1,000 kcal was 3.09 mg.97.9％ of subjects had zinc intake less than 75％ of RDA. Grains food group was the primary source of zinc intake and supplied 38.9% of the total daily zinc intake. Altogether, plant food products supplied 49.7% of zinc intake. The mean urinary zinc excretion and zinc excretion per gram of creatinine were 0.19 mg and 1.00 mg respectively. The urinary zinc excretion showed positive significant correlations with height and weight (p < 0.05, p < 0.05) , urine volume and urinary creatinine excretion (p < 0.05, p < 0.001) , urinary zinc excretion per creatinine (p < 0.001) , urinary zinc excretion per weight (p < 0.001) , intakes of energy and carbohydrate (p < 0.05, p < 0.01) and usual intake of zinc from eggs food group (p < 0.05) . In conclusion, these results show that the zinc intake of preschool children is low and that sources of dietary zinc are mainly plant foods, suggesting low bioavailability. So nutritional education is needed in order to inc-rease usual intake of animal food group. Interpretation of urinary zinc excretion data is complicated by current uncertainty about "normal" zinc level at this age group. Further studies are needed to obtain extensive data on urinary zinc excretion for this age group.age group.

• Journal of Nutrition and Health
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• v.5 no.2
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• pp.91-103
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• 1972

Zinc is one of the essential trace elements in the living organism for growth and health. The first identified metalloenzyme, carbonic anhydrase, is a zinc compound and several others have been described since. Among zinc deficiency syndromes in animals porcine parakeratosis has been successfully treated with zinc supplements, and in man a syndrome of anemia, hypogonadism, hepatosplenomegaly, and dwarfism, prevalent in parts of Iran and Egypt, has been ascribed to lack of zinc in the diet. Dietary zinc excess in the rat is manifested by a hypochromic, microcytic anemia, poor growth, reduction in liver catalase and cytochrome oxidase. The present study is an attempt to delineate the changes of tissue contents of trace elements, especially of iron, copper and zinc in liver and kidneys of the rats. Weanling albino rats, weighing 60 to 80gm. were used in this experiments. The rats were housed in cages with aluminum floors and received feed and distilled water ad libitum. Animals were divided into three groups, control, low zinc diet and high zinc diet groups. The high zinc diet group was subdivided into 0.5% Zn and 0.7%Zn groups. The supplementary copper or iron was added to the high dietary zinc groups. The animals were sacrificed and the tissues were washed several times with deionized water. The wet digested samples were analyzed by Hitachi Model 207 atomic absorption spectro-photometer for the determination of iron, copper and zinc in the liver and kidney. Hemoglobin level in the blood was measured by cyanmethemoglobin method. The results of this study are as follows: 1) All rats fed high zinc diets and low zinc diets gained less weight than control. Weight gain was not improved by the supplementary copper or iron and both. 2) Hemoglobin concentration was decreased significantly in the rats fed high zinc diets and less in the low zinc diet. Supplementary copper and iron to the higher zinc diet appeared to give some improvement of anemia. 3) The iron contents of the liver and kidneys were significantly decreased in the high zinc groups and the reduction was more significantly in the rats receiving higher zinc diet (0.7%). The supplementary copper caused a further depression of liver iron. On the other hand, the iron, added to the high zinc diet lessoned the severity of the decrease in liver iron and caused kidney iron to be maintained almost at the level found in the rats fed by zinc and supplementary copper diet. 4) High zinc diets did not change copper content of the liver and kidney. Supplementary copper elevated the concentration in the liver and kidney and added iron had no effect on the accumulation of copper in the liver and kidneys. 5) The high zinc diets caused marked increases of zinc content in the liver and kidney. Supplementary iron to the high zinc diet caused increases of zinc contents of liver and kidneys.

• Journal of Nutrition and Health
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• v.38 no.6
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• pp.465-474
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• 2005

The purpose of this study was to investigate the dietary habits, nutritional status, and serum copper and zinc concentrations of adolescent athletes. 50 high school adolescent athletes (29 male, 21 female) took part in physical education high school and 47 high school adolescent non-athletes (21 male, 26 female) in general high school. Questionnaires, anthropometric measurements, 24-hour dietary recalls and blood analysis were conducted. In the males, the mean height, weight and body fat percents of athletes and non-athletes were 174.0/172.9 cm, 67.4/68.3 kg, and 8.9/20.0% (p<0.001) respectively. In the females, the mean height, weight and body fat percents of athletes and non-athletes were 163.7/159.3 cm (p<0.01), 58.7/55.7 kg (p<0.05), and 18.6/30.1 % (p<0.001) respectively. In both male and female athletes, intakes of animal fat were significantly higher and intakes of vitamin C were significantly lower than those of non-athletes. There was no significantly difference in zinc and copper intakes between athlete and non-athlete groups. The average serum zinc level of male athletes was significantly lower than that of male non-athlete. The average serum copper levels of male and female athletes were significantly lower than those of male and female non-athletes. Based on these results, exercise may effect on zinc and copper utilization of adolescent. Further studies on zinc and copper nutrition of adolescent athletes were needed to understand more mineral nutrition and exercise.