• Nutrition Research and Practice
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• v.14 no.4
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• pp.365-373
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• 2020

BACKGROUND/OBJECTIVES: To assess the longitudinal associations of the antioxidant capacity of zinc and body mass index (BMI) with serum uric acid (SUA) in South Korean children. SUBJECTS/METHODS: Using follow-up data from the Ewha Birth and Growth Cohort, we included subjects who were seen at 3 and 7 years of age (n = 183; 90 boys, 93 girls). Daily zinc intake and BMI were assessed at 3 and 7 years of age. SUA measured at 7 years was used as the outcome variable. Using a general linear model, the effects of dietary zinc intake and BMI on SUA were assessed. We also assessed the combined effect of early dietary zinc intake and BMI on SUA in children. RESULTS: The dietary zinc intake at 3 years of age was negatively correlated (ρ = -0.18, P = 0.04), whereas the BMI at 7 years of age was positively correlated (r = 0.18, P = 0.01), with the SUA level at 7 years of age. The dietary zinc intake level at 3 years of age and the BMI level at 7 years of age were, together, significantly related to SUA in children at 7 years of age. SUA was lower in group 1 (normal-weight, high-zinc group) than in the other two groups (group 2: normal-weight, low-zinc and overweight, high-zinc group; and group 3: overweight, low-zinc group). Our results demonstrate the combined effect of zinc intake and BMI on SUA. The combined association remained significant in both the crude and adjusted models (P < 0.01). CONCLUSIONS: SUA was related to combined BMI and dietary zinc intake, and increased zinc intake and normal body weight had a beneficial effect on reducing SUA in children.

• Journal of Nutrition and Health
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• v.39 no.3
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• pp.252-263
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• 2006

Zinc is an antioxidant trace mineral, scavenging free radicals and known to be involved in inflammatory reactions. The prevalence of atherogenic diseases such as coronary heart disease (CHD) are increasing in Korean adults of middle age and elderly. The increased cell damage from free radicals and inflammation have been implicated in etiology of CHD, and the evidence is accumulating that low zinc status is involved in the prevalence of this inflammatory atherogenic disease. However, little is known about the zinc status of Korean CHD and its relationship with dietary zinc intake and zinc bioavailabilty. In this study the serum zinc levels of male patients with CHD over 40 yrs. were compared with that of healthy adult males and its associations with dietary zinc intake and zinc bioavailabilty affecting factors were examined. Serum zinc level was measured by HANARO research reactor using neutron activation analysis (NAA) method. The overall proportion of patients with zinc deficiency, serum zinc concentrations below $74.0{\mu}g/dL$ was 32.8% compared to the 10.3% in healthy group. The average serum zinc levels were $80.7{\mu}g/dL\;and\;88.3{\mu}g/dL$ in patients and healthy group, respectively, showing significantly low zinc status in CHD patients compared to healthy group. The intake of nutrients such as energy, carbohydrate, iron, and copper of CHD patients was significantly higher compared to that of the healthy group. In addition, the intake of calcium, iron, and protein from vegetable foods was significantly higher in CHD patients than that of healthy group. The dietary zinc intake was $12.7{\pm}4.5mg$ and $11.5{\pm}6.9mg$ in CHD patients and control group, respectively, which showed no difference. The phytate intake of patients group, which is 1389.0 mg, was significantly higher than the control group which showed 1104.8 mg. However, the ratio of phytate: zinc or phytate * calcium. zinc per 1000 kcal energy intake did not show any difference between two groups. The serum zinc levels did not show any correlation with zinc or factors that affect the bioavailability of zinc. The dietary factors influencing the zinc status were not found in CHD patients.

• Preventive Nutrition and Food Science
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• v.2 no.1
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• pp.35-41
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• 1997

The pancreas is an important organ in the maintenance of zinc homeostasis. Endogenous zinc is con-tinuously secreted via pancreatic exocrine fluid or to a lesser extent in bile. Much of the endogenous secretion must be reabsorbed to sustain zinc homeostasis. The objective of this study was to estimate the relative size of the pancreatic/biliary zinc pool in comparision to the dietary zinc intake, and to study the effect of the phytate and calcium on the zinc homeostasis using a rat model. At the termination of the experiment, pan-creatic/biliary fluid was collected from the rats. Both radioactivity and total zinc were measured and the relative size of the pancreatic/biliary zinc pool was estimated. To determine the effect of phytate and calcium on zinc homeostsis, dietary zinc intake, the amount of zinc in pancreatic.biliary fluid and fecal zinc excretion were measured. The flow rate of pancreatic/biliary fluid, as corrected for tubing constriction, gives the corrected zinc concentration in the pancreatic/biliary fluid was 2.2 times higher than dietary zinc intake. To maintain zinc homeostasis, zinc absorption/reabsorption was very efficient in the current model; 76%, 88% of absorption/reabsorption for low calcium group and high calcium group 81% for phytate group and non-phytate group, respectively.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.9
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• pp.1348-1354
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• 2008

Two inorganic (zinc sulfate and zinc oxide) and three organic (zinc acetate, zinc-methionine, and zinc-lysine) zinc sources were evaluated for their effects on the performance and carcass characteristics of broiler chicks. The birds were randomly assigned to one control (non-supplemented) and 15 treatment (supplemented) groups consisting of four replicates of 10 chicks each in a $5{\times}3$ factorial arrangement of treatments (five zinc sources and three supplemental zinc levels). Birds were kept in floor pens in a temperature-controlled room from 1 to 42 d of age and fed a non-supplemented basal diet (control) or the basal diet supplemented with 40, 80 or 120 mg/kg of Zn as mentioned sources. Dietary zinc source had considerable effect on feed intake in all experimental periods. Increasing Zn level from 80 to 120 mg/kg decreased the average feed intake in the growth stage (p<0.01) and also in the entire experimental period (p<0.001). Similarly, the average daily gain during the entire trial period was affected by the type of Zn source (p<0.001) and supplemental level (p<0.01). One degree of freedom contrast comparisons showed that the inclusion of organic zinc sources into the diets caused significant increases in feed intake and body gain when compared with inorganic counterparts. Except in wk 1, dietary supplementation with organic sources improved (p<0.05) feed conversion ratio; FCR values were not affected by dietary Zn source or supplementation level. Breast meat yield increased with supplemental levels of organic Zn sources; however, other carcass parameters were not affected by dietary Zn source. On the other hand, organic versus inorganic zinc supplementation caused a significant increase in liver, breast and carcass weight percentages. The present findings suggest that supplemental levels of organic Zn compounds had beneficial effects on broiler performance, and Zn requirements can be reduced using these feed supplements in poultry rations.

• Journal of Nutrition and Health
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• v.33 no.5
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• pp.517-523
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• 2000

The effect of dietary zinc deficiency and age on lipid peroxide level was investigaed in rats. Zinc level in serum and liver were also measured. Fifty Sprague-Dawly male rats aging 8 months(older rats) and 2 months(younger rats) were used as experimental animal. Zinc deficient diet(1.1ppm) and normal zinc diet(36.5ppm) were used as experimental diets. Rats in each age group were divided into zinc deficient(ZnDF), zinc pair-fed(ZnPF) and zinc ad-libitum(ZnAL) to remove the variances of food intake. After 4 weeks of experimetal period, rats were sacrificed. Thiobarbituric acid reactive substance(TBARS) levels in plasma and liver, lipofuscin and conjugated diene levels in liver were measured as lipid peroxide index. Food intakes of all groups were not different because zinc deficiency did not reduce food intake in ZnDF group. Younger rats gained weight continuously, while older rats lost weight in the begining of experiment and regained afterwards. In older rats, serum zinc level was decreaed while plasma TBARS. level was increased in ZnDF group. In younger rats, plasma TBARS concentration was increased in dietary zinc deficient rats although serum zinc concentration was not reduced. Liver zinc concentration was significantly higher in older rats comparing to younger rats. However, there was no difference among the three dietary groups. Liver TBARS level was not different by age or dietary zinc level. However it was tended to be higher in older rats. However there was no difference by the dietary zinc level. In both age groups, ZnDF group significantly increased plasma TBARS levels, which suggested dietary zinc deficiency could increase lipid peroxidation in part. Significantly higher levels of lipofuscin and conjugated diene in older rats suggested lipid peroxidation was accelerated by aging.

• 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)

• Korean Journal of Community Nutrition
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• v.3 no.3
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• pp.389-396
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• 1998

This study was intended to examine the zinc status and effect of zinc supplementation on the zinc nutritional status of the elderly living in the Ulsan area. The zinc intake of 207 subjects(male 97, female 110) was measured by a 24-hour dietary recall and food frequency method. Biochemical analysis were conducted from blood and urine samples to evaluate the changes of zinc nutriture with zinc supplementation. The average dietary zinc intake of subjects was $7.7\pm{2.8mg}$ for male and $7.5\pm{2.6mg}$ for female, which were 51.3% and 62.3% of Korean RDA respectively. The first source of zinc was cereal and grain(36%), and the second was eggs and milk group(27%). After 8 weeks of zinc supplementation, the serum zinc content was significantly increased(p<0.01), although the serum copper content was not significantly decrease. Serum HDL- cholesterol level was not significantly decreased with zinc supplementation. Serum alkaline phosphatase(ALP) activity and urinary zinc excretion were significantly increased(p<0.05). The urinary Zn/Cr was not significantly increased. It is suggested from the results that the daily zinc supplementation can be effective to improve zinc nutriture.

• Journal of Nutrition and Health
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• v.40 no.4
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• pp.385-394
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• 2007

The purpose of this study was to determine the zinc status of preschool children in Ulsan. The study was conducted in 95 children aged 3 to 6 years by investigating the anthropometric indices and assessing the biochemical analysis. The blood was analysed to assess serum zinc and alkaline phosphatase. And a questionnaire for dietary intakes using 24-hr recall method were performed by mothers of 95 subjects. The dietary intakes of children were analysed to determine the prevalence of inadequate and excessive intakes of zinc with Dietary Reference Intakes for Koreans (KDRIs). WHL (Weight-Length Index) and Kaup index were used to define obesity. The overall prevalence of overweight and obese subjects were 14.7% and 6.3% by WHL, were 15.8% and 13.7% by Kaup index. The mean intakes of zinc by children aged 3${\sim}$5y and 6y were 5.5 ${\pm}$ 1.4 mg/d (75.7% RDA) and 6.7 ${\pm}$ 2.0 mg/d, respectively, that was the level exceeding the estimated average requirement (EAR) and the recommended intake (RI) of Korean Dietary Reference Intakes. Less than 1.3% and 7.9% of children had usual zinc intakes below EAR and RI of KDRIs, respectively. The percentages of children with intakes exceeding the tolerable upper intake level (UL) were 2.6%. The zinc nutritional status by biological assay was found that mean serum zinc and alkaline phosphatase (ALP) of total subjects were 64.0 ${\pm}$ 8.4 ${\mu}$g/dl and 72.8 ${\pm}$ 14.9 U/L, there was not a significant difference between boys and girls. The range of serum zinc level was 45${\sim}$89 ${\mu}$g/dl and children with a low serum zinc concentration by several cut-off points were 18.9${\sim}$55.8%, especially. Serum zinc level was positively correlated to the intakes of calorie, calcium, fiber, iron, zinc, zinc/kg and height (p<0.001). Serum ALP was positively correlated height, weight and WLI. The zinc intake of children aiso showed a positive correlation with height and weight. These results indicate that there were significant correlations between the zinc status and growth of preschool children. Preschool children in Ulsan have dietary zinc intakes that exceed the new DRIs. The present level of intake does not seem to pose a health problem, but if zinc intakes with fortified foods and supplements were considered, the amount of zinc consumed by children may become excessive.

• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.79-84
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• 2004

Zinc intake and status of South Koreans from rural, urban and metropolitan areas were investigated. The dietary habits of 760 healthy male and female adult subjects with a mean age of 54 were assessed using a food frequency questionnaire and were verified using 24 h dietary recall. Daily Zn intakes for men and women were 7.4$\pm$5.4 mg and 7.0$\pm$5.4 mg, respectively, which were 62% and 70% of the Korean RDA. The phytate : zinc and phytate ${\times}$ calcium : zinc molar ratios were 38 and 398, respectively. Both the low intake of zinc and the high extremely phytate and phytate ${\times}$ calcium ratios with Zinc suggest that South Koreans may be at risk of zinc deficiency. Plasma zinc (86$\pm$61 $\mu\textrm{g}$/dL), urinary zinc (33$\pm$27 $\mu\textrm{g}$/dL) and plasma alkaline phosphatase (102$\pm$52 mU/mL) levels within the normal range did not however suggest marked Zinc deficiency in these subjects. However, conventional zinc biomarkers aye known to be unreliable for assessment of marginal zinc deficiency. Based on zinc intake alone, it is likely that at least a proportion of these subjects were marginally zinc deficient and the wider consumption of zinc rich, phytate deficient foods, particularly in rural areas, would be beneficial.