• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.713-722
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• 2013

The purpose of this study was to examine the effects of dietary green tea powder supplementation on bone metabolism in streptozotocin-induced diabetic rats. Thirty-two male Sprague-Dawley rats (body weight $210{\pm}3g$) were divided into two groups, diabetic and non-diabetic groups. Each group was randomly divided into two subgroups which were fed with the control and 1% green tea powder diets. The serum and urine concentrations of calcium and phosphorus were determined. Serum osteocalcin and ALP and urinary DPD crosslinks value were measured in order to monitor bone formation and resorption. Bone mineral density (BMD) and bone mineral content (BMC) were estimated using PIXImus in the spine and femur. Body weight gain and FER were lower in the diabetic group than in the non-diabetic group regardless of diets. The serum concentration of calcium and phosphorus were not changed among all groups. Urinary calcium and phosphorus excretion were higher in the diabetic group than in the non-diabetic group regardless of diets; however, they were not significantly different by green tea powder intake. Serum alkaline phosphatase (ALP) was increased in the diabetic group than in thenon-diabetic group. Further, there were no significant differences in serum osteocalcin and urinary deoxypyridinoline crosslinks value among all groups. The levels of spine and femur bone mineral density of the diabetic group were significantly lower than that of the non-diabetic group. Within the diabetic group, spine BMD was significantly higher in rats fed with the green tea powder diet than in rats fed the control diet. Therefore, this study suggests that green tea powder has a beneficial effect on bone health, although it is not directly applicable to humans.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.4
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• pp.530-536
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• 2014

In a $2{\times}2$ factorial experiment the hypotheses tested were that the metabolic acid load caused by benzoic acid (BA) added to the feed affects bone mineralization of weanling pigs, and that a wide dietary calcium (Ca) to phosphorus (P) ratio in phytase-supplemented feeds with a marginal P concentration has a positive effect on bone mineralization. The four experimental diets, which contained 0.4% P and were supplemented with 1,000 FTU phytase/kg, contained either 5 g BA/kg or no BA and either 0.77% Ca or 0.57% Ca. The 68 four-week-old Large White pigs were fed the experimental diets ad libitum for six weeks and were then slaughtered. Benzoic acid increased feed intake (p = 0.009) and growth rate (p = 0.051), but did not influence the feed conversion ratio (p>0.10). Benzoic acid decreased the pH of the urine (p = 0.031), but did not affect breaking strength and mineralization of the tibia (p>0.10). The wide Ca:P ratio decreased feed intake (p = 0.034) and growth rate (p = 0.007) and impaired feed the conversion ratio (p = 0.027), but increased the mineral concentration in the fat-free DM of the tibia (p = 0.013) without influencing its breaking strength (p>0.10). The observed positive effect of the wide Ca:P ratio on bone mineralization may be attributed, at least in part, to the impaired feed conversion ratio, i.e. to the higher feed intake and consequently to the higher mineral intake per kg BW gain. The negative impact on animal performance of the wide dietary Ca:P ratio outweighs its potentially positive effect on bone mineralization, precluding its implementation under practical feeding conditions.

• Journal of Nutrition and Health
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• v.36 no.2
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• pp.175-182
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• 2003

This study was conducted to examine whether bone mineral density changes in 55 young Korean college women aged 19 to 26 years over 2 years and nutritional and biochemical factors are related. Bone mineral density (BMD) was measured in the spine (LS), femoral neck (FN), ward's triangle (WT), and femoral trochanter (FT) by dual energy X-ray absorptiometry three times at one-year intervals. Serum osteocalcin (OC), parathyroid hormone (PTH), and urinary cross-linked N-teleopeptides of type collagen (NTx) were measured. Dietary intake was assessed 8 times with 24-hour recall method. Physical activity (PA) was obtained by questionnaire and body fat content was measured by bioelectrical impedance analysis at baseline and after 2 years. Analyses were performed on 34 subjects with all three BMD measurements. The BMDs at the lumbar spine gradually increased over 2 years, while the BMDs of three sites at the femur were sustained or increased. The mean OC, PTH had a similar pattern with the change of BMD at the femur. The mean NTx decreased over 2 years but was still higher than those in other studies. BMI, body fat, vitamin A and zinc intake had a significant correlation with LS-BMD. Femur, PTH, body fat, vitamin A, vitamin B$_2$and calcium intake had a significant correlation with WT-BMD and was mostly influenced by diet. By multiple regression analysis, it was shown that the significant factors affecting the LS-BMD were BMI and vitamin A intake and those affecting FN and WT were age, BMI, PTH and calcium intake. These results indicate that some Korean women still experience increases in BMD and that this was associated with PTH and vitamin A and calcium intake. Therefore, proper diet and diet management is needed to increase changes in BMD among college women.

• Korean Journal of Community Nutrition
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• v.25 no.4
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• pp.329-339
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• 2020

Objectives: This study was undertaken to evaluate the intake of vitamins and minerals from dietary supplements (DSs) in Korean adults and elderly. Methods: Data for this study was generated from the 2017 Korea National Health and Nutrition Examination Survey (KNHANES). We analyzed 4,204 individuals aged 19 years and older (2,579 users and 1,625 non-users). The survey included 24-h recall questions on food and DS intakes, as well as questions on DS use over the past year. The nutrient DSs evaluated were calcium, phosphorus, iron, vitamin A, thiamin, riboflavin, niacin, and vitamin C. Total nutrient intakes were obtained by combining nutrient intakes of foods and DSs consumed by each subject. Results: Most micronutrient intakes from food (except for thiamin) in adult users, and the four micronutrient intakes (iron, vitamin A, vitamin B₂ and vitamin C) in elderly users, were significantly higher than values obtained in non-users. For total intake of nutrients and DSs, both adult and elderly users had a significantly higher intake than non-users. While proportions below Estimated Average Requirements for all micronutrients by adding respective DSs in users were significantly reduced in adults and elderly as compared to non-users, the proportions of above Tolerable Upper Intake Levels for calcium and vitamin A in adults, and vitamin A in elderly, were significantly increased. In the total subjects examined, consumption of DSs was associated with lower odds ratios of undernutrition of micronutrients, and with higher odds ratios of overnutrition of calcium, iron, and vitamin A, as compared to non-users of DSs. Conclusions: Although DSs consumption by adults and the elderly improves the micronutrient status, it also increases the risk of excessive intake of certain vitamins and minerals.

• Journal of the Korean Dietetic Association
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• v.9 no.2
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• pp.97-105
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• 2003

The purpose of this study was to evaluate nutritional value of traditional fermented foods by dietary intake of university students living in Chungnam. 210 students were asked for their daily food intake using 24-hour recall method for 3 days. And daily nutrient intakes from total foods and fermented foods were analyzed and compared. The mean weight, height, and BMI of the subjects were 67.36㎏, 174.39㎝, 22.15㎏/$m^2$ in men and 53.45㎏, 161.86㎝, 20.40㎏/$m^2$ in women, respectively. The daily intakes of protein, phosphorus, and vitamin B1 were 106.82%, 137.88%, and 108.99% of the Korean RDA. However, the energy, calcium, iron, vitamin A, vitamin B2, niacin, vitamin C intakes did not reached the RDA for Koreans. The fermented food intake was 9.09% of total food intake. And the percentages of fermented food intakes were 81.53% for Kimchi and 14.75% for Chang. The vegetable protein, vegetable oil, dietary fiber, calcium, phosphorus, iron, sodium, potassium, vitamin A, vitamin B1, vitamin B2, niacin and vitamin C intakes per 1000㎉ consumption from fermented foods were significantly higher than those from total foods. The fermented food intake showed positive correlation with iron, and plant iron intakes. In conclusion, the percentage of fermented food intake was about 9% and the major items were Kimchi and alcoholi beverages in university students. Fermented food intake may be important to improve the intakes of calcium, iron and vitamin.

• Korean Journal of Community Nutrition
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• v.8 no.2
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• pp.149-159
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• 2003

The purpose of this study was to develop and evaluate the validity of a food frequency questionnaire for Korean adolescents (FFQ-A) which could be used in clinical and epidemiological studies of the lifestyle and health of young people. The FFQ-A was designed to reflect the eating pattern of Korean adolescents, and was based on the 1998 Korean National Health and Nutrition Survey Reports. The FFQ-A had 25 (food categories. A total of 125 subjects (aged 13 to 15 years) was recruited from a randomly chosen middle school in a middle-income neighborhood in Anyang, South Korea. Each subject completed a FFQ-A, as well as a three-day dietary record. Data from 117 subjects (boys 47, girls 70) was used in the final analyses. Data on the nutrients was analyzed to estimate the Pearson correlations, Spearman rank-order correlations and agreement with categories. The validity of the FFQ-A was assessed relative to a three-day dietary record. The Pearson correlation coefficients for all the subjects were 0.94, 0.87, 0.77, 0.79, 0.49 and 0.68 for energy, carbohydrate, protein, fat, calcium, and iron, respectively. Similarly the Spearman rank-order correlation coefficients were 0.94, 0.85, 0.79, 0.81, 0.46, and 0.77 for energy, carbohydrate, protein, fat, calcium and iron, respectively. The Kappa values for energy, carbohydrate, protein, fat, calcium, and iron were 0.88, 0.67, 0.63, 0.67, 0.26, and 0.59, respectively. The percentage for misclassification of the lowest quartile into the highest quartile or vice versa ranged from 0% (energy, carbohydrate, or fat) to 16.7% (Vitamin C). Therefore the FFQ-A has a reasonable ability to assess the energy, carbohydrate, protein and fat intakes as estimated from a three-day dietary record of Korean adolescents. (Korean J Community Nutrition 8(2) : 142∼159, 2003)

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.89-112
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• 2022

An accurate assessment of the recommended calcium (Ca) intake may contribute to reducing the risk of fractures and chronic diseases, ultimately improving quality of life. This review was performed to summarize key findings of Ca studies, investigate the effect of Ca intake on health outcomes, and determine the adequacy of evidence to revise the 2015 Dietary Reference Intakes for Koreans (KDRIs) for Ca in 2020. Databases were searched for intervention studies that assessed health outcomes by providing Ca in diets or as supplements. The framework of the systematic review comprised conducting literature searches, data extraction, quality assessment of the literature, and summarizing key findings relevant to set the Estimated Average Requirement (EAR) and Tolerable Upper Intake Level (UL) for Ca for the 2020 KDRI. The final search was performed in June 2019. A total of 13,309 studies were identified through databases and manual search. Sixtyfive studies were included in the final quality assessment and were summarized according to health indicators. As bone health was used as an indicator of the EAR for Ca, literature reports on bone health were further categorized by the life-cycle stage of the participants. This systematic review did not find new evidence that could be applied to the general Korean adult population, including postmenopausal women, for defining a new EAR for Ca in the 2020 KDRIs. Evidence in most of the reviewed literature was considered weak; however, some evidence was found that could improve the criteria on how the EAR for Ca was determined in children and adolescents. A review of the literature for the 2020 KDRIs for Ca did not find strong evidence in order to change the recommended values of the 2015 KDRIs. More clinical interventions are required among Koreans to strengthen the body of evidence to warrant the revision of the KDRIs.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.174-184
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• 2011

The purpose of this study was to evaluate nutrients intakes, glycemic index (GI), glycemic load (GL) according to obesity index in elementary school students. The study subjects included 229 elementary school students (boys=108, girls=121) who were divided into 3 groups consisting of an underweight group (obesity index<-10%, n=58), a normal weight group (10%${\leq}$ obesity index<10%, n=130) and an overweight group (obesity index${\geq}$10%, n=41) by their obesity index. The nutrient and food intakes data obtained by a 3-day food record were analyzed. Daily dietary GI and GL values were calculated from the 3-day food record. The average age of the subjects was 11.9 years. The mean daily energy intake was 2,186.8 kcal in the underweight group, 2,123.5 kcal in the normal weight group, and 2,174.2 kcal in the overweight group. The intakes of calcium and animal calcium per 1,000 kcal in the overweight group were significantly lower than in the underweight and normal weight groups (p<0.01, p<0.05), and fruit, egg and milk intakes in the overweight group were lower than those in the underweight group (p<0.05, p<0.05, p<0.05). The mean daily dietary GI of the underweight, normal weight, and overweight groups were 67.7, 68.4 and 69.5, respectively (p<0.05). The mean daily dietary GL of the underweight, normal weight, and overweight groups were 212.8, 208.1 and 213.3, respectively. The major food source of dietary GI and GL in the three groups was rice. Other major food sources of dietary GI were croquettes, hand-rolled noddle soups, instant noddles, milk, and rice cake. Dietary GI was not significantly correlated with weight, obesity or body mass index, when adjusted for energy, carbohydrate, and dietary fiber. However, GL adjusted to energy, carbohydrate and dietary fiber tended to correlate with obesity index (r=0.126, p=0.059). These results suggest that dietary GI and GL have possibility affecting obesity-related indicators in elementary school students.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.48-54
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• 2006

This study was conducted to investigate the effect of calcium and boron intakes on calcium utilization in ovariectomized (OVX) rats. Rats were divided into 9 groups and fed diets containing various levels of calcium $(0.1\%,\;0.5\%,\;1.5\%)$ and boron (0.5 ppm, 50 ppm, 100 ppm) for 4 weeks. The half of rats in each group were ovariectomized and the others were sham-operated. Rats were fed same diets for 8 weeks after operation. Feed intake and weight gain were significantly increased as the dietary calcium was increased and those of OVX group were higher than in sham-operated group. Feed efficiency ratio was significantly higher in OVX group than that in sham-operated one. With boron supplementation, serum calcium level was significantly increased in low-calcium group, but decreased in adequate/high-calcium group. In calcium balance, calcium intake was significantly increased with increasing levels of calcium and boron and higher in OVX group than that in sham-operated one. With increasing calcium intake, fecal and urinary calcium excretions were significantly increased. Urinary calcium excretion was significantly decreased with increment of boron intake. Apparent calcium absorption of adequate-calcium OVX group was the highest among the groups. Daily calcium retention was significantly increased as the dietary calcium was increased and that of high-calcium OVX group was higher than high-calcium sham-operated group. According to these results, the boron supplementation increased the calcium intake and decreased the urinary calcium excretion. Therefore, it could be suggested that the boron supplementation may be complementary to calcium nutrition and useful for bone health.

• Journal of Nutrition and Health
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• v.35 no.8
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• pp.840-847
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• 2002

This study explored the effect of dietary levels of Na and Ca on spontaneously hypertensive rats (SHR). SHR were randomly divided into 5 groups and fed a high fat/cholesterol diet containing three levels of Na (0.05, 0.1, 1.5%) and Ca (0.1, 0.5, 1.5%) for 9 weeks. Body weight gain was not influenced by dietary intake but water intake significantly increased in high Na supplementation. Systolic blood pressure was not influenced by dietary Na and Ca levels but was decreased by dietary low Na/high Ca levels at 9 weeks. Angiotensin-II level was affected by dietary Na level but not by Ca levels. Plasma Ca, Mg, K and Na levels were in the normal range regardless of dietary Na and Ca levels. Weight, and K and Na contents of the heart and kidney were not significantly different among those with different dietary Na and Ca levels. Ca and Mg contents of the heart and kidney were significantly higher in the normal Na/normal Ca group. Ca and Mg in the feces were higher in those with high Ca intake. Na in the feces was higher in those with high Na intake. Therefore, Na and Ca had different mechanisms in the hypertension/hyperlipidemia models, respectively. And we suggested that Mg must be supplemented when Ca intake was high because Mg excretion was increased by Ca supplementation.