• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.1
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• pp.87-94
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• 2012

We evaluated the bioavailability of a novel organic Ca supplement chelated with milk protein (CaMP) in growing rats and compared it with those of Ca carbonate and Ca citrate. Four-week-old male rats were divided into six groups (n=6/group) and fed AIN-93G-based experimental diets containing three Ca sources, Ca carbonate, Ca citrate, and CaMP at two levels, normal (0.5%, w/w) and high (1.5%, w/w), for 6 weeks. Growth, mineral contents of serum, Ca content and breaking force of femur, and Ca absorption were measured. There were no significant differences in weight gain or food intake, but food efficiency ratio (FER) of CaMP in the high Ca group was higher than those of other groups. Ca and P concentrations in serum were within normal range in all experimental rats. There was no difference in Ca content of the femur among all of the groups. Although there was no statistical significance in bone breaking force of the femur among the groups, the CaMP groups had a higher breaking force compared to other groups. Further, Ca absorption rate significantly increased in the CaMP groups (p<0.05). These results demonstrate that the CaMP supplement did not exhibit any negative effect on growth or Ca metabolism of the rats. Therefore, CaMP can be recommended as a good Ca supplement with regard to bone metabolism and Ca bioavailability.

• Journal of Nutrition and Health
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• v.37 no.6
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• pp.423-430
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• 2004

This study was performed to evaluate the effect of red-yeast-rice on bone metabolism in overiectomized (OVX) rats. Forty female Sprague-Dawley rats (body weight 210 $\pm$ 5 g, 9 weeks old age) were divided into two groups. One group were OVX, and the other group received sham operation (SHAM), and received either control diet (20％ casein) or a red-yeast-rice power supplemented diet (0.1％) for 9 weeks. And then each rat group was further divided into control diet (casein 20％) and red-yeast-rice powder supplemented (0.1％) diet group. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone mineral density (BMD) and bone mineral content (BMC) were measured using PIXImus (GE Lunar Co, Wisconsin, USA) in spine and femur on 5, 9 weeks after feeding. The serum and urine concentrations of Ca and P were determined. Bone formation was measured by serum osteocalcin and alkaline phosphatase (ALP) concentrations. And bone resorption rate was measured by deoxypyridinoline (DPD) crosslinks immunoassay and corrected for creatinine. Serum osteocalcin, growth hormone, IGF-l and calcitonin were analyzed using radioimmunoassay kits. Urinary Ca and P excretion were not significantly different among the groups. Within the OVX group, the red-yeast-rice group had a lower crosslinks value than the casein group. Therefore the red-yeast-rice supplemented groups had a lower bone resorption ratio than the casein group in the ovariectomized rats. And, the red-yeast-rice group had significantly higher IGF-l hormone than casein group in ovariectomized rats. The red-yeast-rice group had higher spine bone mineral content than those of control group within the OVX groups. This study was an important first step in establishing that the observed beneficial effects of red-yeast-rice on bone, and this study also established the need for a study on the long-term effect of this supplement in a human.

• Journal of Nutrition and Health
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• v.36 no.2
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• pp.154-166
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• 2003

To investigate the effects of isoflavone supplementation on both bone mineral density and hormone variation in premenopausal women who had decreased bone mass, the 24 subjects were divided into two groups: one was the underweight group, consisting of 13 subjects, and the other was the normal weight group consisting of 11 subjects. For each group, we investigated the effects of isoflavone supplementation of 90 mg/day on both bone mineral density and hormone variation during 3 menstrual cycles. Anthropometric measurements, dietary recall, and analyses of blood and urine were assessed from baseline to post-treatment. The results were as follows: The average age of the underweight group was 21.8 years old and that of the normal weight group was 23.2 years old. The comparative results for the two groups at baseline were as follows: Onset of menarche, menstrual cycle, and menstrual length were not significantly different between the groups. Serum protein, total, HDL-, LDL-cholesterol, triglyceride, Ca, P, Mg, Cu, and Zn level were not significantly different between the groups. Serum estradiol, SHBG, LH, and FSH level were also not significantly different between the groups. Lumbar spine BMD by T scores of the underweight group was significantly lower than that of the normal weight group. Serum osteocalcin, urinary DPD, and urinary pH were not significantly different between the groups. The comparative results for the two groups at post-treatment were as follows: From baseline to post-treatment, the intake of energy, nutrients and isoflavone in food did not significantly change in either group. Serum protein, total cholesterol, HDL-, LDL-cholesterol, and triglyceride levels did not significantly change in either group. Serum Ca, Cu, and Zn levels were significantly lower in both groups and serum Mg level significantly decreased only in the underweight group. Serum estradiol levels were significantly lower in both groups, but serum SHBG, LH, and FSH levels did not significantly change in either group. Lumbar spine BMD by T score of the underweight group significantly increased to 15%, but that of the normal weight group did not significantly change. Serum osteocalcin of the underweight group significantly increased to 28%, while that of the normal weight group significantly increased to 40%. Urinary DPD of the normal weight group significantly increased to 12%. The results show that the BMD of the underweight group was lower than that of the normal weight group. Therefore, the underweight group had a disadvantage in obtaining maximum bone mineral density. The results also show that isoflavone supplementation during 3 menstrual cycles was effective in increasing the bone mineral density of the lumbar spine and affected bone metabolism markers in premenopausal underweight women. Therefore, it can be concluded that sufficient intake of isoflavone could be helpful in preventing decreases in bone mass among premenopausal women, especially underweight women.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1560-1567
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• 2008

This study was designed to evaluate the effect of green tea products (GTP) on bone metabolism marker in ovariectomized (OVX) rats fed high cholesterol diet. Forty Sprague-Dawley female rats, 10 weeks of age ($279{\pm}2g$), were divided into 4 groups and fed on the experimental diets for 6 weeks: sham operated control (Sham-C) and OVX-control (OVX-C) groups treated high cholesterol diet. OVX-GTP 5% (OVX-G5) and OVX-GTP 20% (OVX-G20) groups were treated with high cholesterol diet containing 5% GTP and 20% GTP, respectively. Food efficient ratio was significantly (p<0.05) lower in OVX-G20 than in the other OVX groups. Bone mineral density of femur was not significantly different among the experimental groups in the order of Sham-C>OVX-G5 and OVX-G20>OVX-C. Alkaline phosphatase activities on serum was lower in the GTP supplement groups than in the OVX-C. Estradiol levels of serum were higher in the GTP supplement groups than in the OVX-C. Osteocalcin levels of serum was the lowest in the OVX-G20. Deoxypyridinoline crosslink values of urine, indicator of bone absorption, was the lowest in the OVX-G20 group. The GTP supplemented groups had a lower bone resorption ratio than in the OVX-C group. From the above results, these findings suggest the possibility of using GTP as a functional food materials related to bone metabolism in menopause.

• The Korean Journal of Nuclear Medicine
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• v.2 no.1
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• pp.49-52
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• 1968

The influence of estradiol on the radioactive calcium metabolism in blood, bone and young of lactating rats has been studied. Estrogen, in an amount estimated to equal that secreted in late pregnancy, was injected daily into lactating rats for 4 days along with $^{45}Ca$. On the 5th day, radioactivity of blood serum, bone, and young was compared to a similar group of lactating rats not treated with estrogen. Average gain in weight of the litters of the 2 groups was similar. However, radioactivity in serum and bones of treated with estradiol was significantly higher than in the controls. The radioactivity in litters of the 2 groups was similar. Estrogen plays a role in the retention of calcium in the animal body.

• Journal of Nutrition and Health
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• v.25 no.2
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• pp.132-139
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• 1992

A study was conducted to compare urinary Ca excretion and factors influencing urinary Ca excretion in 30 young and 62 middle-aged Korean women. Mean daily intake levels of total protein and P were significantly higher in middle-aged women but Ca and animal protein intake levels of the two groups were similar. The average percentage of daily Ca intake from milk and milk products in young women was 45% while in middle-aged women it was about 24% The frequency of milk consumption was inversely correlated with blood pressures of the subjects. Mean 24-hour urinary calcium excretion in young and middle-aged women were 163.7mg and 174.9mg respectively. The difference was not significant. Menopause of the mid-dle-aged women did not affect urinary calcium levels. However the proportion of subjects with more than 250mg of Ca in 24-hour urine tended to be higher in middle-aged group Factors significnatly correlated with urinary Ca excretion of subjects were systolic and diastolic The study verifies the need for more systematic studies on Ca requirements and the interrelation-ship among Ca and na metabolism blood pressures and bone loss in the middle-aged Korean.

• Journal of Nutrition and Health
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• v.34 no.8
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• pp.887-895
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• 2001

This study was designed to investigate the effect of dietary boron supplementation and calcium levels on calcium and bone metabolism in ovariectomized female rats. The experimental group classified ovariectomized group(O) and sham operation group (S). The two groups were then each randomly divided into flour sub-groups and fed experimental diets consisting in two levels of calcium and at each level of calcium, there were boron supplemented group and non-supplemented group. Calcium levels were either 0.2%(low calcium group: L) or 1.2%(high calcium group: H). The level of boron in the diet for the boron supplemented groups(B) was 100$\mu\textrm{g}$/g diet. The experimental period was six weeks. The average food intake were not statistically significantly different in all of eight groups. The increase in weights of rats was observed only in ovariectonized and sham control rats(low ca without boron supplemented). The rest of the groups lost weight significantly during the experimental period ranging from 26.94g to 44.34g. Significant higher calcium intakes were observed in high calcium groups, regardless of boron supplementation during experimental period. Urinary calcium excretion was not affected either by ovariectomy or diets on the first, third and sixth week of feeding. Apparent calcium absorption rates were not different among the groups on first week, whereas noticeable increase was observed in low calcium groups at third and sixth weeks. Femur wet and dry weight, and calcium contents of femur were higher in low calcium groups. whereas femur bone density was higher low calcium with boron supplementation groups than low calcium groups. Scapular density did not show any significant differences among all groups. Despite there were no differences in the activities of alkaline phosphatase by boron supplementation, boron supplemetation appeared to cause higher femur density. There results suggest that in both of sham-operated and ovariectomized rats low calcium did not influence greatly bone status of rats and boron increased bone density.

• Journal of Biosystems Engineering
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• v.37 no.4
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• pp.258-264
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• 2012

Purpose: This review aims at introducing 3 modeling approaches classified into 3 categories based on the purpose (estimation or prediction), structure (linear or non-linear) and phase (steady-state or dynamic-state); 1) statistical approaches, 2) kinetic modeling and 3) mechanistic modeling. We hope that this review can be a useful guide in the model-based approach of calcium metabolism as well as illustrates an application of engineering tools in studying biosystems. Background: The meaning of biosystems has been expanded, including agricultural/food system as well as biological systems like genes, cells and metabolisms. This expansion has required a useful tool for assessing the biosystems and modeling has arisen as a method that satisfies the current inquiry. To suit for the flow of the era, examining the system which is a little bit far from the traditional biosystems may be interesting issue, which can enlarge our insights and provide new ideas for prospective biosystem-researches. Herein, calcium metabolic models reviewed as an example of application of modeling approaches into the biosystems. Review: Calcium is an essential nutrient widely involved in animal and human metabolism including bone mineralization and signaling pathways. For this reason, the calcium metabolic system has been studied in various research fields of academia and industries. To study calcium metabolism, model-based system analyses have been utilized according to the purpose, subject characteristics, metabolic sites of interest, and experimental design. Either individual metabolic pathways or a whole homeostasis has been modeled in a number of studies.

• Korean Journal of Community Nutrition
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• v.16 no.5
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• pp.569-579
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• 2011

The purpose of this study was to determine the urinary Ca, P, Mg, Zn, Cu, and Mn levels and bone mineral density (BMD) in sixty-two postmenopausal women. The study was conducted through anthropometric checkup, 24-hour recall, 24-hour urine and bone mineral density using DEXA. Average age, height, weight and body fat of the subjects were respectively 65.39 years, 150.19 cm, 58.03 kg and 37.22%. The average spine and femoral neck BMD of subjects were -2.19, -3.13. The mean intakes of Ca, P and Mg were 524.7 mg, 993.10 mg, and 254.6 mg and those of Zn, Cu and Mn were 8.6 mg, 1.5 mg, and 3.5 mg. The average 24-hour urinary excretion of Ca (UCa), P (UP) and Mg (UMg) were 161.07 mg, 673.68 mg, and 99.87 mg. The average 24-hour urinary excretion of Zn (UZn), Cu (UCu) and Mn (UMn) were 366.50 ${\mu}g$, 22.57 ${\mu}g$, and 1.55 ${\mu}g$. Ca intake showed significantly positive correlations with urinary UCa (p < 0.05), UMg (p < 0.01) and spine BMD (p < 0.05). P intake showed significantly positive correlations with UCa (p < 0.05), UMg (p < 0.05) and UZn (p < 0.05). Mg intake showed significantly positive correlations with UZn (p < 0.05) and Mn intake showed significantly positive correlations with UCa (p < 0.05). Multiple regression analysis indicates that Ca intake and UMg is the most important factor to increase spine BMD. On the other hand, UCa is the most important factor to decrease spine BMD. Higher femoral neck BMD was related to UP, while lower femoral neck BMD was related to UCa. In conclusion, Dietary intake of Ca showed positive effect of spine BMD, while excessive P intake showed negative effect on BMD due to increases in UCa, UMg and UZn. Further studies are required to investigate the relationship between bone metabolism and mineral excretion.

• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.45-52
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• 2004

Effects of dietary calcium lactate (CaL-A) and Chungkukjang (Korean native fermented soybean) on bone mass, calcium status, body weight, serum glucose and cholesterol levels in young male rats were investigated. Chungkukjang was fermented by mixing 4 types of Bacillus sp., and then dried at 45$^{\circ}C$. Calcium lactate was prepared from the ash of black snail. The rats were fed a commercial rat diet for 1 week and then the experimental diets for 4 weeks. Animals were divided into four dietary groups: one calcium-deficient diet (Ca-De) and one of three with calcium supplemented diets (5 g calcium/kg diet) with either calcium phosphate (Ca-P), CaL-A, or CaL-A + Chuntkukjang (CaL-AC). Calcium supplemented diets contained 39 g Ca-P/kg diet and 28 g/kg of calcium lactate in the CaL-A and CaL-AC diets. Body weight gains during the 4 weeks in the Ca-P, CaL-A, CaL-AC and Ca-De groups were 130.45 g,112.50 g, 143.40 g and 10.20 g, respectively. Feed consumption of the groups from high to low was CaL-AC > Ca-P > CaL-A > Ca-De. The Ca-De group had low femur weights and low serum calcium concentrations, while they were comparatively high in CaL-AC, Ca-P and CaL-A groups. The Ca-De groups excreted less calcium in urine than did the other rats, probably due to increased absorption of the mineral in Ca-P, CaL-A and CaL-AC groups. Microscopic observations revealed that there were many regularly spaced holes in the femur of Ca-De group, while there were much smaller regularly spaced holes in Ca-P group. However, no holes in femur were observed in the CaL-A and CaL-AC groups. Bone surfaces were especially smooth and clean in the CaL-AC group. Serum concentrations of glucose and total cholesterol were remarkably lower in the CaL-AC group than in the other supplemented groups. These results suggest that calcium from CaL-A has higher bioavailability than from Ca-P, and dietary Chungkukjang may have a beneficial effect on calcium metabolism.