• Korean Journal of Exercise Nutrition
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• v.24 no.4
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• pp.24-27
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• 2020

[Purpose] Dehydroepiandrosterone (DHEA) administration reportedly recovers osteoporosis, a bone disorder associated with bone deficiency in postmenopausal women. However, the physiological mechanism of DHEA in osteoporosis remains elusive, especially in terms of intestinal calcium absorption. Therefore, we investigated the effect of DHEA administration on calcium absorption in ovariectomized (OVX) female rats using an estrogen receptor antagonist. [Methods] Female Sprague-Dawley rats (n=23, 6 weeks old) were randomized into three groups: OVX control group (OC, n=7), OVX with DHEA treatment group (OD, n=8), and OVX with DHEA inhibitor group (ODI, n=8) for 8 weeks. [Results] Intestinal calcium accumulation, as well as the rate of absorption, demonstrated no significant differences during the experimental period among investigated groups. The bone mineral density (BMD) of the tibia at the proximal metaphysis was higher in the OD group than that in the OC group (p<0.05); however, BMD of the ODI group showed no significant difference from investigated groups. Furthermore, the BMD of the tibia at the diaphysis did not significantly differ among these groups. [Conclusion] We revealed that DHEA administration does not involve intestinal Ca absorption, although this treatment improves BMD levels in OVX rats. These observations indicate that the effect of DHEA on the bone in postmenopausal women is solely due to its influence on bone metabolism and not intestinal calcium absorption.

• 한국노년학
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• v.31 no.2
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• pp.303-315
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• 2011

The purpose of this study was to investigate effect of resistance training on BMD and bone metabolism related markers in aging rats. Thirty male Spraugue-Daweley rats were divided into sedentary (CON; n=10 ) non-load resistance trained(NLRTG; n=10), and load resistance trained(LRTG; n=10) groups at the age of 64 weeks. The rats in the resistance training groups((NLRTG and LRTG) performed the tower climbing exercise 4 times a week. The LRTG groups were conditioned to climb a vertical ladder with weights appended to their tail 4 days/wk for 12 wks. After 12 weeks of exercise, serum osteocalcin, bone mineral density (BMD), breaking force, ash, Ca, and P in the femur were measured. After training, serum osteocalcin (OC) was significantly (p < 0.05) higher in both LRTG and NLRTG when compared to Control. Right femur BMD was significantly (p < 0.05) greater for LRTG when compared to both NLRTG and Control with no significant difference between NLRTG and Conrtol. The breaking force of femur was significantly (p < 0.05) greater for LRTG and NLRTG when compared to Control. The Ash, Ca, content of femur were significantly increased in resistance training groups than control group. These results suggest that the increase in bone mineral density induced by resistance training is mediated by changes in bone microarchitecture as well as training intensity and osteocalcin.

• Korean Journal of Community Nutrition
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• v.10 no.4
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• pp.536-545
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• 2005

This study was conducted to investigate osteopenia and osteoporosis prevalence of radius and tibia using Quantitative Ultrasound (QUS) and to identify affecting factors of osteoporosis. A total of 4,340 women aged 40 - 69 years, living in Ansung (rural) and Ansan (mid-sized) area, and free of illnesses affecting bone metabolism participated in the community-based cohort study. Among them 4,059 subjects measured radius bone density and 4,089 measured tibia. The T-score threshold, defined as < -1.0 and $\le$-2.5, was used to identify subjects with osteopenia and osteoporosis by WHO criteria. The crude prevalence of osteoporosis in radius and tibia was $8.4\%$ and $23.3\%$ respectively; after adjustment for age, it changed $6.3\%$ and $18.8\%$. In simple logistic regression analysis, the prevalence of osteoporosis increased by aging, non-marital status, low education, low income. Otherwise, high intakes of Ca/P, thiamin, riboflavin, vitamin B6, and vitamin E were decreased osteoporosis prevalence. Compared to the normal BMI (body mass index) group 08.5 $\le$ BMI < 23), the odds ratio (ORs) of the low BMI group (BMI < 18.5), and high BMI groups (BMl25-30, BMI $\ge$ 30) were significantly increased. The OR of osteoporosis decreased across increasing quartiles of intakes of Ca, P and Ca/P. Therefore, maintaining normal BMI and increasing Ca intake and Ca/P ratio may have a beneficial effect on bone health of Korean women.

• The Korean Journal of Community Living Science
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• v.16 no.1
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• pp.135-148
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• 2005

This study was conducted to investigate the bioavailability of calcium derived from starfish as a new calcium source. Four-week old Sprague-Dawley female rats were divided 6 groups. The rats were received experimental diets containing two kinds of Ca sources, CaCO₃ or starfish, and three levels of Ca, low (0.1 %), medium (0.5%) and high (1.0%), respectively, for 6 weeks. The parameters which related to Ca bioavailability were measured : Serum Ca concentration, Alkaline phosphatase(ALP) and GOT activities ; tissue Ca contents, bone dimension and Ca, P, Mg contents; Ca retention and apparent absorption. Starfish Ca-fed rats did not show any difference from CaCO₃-fed rats in terms of growth, food intake and FER. Serum Ca, ALP and GOT activities as well as tissue Ca contents were not different between CaCO₃- and starfish Ca-fed groups. Although dimension of femur and lumbar was not different between CaCO₃- and starfish Ca-fed rats, ash content was high in starfish Ca-fed rats. Ca and P contents of femur and lumbar were not different between both groups. Starfish Ca-fed groups showed higher Mg contents than CaCO₃-fed groups in both femur and lumbar. Ca absorption rate and retention rate were significantly higher in starfish Ca-fed rats. These results indicate that Ca derived starfish did not show any negative effect on growth and Ca metabolism of rats compared to calcium carbonate. Starfish Ca can be recommended as a good Ca source on the basis of higher Ca absorption and bioavailability.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.1
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• pp.37-49
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• 2015

During pregnancy, the maternal body undergoes significant physiological changes. The present study assessed the changes on calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na) and potassium (K) metabolism in singleton and twin-pregnant dairy goats. The 42 goats used ($49.5kg{\pm}7.6$ body weight [BW]) were assigned at random to treatments that were factorially arranged to account for 2 breeds (Oberhasli and Saanen), 2 pregnancy types (singleton and twin) and 3 gestation periods (80, 110, and 140 days). Digestibility trials were performed at 80, 110, and 140 days of gestation. Mineral retention during pregnancy was determined in the maternal body, femur, uterus, mammary gland, fetus and fetal fluid. Blood samples were taken during pregnancy before and after a meal, and Ca, P, Mg, Na, K ions and alkaline phosphatase activity determined in serum. Bone mineral density was determined in the right femur. Statistical analyses were performed using the SAS MIXED procedure. Dry matter intake decreased linearly up to 140 days of gestation. Maternal BW gain, and Ca, P, and Mg retention (g/kg) decreased linearly with the advance of gestation days. Macromineral retention in maternal body (g/kg) was greater in Oberhasli than Saanen goats, and their fetuses had higher Ca, P, and Mg deposition (mg/g). Mineral retention (mg/g) increased in fetuses according to pregnancy development, with no differences between singleton and twin pregnancy. In the mammary gland, the retention of all minerals (g) increased with the days of pregnancy. In conclusion, related to Ca, P, and Mg metabolism can be divided into two stages. Up to 80 days of gestation, was characterized by the preparation of the maternal body reserves for future mineral demands. From 80 days of gestation onward, was characterized by the transfer of maternal body reserves for fetal development and colostrum production. Na and K supply was provided by adjustments in endogenous excretion and an increase in intestinal absorption. Finally, mineral metabolism was specific to each genotype and, except for Na, was not affected by the number of fetuses.

• Journal of Nutrition and Health
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• v.45 no.2
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• pp.121-126
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• 2012

This study evaluated the effect of fish oil rich in n-3 fatty acids on bone characteristics in Sprague-Dawley rats. Weanling male rats were randomized to receive either a diet containing high fish oil (FO), fish oil blended with corn oil (FICO), or soy oil rich in n-6 fatty acids (SO) for 4 weeks. All diets provided 70 g/kg fat based on the AIN-93G diet. Growth and biomarkers of bone metabolism were analyzed, and femur bone characteristics were measured by dual-energy X-ray absorptiometry. After the dietary treatment, no significant differences among the diet groups were observed for serum concentrations of Ca, parathyroid hormone, calcitonin, or osteocalcin. Alkaline phosphatase activity was significantly greater in FO-fed rats compared to that in the FICO and SO groups, whereas no difference in deoxypyridinoline values was observed, supporting the positive effect of a FO diet on bone formation. These results were accompanied by a significant increase in femur bone mineral density (BMD) in FO-fed rats. These findings suggest that providing fish oil rich in n-3 fatty acids correlates with higher alkaline phosphatase activity and BMD values, favoring bone formation in growing rats.

• Journal of Nutrition and Health
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• v.31 no.9
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• pp.1446-1456
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• 1998

Bones are important parts in sustaining the shape of the body, but they are also metabolic organs which undergo bone remodeling by constant bone resorption and formation. Osteoporosis, the typical metabolic bone disease, is characterized by a reduction in bone mineral density (BMD). Women more than men are at risk fir osteoporosis-related fractures, especially in the lumbar spine, wrist, and hip region. Risk of fracture depends on one's BMD, which open determined by the peak bone mass value achieved at skeletal maturity and followed by subsequent age-and menopause-related bone loss. Genetic and environmental factors are known to play a key role in bone metabolism and diet is considered as one of the important environmental factors. The purpose of the present study was to assess the status of BMD and bone mineral content(BMC) to clarify the relationships between dietary intakes and the risk of osteoporosis in adult women in Taegu. Subjects were 130 healthy females in between 20 and 69 years of age. BMD and BMC of the lumbar spine(venebrae L2-4) of the subjects were measured by dual energy X-ray absorptiometry. The average age of the subjects was 47.4${\pm}$11.7 years old, the average weight was 57.2${\pm}$8.4kg, the average age of menarche was 16.6${\pm}$1.9 years old and the average age of menopause was 48.4${\pm}$5.3 years old. The nutrient intakes of the subjects measured by the convenient method were generally lower than the level of RDA. The result of nutrient intake assessed has shown that the average energy intake was 1701${\pm}$316kca1 which is 85.1% of the RDA and the average calcium intake was 485.4${\pm}$172.3mg which is 69.3% of the RDA. The intakes of protein, vitamin A, vitamin B$_1$, niacin were greater than the RDA, whereas the remaining nutrient intakes were lower than the RDA. The average BMD of the subjects was shown to be 1.06${\pm}$1.09g/$\textrm{cm}^2$. The highest BMD of 1.24${\pm}$0.14g/$\textrm{cm}^2$ was noticed in the subjects of 30s compared to 20s, 40s, 50s, 60s. The BMD values were compared by the relative body weight(R3W) of the menopause subjects, and it was found that the underweight group had significant lower BMB while the rest of the groups did not have any differences in BMD. The most strongly correlated nutrient with BMD among the menopause subjects appeared to be calcium. The women whose Ca intakes were higher than 500mg showed the significantly higher BMD than those with Ca intakes lower than 500mg. This study suggests that the most effective way to prevent osteoporosis and to reduce the incidences of fractures seems to be minimizing bone loss through the adequate intake of calcium as well as avoiding underweight, especially in menopausal women. (Korean J Nutrition 31(9) . 1446-1456, 1998)

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.853-859
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• 2006

This study was carried out to investigate the effect of egg shell calcium salt types and egg shell membrane on calcium metabolism in rats. Sprague-Dawley male rats, 4 weeks of age, were fed on free-calcium diets for 2 weeks after adjustment period. Rats weighing approximately $247{\pm}2.3g$ were divided into 6 groups and were fed on the experimental diets containing 0.2% calcium for 4 weeks. Experimental groups were as follows; {ES(M+)} (egg shell powder diet with egg shell membrane), {ES(M-)} (egg shell powder diet without egg shell membrane), {AC(M+)} (egg shell calcium acetate diet with egg shell membrance), {AC(M-)} (egg shell calcium acetate diet without eg shell membrane), {GC(M+)} (egg shell calcium glucuronate diet with egg shell membrane) and {GC(M-)} (egg shell calcium glucuronate diet without egg shell membrane). Bone length of femur was significantly different by the types (p<0.05) of egg shell calcium salts. Bone mineral density of femur showed the highest level in AC(M-) group. Calcium content of femur and calcium absorption rate were higher in egg shell calcium salt groups than in eg shell powder groups. Calcium absorption rate and retention were significantly different (p<0.05) among the types of eg shell calcium salts and were higher in the AC(M-) group than in the other groups. Alkaline phosphatase activity, parathyroid hormone and osteocalcin levels of serum showed no significant difference among the experimental groups. From the above results, it is concluded that bioavailability of calcium is higher in groups of egg shell calcium salts compared to those in egg shell powder, even though egg shell membrane has no effect on calcium metabolism. Thus, these findings suggest the possibility of using egg shell calcium salts as a functional food material related to calcium metabolism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.255-261
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• 2006

This study was Conducted to investigate the effect of ${\gamma}-PGA\;({\gamma}-poly\;glutamic\;acid)$ on Ca absorption and bone metabolism in rats. Weaned 4-week old male rats were fed Ca-deficient diets for 3 weeks after the adjustment period. Rats were divided into 6 groups and were fed experimental diets for four weeks. Experimental groups were basal (Ca deficient), control (Ca diet: Ca 0.45%), CP1(Ca 0.45%+casein phosphopeptide 1%), PG1(Ca 0.45%+gamma poly glutamic acid 1%), CPG (Ca 0.45%+casein phosphopeptide 1%+gamma poly glutamic acid 1%) and PG3(Ca 0.45%+gamma poly glutamic acid 3%). Though daily Ca intake and food intake of experimental groups showed no significant difference that of control group. The values of fecal Ca excretion and urinary Ca excretion in groups fed ${\gamma}-PGA$ were significantly lower than that in tile control group. The values of Ca absorption in groups fed ${\gamma}-PGA$ were significantly higher than that in the control group. The levels of femur Ca in ${\gamma}-PGA$ supplemented group were significantly increased compared to the control group. Also, breaking force of femur in ${\gamma}-PGA$ supplemented group showed about 40% increase compared to the control group. These results show that ${\gamma}-PGA$ supplement could be helpful to increase Ca absorption as well as to intensify the femur strength and to increase the Ca content of femur in rats.

• Korean Journal of Community Nutrition
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• v.11 no.6
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• pp.793-807
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• 2006

This study was performed to estimate the effect of alphacalcidol supplementation or nutrition education on the nutrient intakes, bone mineral density and bone markers in continuous ambulatory peritoneal dialysis (CAPD) patients. The 90 CAPD subjects were randomly assigned to 3 groups (alphacalcidol group: AG, nutrition education group: NG, and control group: CG). Alphacalcidol supplementation($0.5{\mu}g/day$) was carried out for 8 months. Nutrition counseling was performed according to the patient s individual question for the first 6 months and scheduled nutrition education with individual counseling was carried out for the last 2 months. In baseline data. there were no significant differences in age, sex, family number, education years and monthly income except the NG showed significantly less duration of CAPD (p< 0.05) compared to other two groups. After intervention all three groups showed tendency of lower intakes. NG revealed less decrease in protein, especially in animal protein calcium from Ca-P binder, dietary calcium, dietary iron and niacin. NG showed significantly more increase in dry weight (p<0.05) and AG in waist circumference (p<0.001) after intervention. The groups did not show significant differences in the changes of biochemical indices related to bone metabolism. NG revealed more increase in trochanter BMD(p < 0.05) compared to other two groups. It seems that nutrition education is more effective in preventing deterioration or improving the bone and general nutrition status.