• Journal of Nutrition and Health
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• v.13 no.3
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• pp.134-138
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• 1980

The present study was designed to investigate the effects of the level of calcium intake on it's apparent absorption rate in college women. Six college girls aged 19 to 20 were fed general dormitary meals containing approximately500mg of calcium for one week and thereafter, the experimental diets containing about 800mg of calcium were given for one week. Average values for calcium intake, fecal excretion of calcium, and apparent absorption rateof calcium in both periods were determined and these values for two periods were compared by using t-test. 1) Average intakes of calcium, protein, and fat of the subjects during the period of experimental diet were significantly higher than those of general diet period. 2) Higher consumption of three food groups; meat, poultry, and fishes, fruits and vegetables, and fats and oils were noted during experimental period. However, there was no significant difference in the consumption of cereals and milk groups during these two periods. 3) The apparent absorption rate of calcium during the experimental period was higher (64%) than the one for general diet period (56%). It was noteworthy that average calcium intakes was higher during the experimental diet period (785mg) than 536mg for general diet period while the fecal excretions of calcium in both periods were not significantly different.

• Journal of Nutrition and Health
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• v.13 no.1
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• pp.37-41
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• 1980

This study was designed to investigate calcium intake, calcium excretion, and calcium absorption rate of the college women in Korea. The subjects of this experiment were five healthy college women aged from 18 to 23 years who lived in Seoul. The period of this experiment was two weeks, the first week was spent in having an ordinary diet and the next week for the experimental diet. Two weeks later, the feces of subjects were collected. Results obtained by the present experiment were as follows: 1) The total food intake from the experimental diet daily was about $1600{\sim}2000g$. 2) The total calcium intake was about $270{\sim}585mg$ and $710{\sim}880mg$ for the ordinary diet and the experimental diet respectively. 3) The daily calcium excretion of feces was about $219{\sim}295mg$. 4) The calcium absorption rate of subjects was about $60{\sim}70%$.

• 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.

• Journal of Nutrition and Health
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• v.36 no.7
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• pp.684-690
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• 2003

This study has investigated the bioavailability of calcium in eggshell powder (ESP) for the purpose of reutilizing eggshells as the calcium source. The experiment was designed 2 ${\times}$ 2 factorial method with two sources, CaCO$_3$ and ESP, and two levels, 0.2% and 0.4% calcium. Weanling SD rats were assigned randomly to one of 4 groups and provided by one of the isocaloric, 20% casein based 4 different experimental diets for 4weeks. Deionized water was given and environment was kept from any contamination of minerals. The body weight, diet intake, feed efficiency ratio (FER), bone growth, Ca contents of bones, and apparent absorption were measured. FER (0.38 - 0.40) and kidney weight were not different among groups and the weight and length, Ca content, strength of two bones Tibia and Femur were not affected by Ca sources except Femur Ca content. Ca content of Femur was greater in ESP groups than that of CaCO$_3$ groups. The body weight gain, bone growth, the Ca contents and strength of bones were significantly greater in 0.4% calcium groups suggesting 0.2% calcium is not sufficient for the optimum growth in the growing rats. These results indicate that ESP be a proper Ca source comparable or superior to CaCO$_3$. However the apparent absorption rate of final 3 days of feeding did not support the observed results showing lower rate in ESP than CaCO$_3$ groups. Further study be needed in the absorption aspect.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.1
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• pp.42-47
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• 1987

The present studies were undertaken to prepare calcium acetate from sea-mussel shell and then, to investigate the calcium absorption ratio for calcium acetate by using young albino rate male. Purities such as chloride, nitrate, nitrate, sulfate, phosphate and heavy metal passed to test as reagent grade and calcium acetate assay was 99.0%. No significant differences in the body weight gain between calcium acetate group, calcium gluconate group and calcium carbonate group were not recognized. Diet consumptions of calcium acetate group was almost similar with calcium gluconate group and calcium carbonate group. It was found that absorption rate of calcium acetate was $57.68{\pm}0.83%,\;58.08{\pm}0.94%$ and was $2.0{\sim}3.0%$ high than calcium gluconate and calcium carbonate group.

• Journal of Nutrition and Health
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• v.21 no.2
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• pp.99-112
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• 1988

This study was performed to investigate the effects of dietary protein and calcium levels on calcium metabolism in eight healthy Korean adult females. The 2-day metabolic study consisted of a 2 day adaptation period and three 6-day experimental periods. Three experimental diets were low protein low calcium(LPLCa : protein 44g, Ca 422mg), higher protein low calcium(HPLCa : protein 85g, Ca 365mg), and high protein high calcium (HPHCa : protein 84g, Ca 727mg). The apparent calcium absorption was likely to be affected by the calcium intake rather than by the protein intake. Average calcium absorption rate was about 23-29% of calcium intake. The calcium balance was -21.44mg for LPCa, -25.02mg for HPLCa, and -3.22mg for HPHCa. Avergae urinary calcium excretion was 127.7mg for LPLCa, 108.6mg for HPLCa, and 215.4mg for HPHCa. Urinary calcium excretion was more closely related to the changes of calcium intake rather than of protein intake. These results seemed to be due to the interactions between the high phosphours contained in the high protein diet and the little discrepancy of protein intake levels.

• The Korean Journal of Community Living Science
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• v.19 no.1
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• pp.75-85
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• 2008

This study investigated the effects of chitosan on mineral metabolism in rats exposed to cadmium by oral administration. Six week-old Sprague-Dawley rats were divided into eight groups. Four groups were fed AIN-93G based 3% ${\alpha}$-cellulose diets and the other four groups were fed 3% chitosan diets for four weeks with the oral administration of 0, 0.5, 1.0, 2.0 mg Cd/2ml distilled water three times per week, respectively. The essential mineral contents of serum, liver, kidney and bone (femur and lumbar), and the excretion of calcium in feces and urine were determined. There was no significant difference in weight gain and food intake among groups. The cadmium administration significantly decreased calcium in serum, iron in blood, calcium and iron in liver and iron contents in kidney. In contrast, calcium and zinc contents in kidney increased by the administration of cadmium. The weight, length and breaking forces of the femur and lumbar were not significantly different due to cadmium administration and chitosan among the groups. The fecal excretion of calcium was increased by the administration of cadmium. On the other hand, calcium absorption and the absorption rate were decreased by Cd administration. In the groups without Cd administered (N, N-Chi groups), chitosan significantly decreased the absorption rate of calcium by increasing the excretion in feces (p<0.05). These results suggest that cadmium administration may facilitate the decline of essential minerals in rats and also, chitosan may have a conflicting effect between cadmium and the essential minerals of tissues.

• Journal of Nutrition and Health
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• v.30 no.3
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• pp.266-276
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• 1997

To investigate the effects of dietary protein and calcium levels on calcium and bone metabolism Sprague-Dawley male growing rats weighting approximately 91.4g were divided into four groups and fed one of the following four experimental diets-15% protein 0.2% calcium ; 15% protein 0.5% calcium ; 30% protein 0.2% calcium ; 30% protein 0.5% calcium-for five weeks. Calcium intake and excretion, apparent calcium absorption were measured and bone densities and mineral contents of femur and scapula were analyzed. Calcium excretion through feces and urine was significantly greater in animals receiving diets of higher calcium. Fecal calcium but not urinary calcium excretion was greater when the protein level was increased from 15% to 30%. Apparent calcium absorption rate was significantly higher with lower calcium intakes. Serum alkaline phosphatase activity was significantly higher in 0.2% calcium group than in 0.5% calcium group, while urinary hydroxyproline excretion was essentially same among all experimental groups. Weights and mineral contents or protein. Bone weights were greater, but calcium and ash contents of femur and scapula were lower in animals on the diet containing low calcium and high protein, which suggests that bone metabolism may be affected by the interaction between calcium and protein intake. These results indicate that during growth high protein intake might be beneficial to bone health if the diet is sufficient in calcium, however, if the diet fails to provide an optimum amount of calcium, such practice might be detrimental.

• Journal of Nutrition and Health
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• v.34 no.4
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• pp.433-439
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• 2001

Intakes and excretions of calcium and phosphorus were determined for 8 female adolescents(aged 16.3$\pm$0.5y; body mass index 20.4$\pm$1.3kg/$m^2$; body fat 33.3$\pm$2.5%; bone mineral density of lumbar spine in L2-L4; 0.96$\pm$0.08g/$\textrm{cm}^2$) when they consumed diets basal and high in calcium for 6 days each. All subjects consumed a basal Ca diet containing 800mg, Korean RDA level of the subjects, and a high Ca diet containing 1200mg, RDA plus 2 SDs of calcium intake. The diets provided 58% of energy intake as carbohydrate, 25% as fat, and 17% as protein. Food, urine, and fecal composites were collected during the last 3 days of each feeding period. Fecal excretion of calcium was significantly greater on the high Ca than on the basal Ca diet. Hence, apparent absorption rate was significantly lowered from 40.9% on the basal Ca diet to 33.1% on the high Ca diet. There was no significant difference in calcium retention between the two diet periods but it tended to be greater on the high Ca diet. However, excretions and retention of phosphorus did not show any significant difference even though intake was significantly increased from 1,253mg on the basal Ca diet to 1,583mg on the high Ca diet. The results indicate that higher calcium intake than the Korean RDA level is recommended for adolescents to meet peak bone mineral accretion and attain a desirable level of calcium retention. (Korean J Nutrition 34(4) : 433~439, 2001)

• 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.