• Nutritional Sciences
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• v.1 no.1
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• pp.16-21
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• 1998

This study was conducted to determine the interaction of dietary wheat bran and dietary calcium levels n)n calcium utilization in post-breeding female rats. It was designed to compare the effects of four different levels (2.5, 5, 10 and 20%) of wheat bran and two different levels (0.5 and 1%) of calcium on bone and calcium balance in post-breeding female rats over a ten-week period. The effects of diet on animal weight gain, serum calcium, femur weight, femur calcium concentration, bone mass and calcium balance were determined and statistically analyzed. The addition of 20% wheat bran significantly (p$\leq$0.05) decreased the weight gain of rats. Serum calcium and bone calcium contents were more affected by dietary calcium level than by dietary wheat bran level. There was no significant difference in fat-free solid, ash, percentage of ash to fat-free solid and percentage of calcium to ash among groups. Groups fed the 1% calcium diet had a higher percentage of calcium to fat-free solid. All rats were in positive calcium balance during the three-4ay experimental period. The average calcium balance of the rats fed 1% calcium diet ranged from 25.34 to 53.90mg and the average calcium balance of the rats fed the 0.5% calcium diet ranged from 26.71 to 32.90mg. In rats receiving 2.5% wheat bran, the difference in calcium balance between the group fed the 1% calcium diet and the group fed the 0.5% calcium diet was only 1.37mg, which was not significantly (p$\leq$0.05) different. In rats receiving 20% wheat bran, the difference in calcium balance between the group fed the 1% calcium diet and the group fed the 0.5% calcium diet was 19.S7mg, which was significantly (p$\leq$0.05) different. The addition of wheat bran caused an increase in the calcium balance of the rats adminslesed the 1% calcium diet. On the other hand, the addition of wheat bran had no effect on the calcium balance of the rats adminislesed the 0.5% calcium diet. In conclusion, calcium utilization of rats wire more positively affected by the interaction of both dietary wheat bran levels and dietary calcium levels than either dietary wheat bran levels or dietary calcium levels alone. Moderate wheat bran consumption did not interfere with the calcium metabolism of rats when calcium intake was high enough.

• Journal of Nutrition and Health
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• v.28 no.2
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• pp.144-151
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• 1995

This study investigates the supplementing effects of milks by various heat treatment on growth performance and protein and calcium metabolism of rats. For 4 weeks, raw, LTLT-HTST-and UHT-processed milks were given to rats which fed on a calcium free, semi-synthetic diet containing 5%casein. There were no significant differences among the experimental groups in weight gain, feed efficiency ratio and the serum level of total protein and calcium. Also, no significant differences were showed in protein efficiency, nitrogen balance, apparent protein digestibiltiy and the contents of weight and calcium of the left femur as well as 2 incisors. However, the biological value of protein in the UHT-milk group was significantly higher than that of the raw-milk group. The apparent calcium digestibility and calcium balance in the UHT-milk group were higher than those in the raw-, LTLT- and HTST-milk groups. The weight of left femur in all the groups supplemented with various heat-treated milks was significantly impair the nutritive value of protein and calcium in milk. Futhermore, UHT-processing may improve the bioavailability of protein and calcium in milk.

• Korean Journal of Community Nutrition
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• v.3 no.2
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• pp.218-227
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• 1998

This study was performed to investigate the effects of dietary protein and calcium levels on iron and zinc balance in eight healthy Korean young women. The 20-day metabolic study consisted of a 2-day adaptation period followed by three 6-day experimental periods. Three experimental diets were the low protein-low calcium(LProLCa ; protein 44g, Ca 422mg), the high protein-low calcium(HProLCa ; 'protein 85g, Ca 365mg) and the high protein-high calcium (HProHCa ; protein 84g, Ca 727mg). Apparent absorption and balance of iron and zinc were significantly higher when subjects were fed high protein-low calcium diet than low protein-low calcium diet. The elevation of dietary calcium significantly depressed the apparent absorption of iron and zinc. The levels of serum iron and zinc were likely to be increased with a high protein diet, but the differences were not significant. There was a strong correlation(r=O.99) between the iron intake and serum iron concentration. Serum zinc concentration was not correlated with hair zinc. Study results revealed that the levels of dietary protein and calcium influence iron and zinc balance in Koreans. This study suggests that dietary recommendations for trace minerals, such as iron and zinc, should be carefully examined. In addition, there is a need to evaluate the bioavailability of milk or beverage products enriched with calcium and iron.

• Journal of Nutrition and Health
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• v.38 no.1
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• pp.40-47
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• 2005

This study was performed to determine the effect of three different concentrations of soy-isoflavones on calcium and phosphorus balance in either sham-operated or ovariectomized female rats. Seventy-two 16-week old Sprague-Dawley rats underwent sham operation or bilateral ovariectomy. They were provided diets containing different levels of soy iso-flavones for 6 weeks: 50 ppm (Jow isoflavone intake; LI) , 250 ppm (medium isoflavone intake; MI) and 500 ppm (high isoflavone intake; HI). The subsequent fecal and urinary excretions of calcium and phosphorus were then measured. In the sham-operated rats, body weight gains and food efficiency ratio of the MI and HI groups were significantly lower than the control group while food intake was not different. However, there was no significant difference in the ovariectomized rats. The fecal excretion of calcium was significantly lower in the LI, MI and HI groups than the control group in sham operated rats, and significantly lower in the HI group than the control group in ovariectomized rats. Also, apparent ab-sorption rate of calcium and phosphorus did not show any significant difference among groups. Urinary excretion of calcium and phosphorus was significantly lower in the HI group than the LI group in the sham-operated rats. Urinary excretion of calcium was significantly higher in the control ovariectomized rats than in the control sham-operated rats. Retention of calcium and phosphorus did not show any significant difference in both groups. From the above result, we see that isoflavone intake increases calcium retention through an increase in calcium absorption and also suppresses the increase of calcium excretion in urine in ovariectomy. Therefore, it is suggested that isoflavone intake is recommended for menopausal women who experience sharp bone loss due to the decrease in estrogen honnone.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.1006-1015
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• 1996

This study was carried out to investigate the effects of dietary calcium-salt, estrogen-treatment, and estrogen/calcium treatment on calcium, phosphorus and nitrogen metabolism. Female Sprague-Dawley rats with a body weight of 250~280g were underwent ovariectomy or sham-operation. The ovariectomized rats were divided into 9 different experimental groups including the saline-treated group, the estrogen-treated group, the high calcium salt-treated group, and the estrogen/calcium treated groups and fed for 6 weeks. Each group daily intake and excretion of calcium, phosphorus and nitrogen were measured and apparent digestibility and balance were also studied. The results were as follows: The excretion level of winn calcium was significantly higher the ovariectomized rats than the sham-operation group(p<0.01) and reduced with estrogen treatment but this difference was not statistically significant. Fecal loss of calcium was higher the ovariectomized rats than the sham-operation group(p<0.001). When the estrogen was treated, fecal loss was decreased and then apparent digestibility of calcium was increased. Calcium balance was significantly higher the high calcium treated groups than the control diet groups. The excretion level of urinary Phosphorus was higher the ovariectomized rats than sham-operation group, while these showed to be decreased in the calcium salt, the estrogen and the estrogen/calcium treated groups(p<0.01). Fecal loss of phosphrous was higher in the ovariectomized rats. When the estrogen was treated, the fecal loss was decreased in the avariectomized rat than that of other groups. The excretion level of urinary nitrogen was higher the ovariectomized rats than the sham-operation, while these showed to be decreased in the estrogen, the estrogen/calcium, and the estrogen gradually reduction/calcium intensification. Fecal loss of nitrogen was decreased in tile estrogen treated group. The results in this study showed that high calcium, estrogen/calcium and estrogen gradually reduction/calcium intensification in the ovariectomized rats enhanced calcium balance compared to the ovariectomized rats without calcium treatment, but little effects on the phosphorus and nitrogen balance.

• Journal of Nutrition and Health
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• v.30 no.1
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• pp.32-39
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• 1997

This study was desiged to investigate the effects of calcium supplementation on the metabolism of sodium and potassium and blood pressure in seven healthy college women, aged from 19 to 21 years old. For this purpose, metabolic studies were conducted for two weeks. During the first week, the subjects ate experimental diet of which nutrients composition was similar to their usual intake. And during the consecutive second week, they ate the same experimental diet supplemented with 500mg or calcium daily. The results were summarized as follows : 1) Urinary excretion of sodium was significantly increased(p<0.05), but fecal excretion and retention of it was not affected by supplementary intake of calcium. 2) Potassium balance was not changed after additional intake of calcium. 3) Serum sodium and potassium level decreased significantly(p<0.05), but aldosterone and renin levels in serum were not changed by additional intake of calcium. 4) Systolic blood pressure(SBP) was not affected, but diastolic blood pressure (DBP) was significantly decreased (p<0.05) by supplementation of calcium. The above results showed that daily supplementary intake of calcium can be effective to decrease diastolic blood pressure through inducing the change of sodium metabolism in young women eating usual Korean diets.

• 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)

• 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.

• Journal of Nutrition and Health
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• v.41 no.3
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• pp.206-215
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• 2008

The purpose of this study was to investigate the effect of manganese (Mn) supplementation on bone status and calcium balance in ovariectomized rats according to the calcium intake levels. Total of 50 Sprague Dawley female rats (6 weeks) were divided into 5 groups and bred for 12 weeks: sham operated control group (SACa), OVX Ca deficiency group (OLCa) with Ca deficiency diet (0.1% Ca modified AIN-93N diet), OVX Ca deficiency & Mn supplement group (OLCaMn), OVX adequate Ca group (OACa; 0.5% Ca AIN-93N diet) and OVX adequate Ca & Mn supplement group (OACaMn). BMD (bone mineral density) of the femur was increased by Mn supplementation in OVX adequate Ca group. However, BMDs of spine, femur and tibia were lowered in OLCa compared to the OLCaMn group. Bone strength of tibia in OLCaMn group was significantly lower than OLCa group. Serum ALP (alkaline phosphatase) and CTx (C-telopeptide of collagen cross-links) levels were significantly higher in ovariectomized rats than those in the sham group, but they were not changed by Mn supplementation. Ca retention rate and Ca absorption rate did not differ among the experimental groups. Urinary Ca excretion was increased by Mn supplementation in Ca deficiency rats. In summary, Mn supplementation resulted in positive effects on bone mineral density ovariectomized rats with which intake adequate Ca. However, Mn supplementation on Ca deficiency ovariectomized rats resulted in decrement of BMO and bone strength by increasing Ca excretion. Therefore, it is encouraged to consider calcium intake levels in supplementation of manganese in order to prevent postmenopausal osteoporosis and to keep bone healthy. (KoreanJNutr2008; 41(3): 206~215)

• Journal of Nutrition and Health
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• v.28 no.8
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• pp.749-758
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• 1995

In this study, the food intake, feces and urine of 16 primary school age boys and girls were collected and intake and excretion of sodium and calcium were measured. The boys and girls were 8-12 years old and measurement continued for four weeks during which they maintained their normal living pattern and body weight. Each boy's and girl's daily intake and excretion of sodium and calcium were measured and apparent digestibility and balance were also studied. The results were as follows. 1) Mean daily intake of sodium was 8.52$\pm$0.38g for the boys and 7.31$\pm$0.44g for the girls. The mean value in males was significantly higher than that in females(p<0.05). Mean daily in take of calcium was 411.0$\pm$16.0mg for the boys and 356.5$\pm$15.4mg for the girls. The mean value in males was significantly higher than that in females(p<0.01). 2) Mean daily fecal loss and apparent digestibility of sodium was 0.32$\pm$0.04g and 96% for the boys and 0.52$\pm$0.07g and 93% for the girls. The fecal loss mean value in males was significantly lower than that in females(p<0.05). Mean daily fecal loss and apparent digestibility of calcium was 299.8$\pm$8.3mg and 29% for the boys and 194.1$\pm$14.3mg and 46% for the girls. The fecal loss mean value in males was significantly higer than that in females(p<0.01). 3) Mean daily urinary loss of sodium was 6.55$\pm$0.50g and showed the positive balance of 1.65g for the boys and 5.67$\pm$0.20g and showed the positive balance of 1.12g for the girls. The urinary loss mean values of the two groups were not significantly different. Mean daily urinary loss of calcium was 42.8$\pm$5.1mg and showed the positive balance of 79.4mg for the boys and 25.0$\pm$1.64mg and showed the positive balance of 137.4mg for the girls. The urinary loss mean value in males was significantly higer than that in females(p<0.01).