• 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 Food And Nutrition
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• v.21 no.1
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• pp.71-78
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• 2008

This study examined the effects of mulberry-leaf powder Tofu(MPT) on the anthropometric measurements, bone mineral density(BMD), biochemical markers of bone turnover, serum lipid levels of and macrominerals status in 30 female university students living in Choongnam with low dietary Ca intake was low(mean daily $intake=524.66{\pm}21.47$ mg/day). The subjects received the MPT supplemented(100 g/day) for 4 weeks. The nutrient content per 100 g MPT was 84.10 kcal(energy), 8.98 g(protein), 0.53 mg(fiber), 211.33 mg(Ca) and 1.59 g(fat). Anthropometric measurements, 24-hour dietary recall, carpus BMD using DEXA, select BMD biomarckers(serum alkaline phophatase activity, osteocalcin, urinary deoxypyridinoline), serum protein levels, albumin, and glucose levels, lipid profiles(cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol) and serum macrominerals(Ca, Ca/P ratio, Mg) were analyzed before and after MPT supplementation. Following MPT supplementation, there was no significant differences in anthropometric measurements, nutrient intakes, carpus BMD, serum alkaline phosphatase activity, osteocalcin, and urinary deoxypyridinoline, serum levels of protein, albumin, and glucose or lipid profiles with AI, HTR, LHR and CRF. However, there were significant increases in dietary calcium as well as decreases in serum triglycerides with MPT supplementation. Although further research is needed, these results that regular intake MPT could prevent bone and cardiovascular diseases.

• Animal Bioscience
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• v.35 no.12
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• pp.1940-1947
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• 2022

Objective: This study examined the effects of dietary calcium (Ca) and non-phytate phosphorus (NPP) on performance, tibial characteristics, meat quality and plasma biochemical variables in yellow-feathered broilers during 85 to 105 d of age. Methods: A total of 720 heads of 85-d broilers were allocated into 9 groups and provided with three levels of Ca (0.65%, 0.75%, 0.85%), and NPP (0.25%, 0.30%, 0.35%) in diets for 21 d. Results: The final body weight (FW), average daily gain (ADG), average daily feed intake (ADFI), and feed to gain ratio (F:G) were affected (p<0.05) by dietary Ca. From the quadratic regressions, the optimal level of Ca in diet were 0.71% for FW and ADG, and 0.67% for ADFI. Dietary Ca and NPP both significantly affected tibial breaking strength and density. From the quadratic regressions, the optimal level of Ca and NPP in diet were 0.81% and 0.37% for tibial density. The shear force of breast muscle of broilers given 0.75% or 0.85% Ca were lower than that in birds with 0.65% Ca and drip loss of birds given 0.65% or 0.75% Ca was lower than that in birds with 0.85% Ca (p<0.05). The drip loss of birds given 0.25% NPP was lowest among all NPP treatments (p<0.05). Calcium affected (p<0.05) the plasmal contents of phosphorus, osteocalcin (OC), parathyroid hormone (PTH) and calcitonin and the contents of OC and PTH were also influenced by dietary NPP. Conclusion: Dietary Ca and NPP level affected tibial characteristics, meat quality and biochemical variables in plasma of finisher-phase yellow-feathered broilers (85 to 105 d) and Ca also affected growth performance. Dietary 0.71% Ca and 0.30% NPP were enough for growth performance, while considering the growth performance, tibial characteristics, meat quality and biochemical variables together, 0.75% Ca and 0.37% NPP were recommended.

• Journal of Nutrition and Health
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• v.29 no.1
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• pp.59-69
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• 1996

Effects of dietary calcium(Ca), protein, and phosphorus(P) intake on bone mineral density (BMD) were investigated in 129 Korean premenopausal women(age 31-54 years) without diagnosed disease. BMD was measured at the spine(vertebrae L2-4) and femur(neck, Ward's triangle and trochanter). By stepwise multiple regression analysis it was shown that protein, Ca, and P intakes affected most significantly on BMD at the vertebrae L2-4, protein and P intakes affected most significantly on BMD at the femoral neck and Ward's triangle, and body mass index(BMI) affected most significantly on BMD at the trochanteric region. When ate-matched BMD % at the vertebrae L2-4 and all femoral sites was grouped by three levels(<90%, 90-99%, >=100%), only at the vertebrae L2-4>=100% and 90-99% groups had higher Ca intakes than <90% groups. When Ca, protein and P intakes of the recommended level for Korean(RDA) were grouped by three levels (Ca or P ; <=650mg/d, 650-750mg/d, >=750mg/d, Protein ; <=55g/d, 55-60g/d, >=65g/d), only at the vertebrae L2-4>55g/d of protein intake had higher age-matched BMD % than <=55g/d intake, >=750mg/d of Ca and P intakes, age-matched BMD % than <=650mg/d. In RDA range of Ca, protein, and P intakes, age-matched BMD % of the vertebrae L2-4 and all femoral sites was greater than 90%. Correlation between Ca intake and vertebral BMD was examined closer. There was more significant linear correlation between vertebral BMD and Ca intake below 800mg/d(r=0.346, p<0.0001)than above(r=0.376, p<0.019), implying a threshold effect and vertebral BMD was better expressed as a function of the logarithm of calcium intake(r=0.3881, p<0.0001). These results suggest that Ca, protein, and P intakes greater than RDA help to maintain proper BMD in middle-aged prementopausal women. Especially dietary Ca have important role in increasing the vertebral BMD and 800mg/d of Ca intake is optimum amount.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.80-86
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• 1996

Parathyroid hormone(PTH) is known to stimulate bone resorption and to inhibit bone collagen synthesis. In contrast, as the evidence of stimulation of bone formation by PTH has recently been observed, the study on the role of PTH involved in osteoporosis draws remarkable attention. This study has dealt with the role of alkaline phoshatase(AP), a marker enzyme for bone formation and osteoblast action, Animals(BALS/cmice) were divided into three dietary groups(high and medium Ca and Ca-free) and hormones including PTH, calcitonin(CT), cholecalciferol(citamin D) were i.p. injected. AP in the serum and liver was measured using Sigma 221 alkaline buffer solutions containing 9mM of p-nitrophenyl phoshate. Enzume was reacted at 37$^{\circ}C$ for 10 minutes and the reaction was stopped by 1.8ml of 0.1N NaOH and measured at 410nm. We found that serum and liver AP activity was increased by low dietary Ac. Compared to the control, and serum Ap activity was enhanced by PTH and vitamin D regardless of the dietary Ca. On the other hand, liver AP activity was inhibited by OTH and vitamin D at all levels of dietary Ca. CT inhibited the action of PTH and vitamin D in the serum. But, the inhibition of PTH and vitamin D action by CT was not observed in the liver, unlike in the case of serum.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.13-22
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• 1994

This study was designed to investigate the effects of dietary protein and caffeine consumption levels on Ca, P, Na and K metabolism. One hundred twenty rats were divided into twelve groups according to age, protein level and caffeine consumption such as group(120-130g young rat, 250-300g adult rat) , dietary protein group (20% normal protein , 85 low protein) , caffeine consumption group(0, 3.5mg, 7.0mg). Low protein diet containing high caffeine levels caffeine levels increased calcium, phosphorus, sodium and potassium contents of urine and fecal in rats. Young rat has higher level of calcium, phosphorus , sodium and potassium than adult rat. In the serum, calcium contents were not affected by age, dietary protein levels and caffeine consumption . However, phosphorus, sodium and potassium contents of serum in adult rat were higher than young rat. In the liver, potassium decreased with decreasing dietary protein levels. In the kidney, calcium , phosphorus and potassium contents were not different by age group, dietary protein levels and caffeine consumption , but sodium content was significantly reduced in the adult rat.

• Preventive Nutrition and Food Science
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• v.7 no.4
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• pp.367-372
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• 2002

This study investigated the effects of dietary soy protein and Ca on the lipid profiles of rats fed fat-enriched diets. Rats were divided into two groups and fed either a casein-low Ca (Exp I) or ISP-high Ca diet (Exp II) for a control period of 4 weeks. The two groups of rats were again subdivided into 4 groups and fed one of 4 experimental diets for another 4 weeks. The experimental diets consisted of 18% beef tallow and 1 % cholesterol, in which either 20 % casein or ISP with one of two levels of Ca, high (1 %) or low (0.1 %). The concentrations of total lipid, cholesterol and triglyceride in serum, liver and feces were determined. At the end of the control period, the serum total lipid and cholesterol concentrations were low in the rats fed ISP-high Ca diet (67~76% and 83~86%). During the next 4 week period, these concentrations remained significantly lower in rats fed the diets containing ISP and high Ca compared with those on casein and low Ca diets (p ＜ 0.05). Total lipid and cholesterol concentrations in feces were significantly higher in the ISP-high Ca dietary group at 4 weeks, and high in both high Ca groups at 8 weeks. This study demonstrates that both soy protein and Ca reduce serum and liver cholesterol, triglyceride, and total lipid in rats fed fat-enriched diet, and that they have an additive effect when combined.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1236-1242
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• 2007

Sixty healthy growing pigs ($Duroc{\times}Landrace{\times}Yorkshire$ with an average BW of 21.4 kg) were used to determine the true digestible phosphorus (TDP) requirement of growing pigs on the basis of growth performance and serum biochemical indices. Pigs were assigned randomly to one of five dietary treatments (12 pigs/diet), representing five levels of TDP (0.16%, 0.20%, 0.23%, 0.26% and 0.39%). There were three replications per treatment, with four pigs (2 barrows and 2 gilts) in each replication (2 pigs/pen) A randomized-block design was used, with pen as the experimental unit. Experimental diets were formulated to provide the 5 TDP levels with a total calcium (Ca) to TDP ratio of 2:1, and offered to pigs at 5% BW for 28 d. The total Ca contents of the five diets were 0.33, 0.38, 0.45, 0.51 and 0.79%, respectively. During the 28-d experimental period, the ADG of pigs was affected by dietary TDP levels as described by Equation 1: y = $-809,532x^4+788,079x^3-276,250x^2+42,114x-1$,759; ($R^2$ = 0.99; p<0.01; y = ADG, g/d; x = dietary TDP, %). The feed:gain ratio for pigs was affected by dietary TDP levels as described by Equation 2: y = $3,651.1x^4-3,480.4x^3+1,183.8x^2-172.5x+10.9$ ($R^2$ = 0.99; p<0.01; y = feed:gain ratio; x = dietary TDP, %). Total P concentrations in serum were affected by dietary TDP levels as described by Equation 3: y = $-3,311.7x^4+3,342.7x^3-1,224.6x^2+195.6x-8.7$ ($R^2$ = 0.99; p<0.01; y = total serum P concentration and x = dietary TDP, %). The highest ADG (782 g/d), the lowest feed:gain ratio (1.07), and the highest total serum P concentration (3.1 mmol/L) were obtained when dietary TDP level was 0.34%. Collectively, these results indicate that the optimal TDP requirement of growing pigs is 0.34% of the diet (e.g., 5.1 g/day for a 30-kg pig that consumed 1.5 kg feed daily) at a total Ca to TDP ratio of 2:1.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.248-255
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• 2012

Three levels of boron (0, 30, 60 ppm) were supplemented in practical corn-soybean based starter and grower diets, containing either adequate or inadequate Ca or P. A total of 1,800, 1-day-old sexed broiler chicks were assigned to six dietary treatments and fed with the experimental diets for 42 days. Boron improved the overall feed conversion ratio, but increased body weight only at 21 days of age (p<0.01). Boron decreased feed intake in the case of feeding on a diet deficient in Ca and P, and tended to increase feed intake when birds received a diet adequate in Ca and P, signifying significant boron by Ca-P interaction (p<0.01). Mortality was not influenced by boron (p>0.05). Dietary Ca and P deprivation reduced body weight and feed consumption significantly, but did not influence the feed conversion ratio and mortality (p>0.05). Serum Ca level, ALP and ALT activities were not influenced either by dietary Ca and P deficiency or boron supplementation. Serum P content increased with respect to boron at 30 ppm. Bone breakage strength was not affected by dietary variables. Tibia ash, Ca and P were increased in response to the supplementation diet with 30 ppm boron, whereas 60 ppm showed no effect in most cases. Accordingly, the dietary boron supplementation of 30 ppm significantly decreased fecal Ca and P excretion, while there was a numerical decline in the 60 ppm boron as compared to the 0 ppm boron group. Data presented herein indicated that boron, either at the 30 ppm or 60 ppm supplementation level, was effective in conversion of feed to body weight, whereas only boron at 30 ppm contributed to the mineralization of bone thereby augmenting more Ca and P while excreting less through faeces.

• Journal of Nutrition and Health
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• v.22 no.6
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• pp.497-506
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• 1989

To investigate the effect of levels of dietary protein and age on bone metabolism 40% and 5% casein were fed to the rats of 2 & 13 months of age for 12 weeks. High protein groups showed higher bone weight and Ca content than low protein groups and urinary Ca loss was increased in high protein groups but the difference disappeared gradually. A significant increase in urinary hydroxyproline excretion was noted in high protein groups of both age. Another short term study was undertaken to study if the above effect was related with renal function or PTH. Extremely high and low protein diets(60%, 6%) were fed to the rats of different ages(6wks, 6mos.) for 2 weeks, Urinary Ca excretion was significantly increased in high protein groups of young and aged rats and GFR was increased as well. There was no difference in serum iPTH levels between low and high protein groups, but it was elevated in aged rats. Alkaline phosphatase activity was higher in young rats, reflecting faster bone formation. The observed hypercalciuria in high protein groups, especially in aged rats, seems to be related to higher GFR, and PTH dose not appear to be a major mediator.