• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.176-180
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• 2005

This study was conducted to examine effect dietary protein and calcium levels on calcium metabolism of the rat. Weaned 6-week old male rats were divided into 4 groups and were fed experimental diets for six weeks. Experimental groups were HPNC group-high protein normal calcium (protein: 400 g/kg diet, calcium: 0.5%), HPLC group-high protein low calcium (protein: 400 g/kg diet, calcium: 0.1%), NPNC group-normal protein normal calcium (protein: 200 g/diet, calcium: 0.5%), NPLC group-normal protein low calcium (protein: 200 g/diet, calcium: 0.1%). The calcium excretion in urine was higher in high protein group than in normal protein group, and it was highest in HPLC group. The activation of alkaline phophatase had a tendency to low in normal calcium group, and the concentration of parathyroid hormone (PTH) was the lowest in HPLC group. The deoxypyridinoline (DPD) concentration of urine was investigated as the highest in HPLC group and it was significantly lower in HPNC group that consumed normal calcium. The bone density of the femur was the highest in NPNC group and the lowest in NPLC group. As the results of this study, calcium excretion in urine and DPD density were the highest and the bone density was the lowest in HPLC group. It may suggest that the deficiency of calcium causes adversely effect in calcium metabolism upon consuming high protein diet. Therefore, it should be emphasized to consume enough calcium to prevent the hindrance of skeletal metabolism caused by deficiency of calcium upon consuming high protein diet.

• Journal of Nutrition and Health
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• v.47 no.2
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• pp.89-98
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• 2014

Purpose: Association of low intake of calcium (Ca) and inadequate vitamin D (VD) status with higher prevalence rates of obesity has been reported. This study was conducted in order to investigate the effects of different levels of whey Ca and VD intake on lipid metabolism in growing rats. Methods: A total of 56 five-week-old male Sprague-Dawley rats were divided into seven groups and fed for five weeks. Ca groups were divided into three levels, low, normal, and high (0.25%, 0.5%, 1%). VD subgroups in the low and high Ca groups were divided into three levels, low, normal, and high (10 IU, 1,000 IU, and 5,000 IU). The effects of Ca and VD on each group were evaluated by two way ANOVA. Results: Significantly higher amounts of abdominal fat, visceral fat, and epididymal fat were observed in the Low-Ca groups than in the Normal-Ca and High-Ca groups. Serum leptin levels of Low-Ca groups were higher than those of Normal-Ca and High-Ca groups. The highest serum parathyroid hormone concentration was observed in the low Ca low VD group. The levels of serum 25(OH)D were significantly increased with increasing dietary VD levels. Significantly higher serum levels of triglycerides, total cholesterol, and HDL-cholesterol were observed in the low Ca groups than in the normal Ca and high Ca groups. Conclusion: These results indicate that low calcium intake increased serum lipid level and body fat amount.

• 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.