• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.833-839
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• 2005

This study was conducted to demonstrate whether dietary Ca and the soy isoflavones supplementation could reduce the bone loss associated with estrogen deficiency. Nine week-old female rats (SD) were ovariectomized and then fed on diet of low $(0.1\%)$ or normal $(0.5\%)$ Ca supplemented with soy isoflavones (80 and 160 ppm) for 6 weeks. The ovariectomized and sham-operated rats showed normal serum Ca and P levels, and dietary Ca and soy isoflavones did not changed them. The serum alkaline phosphatase activity was increased in all ovariectomized rats, especially in the rats fed low Ca diet regardless of isoflavone supplementation. The serum tartrate-resistance acid phosphatase was not significantly different among the ovariectomized rats and were not changed by dietary Ca and isoflavones. Breaking force of femur was higher in the rats fed the nomral Ca diets and not statistically changed by soy isoflavone supplementation. Femoral and lumbar Ca and P contents decreased in the ovariectomized rats and the soy isoflavones-80 ppm supplementation significantly enhanced bone minerals, but the soy isoflavones-160 ppm supplementation did not. Dietary Ca increased lumbar Ca and P contents. The results of this study have suggested that the soy isoflavones 80 ppm supplementation could be sufficient to prevent bone loss in ovariectomized rats and normal Ca supplementation could enhance the effect of soy isoflavones on bone protection.