Abstract
This study was designed to investigate the effect of dietary boron supplementation and calcium levels on calcium and bone metabolism in ovariectomized female rats. The experimental group classified ovariectomized group(O) and sham operation group (S). The two groups were then each randomly divided into flour sub-groups and fed experimental diets consisting in two levels of calcium and at each level of calcium, there were boron supplemented group and non-supplemented group. Calcium levels were either 0.2%(low calcium group: L) or 1.2%(high calcium group: H). The level of boron in the diet for the boron supplemented groups(B) was 100$\mu\textrm{g}$/g diet. The experimental period was six weeks. The average food intake were not statistically significantly different in all of eight groups. The increase in weights of rats was observed only in ovariectonized and sham control rats(low ca without boron supplemented). The rest of the groups lost weight significantly during the experimental period ranging from 26.94g to 44.34g. Significant higher calcium intakes were observed in high calcium groups, regardless of boron supplementation during experimental period. Urinary calcium excretion was not affected either by ovariectomy or diets on the first, third and sixth week of feeding. Apparent calcium absorption rates were not different among the groups on first week, whereas noticeable increase was observed in low calcium groups at third and sixth weeks. Femur wet and dry weight, and calcium contents of femur were higher in low calcium groups. whereas femur bone density was higher low calcium with boron supplementation groups than low calcium groups. Scapular density did not show any significant differences among all groups. Despite there were no differences in the activities of alkaline phosphatase by boron supplementation, boron supplemetation appeared to cause higher femur density. There results suggest that in both of sham-operated and ovariectomized rats low calcium did not influence greatly bone status of rats and boron increased bone density.
