STUDIES OF RICE-BRAN THERAPY FOR CALCIUM UROLITHIASIS WITH IDIOPATHIC HYPERCALCIURIA

III. Effects of Rice-bran on Calcium Balance in Rats

Abstract

The purpose of this study is to assess the biological effects of rice-bran or phytin. Metabolic balance studies of calcium were carried out in male rats during treatment with rice-bran, phytin and Na-phytate, and evaluated the influence of high and low dietary calcium intakes on their effects.
The following results were obtained:
1) When rats were fed with the high calcium diet, urinary calcium excretion was significantly reduced by treatment with rice-bran and phytin. There was no significant difference in the effect between rice-bran and phytin.
2) In the low calcium diet, rice-bran and phytin had no significant effect on urinary calcium excretion. A marked difference in the reduction of urinary calcium was observed between the high calcium diet and the low calcium diet.
3) Similar effects on urinary calcium excretion were obtained on administration of Na-phytate (200mg/day).
4) On the high calcium diet, rice-bran and phytin significantly reduced the absorption of calcium in the intestines. In contrast, its reduction was slight on the low calcium diet. These findings suggest that utilization of phytate phosphorus probably enhances on the low calcium diet, and diminishes on the high calcium diet.
5) The whole group of this study had no significant effects on serum calcium and parathyroid hormone. Growth rate and calcium contents in the femur were affected by rice-bran and phytin administration.
6) Rice-bran treatment was suggested to be more effective with high dietary calcium intake. This result should be taken into consideration in its clinical use.