Abstract
In order to study and compare the effects of the different forms of commonly used vitamin D and phosphate-binders on the absorption and excretion of calcium and phosphate in the growing organism, 24 Sprague-Dawley weanling rats, weighing 44 to 62 grams, were randomly assigned to four groups: (A) control, (B) dihydrotachysterol at 16 mcg/kg/day, (C) 1,25-dihydroxyvitamin-D at 16 ng/kg/day and (D) vitamin D at 2000 IU/kg/day. The vitamin D or metabolites were fed by stomach tube daily. To duplicate the usual circumstances in the use of vitamin D and metabolites, aluminum hydroxide at 50 to 60 mg/kg/day in the feed, was provided to all groups except the control group. Twenty-four-hour urine and feces collections were obtained each day during the last three days of the 10-day balance studies.
Significant differences in serum calcium and phosphorus concentrations were not demonstrated. The means (SEM) of the excretions of calcium (UCa) and phosphate (Up) in mg/kg/day were:
Thus, the highest excretion of calcium occurred in the dihydrotachysterol group; the lowest occurred in the 1,25-dihydroxyvitamin D-treated group which was less than one-half that of the dihydrotachysterol group. Phosphate excretions showed no differences between the groups.
We conclude that with therapeutic doses of vitamin-D metabolites, hypercalciuria was not observed. Urinary calcium excretions were increased above that of control, except that of 1,25-dihydroxyvitamin D, which was lower.
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Jacob, M., Shelter, F., Chu, G. et al. 1606 VITAMIN D AND PHOSPHATE-BINDERS ON CALCIUM AND PHOSPHATE METABOLISM IN RATS. Pediatr Res 19, 378 (1985). https://doi.org/10.1203/00006450-198504000-01630
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DOI: https://doi.org/10.1203/00006450-198504000-01630