The role of serum phosphorus (P) in the pathogenesis of absorptive hypercalciuria was assessed in 56 patients by an examination of serum P, renal phosphate threshold (TmP), and serum 1α,25-dihydroxyvitamin D [1α,25-(OH)2D]. Serum P and TmP were in the lower part of the normal range during outpatient evaluation (P intake 800-1,500 mg/day), but rose significantly during 3 days of hospitalization on a constant P intake (800 mg/day), while serum 1α,25-(OH)2D remained essentially unchanged. There was no correlation between serum P or TmP with serum 1α,25-(OH)2D, intestinal calcium (Ca) absorption, fasting urinary Ca, urinary hydroxyproline, or bone density. Orthophosphate therapy did not significantly change serum P, TmP, or serum 1α,25(OH)2D after 1 month of treatment, but these parameters were significantly decreased by 2-4 months of therapy. Despite the fall in serum 1α,25-(OH)2D concentration, the intestinal absorption of Ca remained elevated. The results do not support a major pathogenetic role for serum P in absorptive hypercalciuria.
|Original language||English (US)|
|Number of pages||8|
|Journal||Mineral and Electrolyte Metabolism|
|State||Published - Jan 1 1979|
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism