Calcium and Phosphate Homeostasis in Patients with Recurrent Nephrolithiasis

Objectives: The aim of the study was to evaluate the Calcium (Ca) and Phosphate (Ph) homeostasis and their association with plasma 25(OH)2 vitamin D3 (VitD3) and parathyroid hormone (PTH) in patients with recurrent nephrolithiasis. Methods: A cross-sectional, involved 100 confirmed patients with renal stone (RS).Their serum levels of Ca, PTH, Ph, and VitD3 had assessed. Biochemical analysis of renal calculi and crystals had been investigated also. The summary measures had described as mean+/-SD for continuous variables and frequencies/percentage for nominal variables. The mean serum Ca, Ph, PTH, and VitD3 were (8.01 +/- 2.2 mg/dl, 2.9 +/- 1.2 mg/dl, 56.7 +/- 24.7 pg/dl, and 7.03 +/- 4.2 pg/ml), respectively. Results: Almost all patients (97%) had a positive history of previous RS with a predominant family history in most instances (82%). There was a positive non-significant correlation between VitD3 with serum Ph and Ca. Whereas an inverse non-significant correlation between PTH with serum Ca and VitD3 had observed. Urinary crystals analysis revealed that uric acid represented 53% of the total crystals, followed by Ca-oxalate. Stone analyses revealed that around 3/4th of the cases had Ca-oxalate stone, followed by Ca-oxalate with uric acid, then Ca-phosphate, and the least type was mixed stone types. Conclusion: There was a positive non-significant correlation between VitD3 with serum Ph and Ca. There was an inverse non-significant correlation between PTH with serum Ca and VitD3. Serum Ca, and Ph were non-significant predictors of renal stones and/or urinary crystals.