Calcium and vitamin D supplementation in children with frequently relapsing and steroid-dependent nephrotic syndrome

Abstract

Background Children with frequently relapsing and steroiddependent nephrotic syndrome (FRNS/SDNS) are at risk for osteoporosis due to impaired metabolism of calcium and vitamin D. Objective To determine the effect of calcium and vitamin D supplementation on bone mineral density, serum ionized calcium levels and serum 25-hydroxy-vitamin D levels in children with FRNS and SDNS. Methods A clinical trial with a before and after design was performed. Subjects were SDNS or FRNS pediatric patients 2: 5 years of age. Subjects received 800 mg elemental calcium and 400 IU vitamin D supplementation for 8 weeks. Serum ionized calcium, serum 25-hydroxy-vitamin D [25(0H)D], and bone mineral density (BMD) were determined before and after the supplementation. Results Of the 30 subjects, 28 completed the study. However, only 20 subjects underwent BMD determination before and after supplementation. Of the 28 subjects, 22 had hypocalcemia and 26 had low vitamin D levels. Osteopenia was found in 14/20 subjects and osteoporosis was in 2/20 subjects. After 8 weeks of supplementation, mean serum ionized calcium increased from low [1.15 mmol/L (SD O.oJ)] to normal [1.18 mmol/L (SD 0.04)] (P< 0.001) levels, but mean serum 25(0H)D only increased from vitamin D deficiency category [20 ng/mL (SD 7 .7)] to vitamin D insufficiency category [25.5 ng/mL (7.7)] (P=0.010). Mean z-score BMD increased from -1.1 (SD 0.9) to -0.7 (SD 0.2) after supplementation (P<0.001). Conclusion Calcium vitamin D supplementation effectively increased serum ionized calcium, serum 25 (OH)D, and BMD in subjects with FRNS and SDNS. [Paediatr lndones. 2012;52:16-21].

Keywords

• frequent relapse nephrotic syndrome
• steroid dependent
• supplementation
• calcium
• vitamin D
• bone mineral density
• osteoporosis