Ionized calcium, 25-hydroxyvitamin D, and parathyroid hormone in children with steroid-sensitive nephrotic syndrome

Abstract

Background The chief complications of nephrotic syndrome (NS) are infections and thromboembolic events. Others include hypovolemic crisis, acute renal failure, and hormonal and mineral alterations. Objective The aim was to study the level of serum ionized calcium during the active stage and after remission in steroid-sensitive nephrotic syndrome (SSNS) patients and 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) during the active stage of the disease. Patients and methods The study was conducted on two groups. Twenty children with the first episode of SSNS were investigated and compared with 20 healthy children as a control group. Serum ionized calcium, serum 25(OH)D, PTH, phosphorus, and alkaline phosphatase were measured during the active stage of the disease and serum ionized calcium was repeated after remission. Results Children with active SSNS had low ionized calcium, low-serum 25 (OH)D levels, with high PTH and high phosphorus and low alkaline phosphatase levels compared with the control. All patients had 25(OH)D deficiency, of which, 80% were severely deficient. Both serum ionized calcium and 25(OH)D had a significant negative correlation with PTH (r=−0.655, P=0.002 and r=−0.575, P=0.008, respectively). Serum ionized calcium was negatively correlated to spot protein/creatinine ratio in urine (r=− 0.565, P=0.009). Levels of serum ionized calcium during the active stage of the disease were markedly lower than that after remission. However, both were significantly lower than the control group. Conclusion Children with SSNS are at risk of vitamin D deficiency and hypocalcemia, therefore, further research will be needed to prove the need for vitamin D supplementation to prevent the occurrence of possible complications.