Effect of calcium and vitamin D supplementation on serum calcium level in children with idiopathic nephrotic syndrome

Abstract

Background Patients with idiopathic nephrotic syndrome (NS) may
develop hypocalcemia caused by low levels of albumin and vitamin
D -binding protein, which subsequently decreases calcium absorption
in the intestine. Hypocalcemia may result in neuromuscular
manifestations, such as Chvostek's and Trosseau's signs.
Objectives To evaluate the effect of calcium and vitamin D
supplementation on hypocalcemia and its clinical manifestations
in idiopathic NS children.
Methods A randomized, single-blind, controlled trial was
performed in idiopathic NS patients aged 1-14 years. Subjects
were divided into treatment and placebo groups. Subjects in
the treatment group received 800 mg elemental calcium and
400 IU vitamin D supplementation, while they in control group
received placebo syrup, both for 8 weeks. Serum calcium and
manifestations of hypocalcemia were examined before and after
supplementation.
Results Thirty subjects completed the study (15 in each group).
Seventeen subjects experienced hypocalcemia. Chvostek's and
Trosseau's signs were observed in 6 subjects in the treatment group
and 2 subjects in the placebo group (P= 0.427). After 8 weeks of
intervention, Chvostek's and Trosseau's signs disappeared in both
groups, and calcium levels were significantly increased in both
groups compared to the levels before intervention. However, there
was no significant difference in serum calcium levels after 8 weeks
between the treatment and placebo groups (P =0.707).
Conclusion Normalization of serum calcium levels and improved
clinical manifestations ofhypocalcemia occur both in NS patients
who receive calcium and vitamin D supplementation and those
who do not.