Severity of Vitamin D Deficiency in Children with Nephrotic Syndrome: A Study from Tertiary Care Center in Northern India

Abstract

In nephrotic syndrome (NS) due to podocytopathies, loss of vitamin D binding globulin along with albumin in urine leads to Vitamin D deficient state. We aimed to study the severity of vitamin D deficiency and its clinical correlation in children with NS. We performed a cross-sectional study at a tertiary care hospital in Northern India. Enrolment of children aged 1-18 years was done. Patient's detailed history, numbers of relapse, treatment details, and data regarding various immunomodulatory drugs treatment. Vitamin D level was estimated, and its status was further classified as deficiency <20 ng/mL and insufficiency 20-30 ng/mL as per Global Consensus Recommendations on evaluation, treatment, and prevention of vitamin D deficiency. Continuous variables were compared using tests such as unpaired t-test, Kruskal-Wallis test, and Wilcoxon rank sum test depending on the distribution of parameters. Categorical variables were compared using Chi-squared tests or Fisher's exact test. A total of 96 children with NS were screened, of which 77.1% had vitamin D deficiency. The mean serum vitamin D level was 14.393 ± 8.52 ng/mL. Among the 48 children of the first episode of NS 36 were deficient (36/48 = 75%). Whereas in the relapse category, 30 patients had infrequently relapsing NS (deficient 24/30 = 80%). Eleven children had frequently relapsing NS; among them, 10 were vitamin D deficient (10/11 = 90.9%), and there was a negative correlation between vitamin D level and duration of illness. Vitamin D deficiency is a common comorbidity in children with NS. Given the putative immunomodulatory property of vitamin D, this deficiency should be identified and treated routinely in all cases of NS.