Vitamin D Supplementation in Glomerular Disease

Inclusion Criteria: * Males or females, age 5-30 years * Diagnosis of primary glomerular disease (such as steroid-resistant nephrotic syndrome, minimal change disease, FSGS, membranous nephropathy, membranoprolfierative glomerulonephritis, and Immunoglobulin A \[IgA\] nephropathy) without systemic inflammatory disorders (i.e. lupus, vasculitis) * Serum 25(OH)D level \<30 ng/ml and urine protein:creatinine ratio ≥0.5 at Screening Visit. Exclusion Criteria: * Pregnancy * estimated Glomerular Filtration Rate (eGFR) \<30 ml/min/1.73m2 at Screening Visit * Serum phosphorus \> 5.5 mg/dl or hypercalcemia * Chronic medical conditions or medications unrelated to the renal disease that may impact vitamin D status * Known history of kidney stone(s)