Serum vitamin D levels among immunoglobulin A nephropathy patients and the associated parameters

INTRODUCTION: Low serum 25-hydroxyvitamin D is associated with chronic kidney disease progression, and there are limited data on the vitamin D levels in patients with Immunoglobulin A nephropathy. This study was conducted to determine the level of 25-hydroxyvitamin D in a stable immunoglobulin A nephropathy patient and its association with other parameters.

MATERIALS AND METHODS: We performed a cross-sectional study involving 70 patients with biopsy-proven immunoglobulin A nephropathy with a stable estimated glomerular filtration rate and urinary albuminuria. Their demographic profiles were documented, and blood samples were taken for serum 25-hydroxyvitamin D, highly sensitive C-reactive protein, urine albuminuria and other routine blood tests.

RESULTS: We found nine patients (12.9%) had sufficient 25- hydroxyvitamin D [25(OH)D] levels of more than 30ng/mL and the rest of the patients; 61 (87.1%) had serum 25(OH)D levels below 30 ng/ml. Amongst those with low vitamin D, 38 (62.3%) had serum 25(OH)D between 15-30 ng/mL (insufficient), and the remaining 23 (37.7%) had serum 25(OH)D below 15 ng/ml (deficient). Their mean level of serum 25(OH)D was 19.92 ± 9.04 ng/mL with a serum creatinine of 106.23 ± 38.56 μmol/L and mean estimated glomerular filtration rate (eGFR) at 68.11± 27.65 mL/min/1.73 m2. There was no association between urinary albuminuria, highly sensitive C-reactive protein, estimated glomerular filtration rate or systolic blood pressure with serum 25(OH)D level.

CONCLUSION: Low vitamin D (insufficiency and deficiency) are indeed prevalent in stable immunoglobulin A nephropathy patients. We found no correlation between the vitamin D levels with albuminuria, renal function and highly sensitive C-reactive.