Serum Vitamin D levels in patients with chronic kidney disease.

INTRODUCTION

Hypovitaminosis D is reported to be associated with several medical complications. Recent studies have reported a high worldwide prevalence of Vitamin D deficiency in the general population (up to 80 %). This is even higher in patients with chronic kidney disease (CKD) and increases with advancing stages of CKD.

OBJECTIVES

To determine the difference in serum Vitamin D [25-hydroxyvitamin D, 25(OH) D] levels between CKD patients and normal healthy population.

MATERIALS AND METHODS

A prospective cross-sectional study involving 50 normal volunteers (control) and 50 patients with CKD stages 2-4. Their demographic profiles were recorded and blood samples taken for serum 25(OH) D, intact parathyroid hormone (iPTH) and other routine blood tests.

RESULTS

All subjects regardless of renal status had hypovitaminosis D (< 30ng/mL). The mean serum 25(OH) D were comparable in the control and CKD groups (15.3 ± 4.2 ng/mL vs 16.1 ± 6.2 ng/mL, p = NS). However, within the Vitamin D deficient group, the CKD group had lower levels of serum 25(OH) D [12.6(3.7) ng/mL vs 11.2(6.5) ng/mL, p = 0.039]. Female gender [OR 22.553; CI 95 % (2.16-235.48); p = 0.009] and diabetic status [OR 6.456; CI 95 % (1.144-36.433); p = 0.035] were independent predictors for 25(OH) D deficiency.

CONCLUSIONS

Vitamin D insufficiency and vitamin D deficiency are indeed prevalent and under-recognized. Although the vitamin D levels among the study subjects and their control are equally low, the CKD group had severe degree of vitamin D deficiency. Diabetic status and female gender were independent predictors of low serum 25(OH)D.