Low 25(OH) Vitamin-D levels are associated with inferior graft function in living related kidney transplant recipients

Introduction: Vitamin D deficiency can impact post-transplant outcomes due to its effect on graft function and rejection. The effect of pre- and post-transplant serum vitamin D levels was evaluated on graft function. Objectives: This study aims to determine the incidence of vitamin D deficiency and its effect on post kidney transplant allograft function in a North Indian cohort. Patients and Methods: We evaluated 57 patients on dialysis, going for transplantation. Estimated glomerular filtration rate (eGFR) was measured using modification of diet in renal disease (MDRD) formula at 2 weeks and 3, 6, 12 months interval after kidney transplantation. Results: Pre- and post-transplant (3 months) vitamin D levels were evaluated for vitamin D deficiency and graft function. Before transplant vitamin D levels were 25.77 ± 13.68 ng/mL, 40.4% of these recipients had vitamin D deficiency (levels <20 ng/mL). After transplant, vitamin D levels at 3 months were 22.08 ± 11.15 ng/mL and 54.4% of recipients had vitamin D deficiency. No patient was on vitamin D supplementation after transplantation. At 3 months post-transplant, recipients with vitamin D levels <20 ng/mL, had significantly lower eGFR and higher serum creatinine value as compared to the group with vitamin D levels >20ng/mL. Recipients were divided into 3 groups based on pre- and post-transplant vitamin D levels (<20, 20-30 and >30ng/mL). Pre-transplant vitamin D levels correlated with graft function at 14 days. On multiple regression analysis, 3-month post-transplant vitamin D levels correlated with 12 months eGFR. There was increased incidence of acute rejection episodes in vitamin D deficiency group. Conclusion: There is a high incidence of vitamin D deficiency and insufficiency in kidney transplant recipients. Low levels of post-transplant vitamin D levels at 3 months were associated with inferior allograft function (eGFR) at 1 year.