Prevalence of Vitamin D deficiency among patients after kidney transplantation in Latvia

Nutritional Vitamin D deficiency is an increasingly recognised condition in chronic kidney disease patients and in patients after kidney transplantation. The main goal of the present study was to estimate the prevalence of hypovitaminosis D in the cohort of kidney grafted patients in Latvia and to determine the relationships between vitamin D level and kidney graft function, time since transplantation, gender, use of particular immunosuppressive medications, and some biochemical parameters. We measured the 25(OH)D serum level in 165 patients. Mean age of patients was 49.7 years (range: 11-80). Median time after transplantation was 6.5 years (range 0.8-16.4 years). Mean 25(OH)D level for all cohort was 22.71 ± 7.06 ng/mL; only 30/165 (18%) of patients were vitamin D sufficient. 71/165 (43%) patients showed insufficient 25(OH)D level, 62/165 (38%) patients were mildly vitamin D deficient, and 2/165 (1%) were severely vitamin D deficient. Serum creatinine level was negatively correlated with 25(OH)D (r = -0.21; P < 0.01). We also observed an inverse correlation between iPTH and 25(OH) D (r = -0.35, P < 0.0001) and between total alkaline phosphatase and 25(OH) D (r = -0.20, P < 0.01). This study confirmed the almost universal prevalence of vitamin D insufficiency among kidney graft recipients and emphasized importance of regular evaluation and proper supplementation of Vitamin D in this population.