Obesity attenuates serum 25-hydroxyvitamin D response to cholecalciferol therapy in critically ill patients

Abstract Objectives The presence of obesity may confound cholecalciferol dosing in vitamin D–deficient patients owing to potentially decreased bioavailability. The aim of this retrospective study was to evaluate cholecalciferol therapy in vitamin D-deficient, critically ill trauma patients with and without obesity. Methods Adult patients with severe traumatic injuries who had a serum 25-hydroxyvitamin D (25-OH vit D) 1.32 mmol/L). Fifty-three patients (18 obese, 35 non-obese) were identified for study. Results Despite similar baseline concentrations (36 ± 7 versus 37 ± 7 nmol/L; P  = NS), 25-OH vit D response was attenuated for those with obesity after 1 and 2 wk of cholecalciferol therapy (51 ± 18 versus 66 ± 27nmol/L, P P Conclusion Obesity alters the response to cholecalciferol therapy in critically ill patients with severe traumatic injuries.