Ultra-high Dose Vitamin D for HSCT

Up to 70% of patients have vitamin D deficiency prior to hematopoietic stem cell transplant (HSCT). Patients with sufficient Vitamin D levels (\>50nm/L) prior to allogeneic transplant have significantly better overall survival (OS) and lower rates of rejection and relapse. Vitamin D inhibits Th1 and augments Th2 cell development. Patients who receive vitamin D supplementation during allogeneic transplant have less inflammatory-mediated processes such as chronic graft versus host disease (GVHD) and lower levels of naïve CD8+ cells and CD40 ligand. Multiple studies have raised concern regarding the adequacy of standard and high-dose vitamin D dosing for vitamin D deficiency. A single oral ultra-high dose of Vitamin D given prior to HSCT has been shown to be a safe and well tolerated method of sustaining therapeutic Vitamin D levels for 6-19 weeks. This is a pilot study to investigate the dynamic changes in inflammatory biomarkers following ultra-high-dose vitamin D supplementation. The study population is patients with total vitamin D level \</=50ng/mL prior to HSCT.