Vitamin D Supplementation in Pediatric Patients Undergoing Transplant: Room for Improvement

Abstract

Introduction Up to 70% of pediatric patients have low vitamin D (VD) levels prior to hematopoietic stem cell transplantation (HSCT). In addition to the known adverse effects of VD deficiency on bone health, studies have found that patients with VD deficiency before and at day +100 have significantly lower 1-year overall survival and increased mortality associated with graft-versus-host disease (GVHD). VD levels (VDL) 50ng/mL are optimal. Objectives The objective of this study was to assess practices for VD evaluation and VD supplementation (VDS), and to investigate the association between VDL and complications (GVHD, veno-occlusive disease [VOD]). This is one of the largest retrospective studies investigating standard of care practices for VD, and the association between VDL and complications in the pediatric population. Methods Patient records were abstracted for VDL through a retrospective chart review of patients that received HSCT at CHLA between January 2013 and April 2018. Overall survival (OS) time is defined as the time between HSCT and the time of death, from any cause. Those who remained alive were censored at the time of last contact. Results At the time of this interim review, 316 patients were identified, and baseline (BL) VDL were available for 135 patients. Of these, 61% had low BL VDL (33% deficient, 28% insufficient), and 39% had sufficient VDL (only 9% had optimal VDL). VDS was higher among those with insufficient or deficient BL VDL (p = 0.008). Only 16% patients achieved an optimal VDL during the HSCT process, regardless of supplementation status (figure 1). Nineteen had GVHD and 36 had VOD. There was no difference in demographics between those with and without BL VD assessments or between those who did and did not develop GVHD or VOD. GVHD and VOD incidence was higher in those with BL VD assessment than those without (p = 0.002 and p Conclusion We found that only 43% of patients had BL VDL assessed. Patients with insufficient or deficient VDL were significantly more likely to receive VDS, but still less than half received supplementation and only 16% ever had optimal VDL. There was no association between BL VDL or VDS and HSCT complications or survival, which is expected since such few patients achieved, and none sustained, optimal levels. This demonstrates that regular supplementation is not adequate to achieve or maintain the optimal VDL that are associated with improved outcomes. VD deficiency is a known and, importantly, modifiable risk factor that may be implicated in transplant outcomes. Further prospective studies are required to establish effective practices for monitoring and sustaining optimal VDL and to examine how this affects outcomes.