Retrospective Analysis on the Effect of Vitamin D Intake and Supplementation on Bone Mineral Density in Pediatric Leukemia Patients who underwent Allogeneic Bone Marrow Transplantation

Abstract

Children treated for leukemia with bone marrow transplant (BMT) are exposed to multiple risk factors that have been shown to have direct or secondary effects on vitamin D serum levels and subsequently, bone mineral density (BMD). Vitamin D insufficiency/deficiency has been associated with low bone mass and increased fracture rates in both adult and pediatric BMT recipients. The influence that dietary and supplemental vitamin D intake has on reducing BMD deficits in this specific patient population remains unclear. Our group retrospectively analyzed electronic medical record (EMR) and hard copy data from a population of leukemia survivors who underwent BMT at the UCSF Benioff Children's Hospital, Oakland, over the span of three years post transplantation. Vitamin D intake and serum levels in addition to other dietary, medication, and clinical factors that may have impacted long‐term bone health in this population were analyzed. Preliminary results show that prior to transplantation mean total vitamin D intake did not meet the DRI of 15 mcg/day (12.3 ± 3.2) but was satisfied post BMT, largely due to supplement intake. The total intake of vitamin D greatly increased over time but this observation was not found to be significant (p=0.077). Mean serum vitamin D levels also increased over time, although this was not found to be significant (p=0.187). Spine BMD, Z‐scores and whole body BMD Z‐scores did not significantly change over time, however, whole body BMD did significantly increase over time (p=0.039). Spine BMD was found to have a moderate negative correlation with supplemental vitamin D intake (−0.576 / p=0.0017) at all time points. Spine BMD Z‐scores were found to have a moderate negative correlation with dietary vitamin D intake (−0.477 / p=0.012) at all time points. Whole body BMD Z‐scores were found to have a moderate negative correlation with total vitamin D (diet and supplement) intake (−0.381 / p=0.042) at all time points. Our preliminary analyses investigated single variables over time and suggest that changes in BMD may be attributed to multiple factors such as varied dietary intakes, extent of supplementation, and patient baseline characteristics. More in depth statistical modeling to investigate possible interactions between identified dietary, medication, and clinical variables that can impact BMD will provide a more accurate representation of potential causes and possible solutions in addressing the bone health of this at risk pediatric patient population.