High Dose Vitamin D Replacement in Patients Undergoing Hematopoietic Stem Cell Transplantation

Vitamin D deficiency is common in childhood and has been associated with increased incidence
of graft versus host disease (GVHD) and decreased survival in patients undergoing
hematopoietic stem cell transplantation (HSCT). Recently, quality improvement efforts to
correct serum vitamin D levels among inpatients at CCHMC who have already received HSCT and
who were vitamin D deficient suggest that current recommended doses of vitamin D are
inadequate to treat vitamin D deficiency. Possible hindrances to vitamin D treatment in the
HSCT population include malabsorption related to gut GVHD, mucositis, increased requirement
for calcium and/or vitamin D, kidney disease, liver disease, and infection. Single, high dose
vitamin D treatment (stoss-therapy) has been utilized effectively to treat rickets and other
chronic illnesses such as cystic fibrosis in children. The investigators hypothesize that
stoss-therapy provided orally prior to transplantation will result in rapid and sustained
correction of vitamin D deficiency in children who require HSCT. The investigators propose to
test the efficacy and safety of high dose vitamin D therapy among HSCT patients in a tiered,
step-wise manner (step one/two) in order to define treatment doses capable of providing
vitamin D sufficiency.

Inclusion Criteria:

- Step 1: Patients who are preparing for HSCT, 25OHD level (<50 ng/mL), and no prior
history of HSCT.

- Step 2: Patients who are preparing for HSCT 25OHD level (<50 ng/mL).

Exclusion Criteria (both Step 1 and Step 2):

- Patients with history of pathologic fractures,

- uncorrected hypocalcemia or hypophosphatemia,

- known history of nephrocalcinosis or nephrolithiasis,

- current granulomatous disease,

- those currently in ICU.