Little is known about serum vitamin D levels following hematopoietic cell transplantation (HCT). Patients are instructed to avoid sun exposure because of an increased risk of skin cancers. Altered gastrointestinal absorptive capacity as a result of GVHD, bile acid or pancreatic enzyme insufficiency or bacterial overgrowth may lead to difficulty in absorbing the fat-soluble vitamin D. This study was undertaken to determine the prevalence of serum 25-hydroxyvitamin D (25(OH)D) deficiency, and factors associated with 25(OH)D deficiency, among children and adults who were at least 1 year following HCT. A total of 95 participants (54 males and 41 females) completed a questionnaire on usual diet and lifestyle, and provided a blood sample for 25(OH)D determinations between November 2008 and July 2009. The majority of participants had serum 25(OH)D levels ≥75 nmol/L (n=62, 65%), 23 had insufficient levels (50-75 nmol/L) and 10 participants were deficient (<50 nmol/L). The majority of participants reported regular use of vitamin D supplements (n=58, 61%). Prednisone use was significantly inversely associated with serum 25(OH)D concentrations. Total vitamin D intake was the strongest single predictor of 25(OH)D concentrations. These findings suggest that 400-600 IU vitamin D per day appears to be required to achieve optimal serum 25(OH)D concentrations following HCT.
Bibliographical noteFunding Information:
The authors would like to thank Roberta Nicklow, RN for her assistance in initiating this study, and Todd DeFor, MS for abstraction of relevant data from the University of Minnesota clinical HCT database. The National Cancer Institute (R21 CA135180) and The Children’s Cancer Research Fund.
- cancer survivors
- dietary supplements
- hematopoietic cell transplantation
- serum 25(OH)D
- vitamin D