Prevalence of vitamin D insufficiency in survivors of childhood cancer

Abstract

Data on 25-hydroxyvitamin D (25-OH D) status among survivors of childhood cancer are limited. Our aim was to determine the prevalence of and risk factors for 25-OH D insufficiency in a large, diverse population of cancer survivors being followed in a childhood cancer survivor clinic. Retrospective chart review in survivors seen for routine long-term follow-up, who underwent routine screening blood studies including 25-OH D levels. Vitamin D insufficiency was defined as 25-OH D <20 ng/ml. Four hundred eighty-four subjects (234 males) were evaluable for this analysis. Median age at 25-OH D testing was 12.3 years (2.05-36.4) and median age at cancer diagnosis was 3.9 years (0-18). Diagnoses included brain tumors (23.6%), neuroblastoma (21%), and leukemia (17.6%). Mean 25-OH D level was 25.2 ng/ml (SD = 10.37); 29% of subjects were 25-OH D insufficient. In univariate analysis, race, pubertal status, and age at cancer diagnosis were associated with 25-OH D insufficiency (P < 0.05). In multivariate analysis, a model including race and pubertal status provided a good fit for the data. The prevalence of 25-OH D insufficiency in these cancer survivors was high but similar to what has been described in the general population. No cancer specific variables were associated with 25-OH D insufficiency. Since cancer survivors are at a higher risk for subsequent malignancies, cardiovascular disease, and low bone mineral density, all of which may be affected by 25-OH D levels, interventions to improve 25-OH D status in this vulnerable population are needed.