The prevalence of Vitamin D deficiency is higher in adult survivors of childhood cancer.

It is unclear whether the rate of vitamin D deficiency in paediatric cancer survivors is higher than in the background population, and whether this is of pathological significance. 25OHD was measured in a previously studied group of 208 survivors (n = 108 paediatric 5-17 years, n = 99 adults 18-39 years) and compared with paediatric (5-17 years; n = 132) and adult controls (25-35 years; n = 1393 from the AusDiab cohort) adjusted for age and gender. Relationships with treatment factors (irradiation, bone marrow transplantation and intensity of treatment) along with overweight/obesity (defined by BMI), abdominal adiposity (waist:height ratio >0·5) and hyperinsulinism or abnormal glucose tolerance (HI/aGT) were sought. 25OHD concentrations were similar in paediatric survivors compared with controls (64·3 ± 21·6 nmol/l vs 66·3 ± 22·8 nmol/l), with no effect of age or gender. Adjusted for gender, rates of 25OHD deficiency (<50 nmol/l) were higher in adult survivors compared with AusDiab controls (42·4% vs 20·8%; P < 0·001). Apart from time since diagnosis (P = 0·03), no relationship with treatment factors was detected. In multivariate regression analysis, abdominal adiposity (P = 0·001), but not overweight/obesity by BMI status nor HI/aGT, was associated with significantly lower 25OHD concentrations. Adult survivors are at increased risk of abnormalities in vitamin D compared to the background population, probably reflecting longer time since diagnosis. Like others, we have not identified any contributory treatment-related factors. Vitamin D deficiency does not appear to be associated with the development of abnormal glucose tolerance in this population.