Vitamin D nutritional status and bone turnover markers in childhood acute lymphoblastic leukemia survivors: A PETALE...

The remarkable progress in the treatment of childhood acute lymphoblastic leukemia (cALL) has led to a survival rate reaching 90%. This success story is unfortunately linked to increased risk of impaired skeletal mass accumulation during childhood and adolescence, predisposing the patients to osteoporosis and pathological fractures at adulthood.

This study aims at characterizing the vitamin D status and bone health biomarkers in a well-characterized cohort of cALL survivors.

Food frequency questionnaires reveal that (i) the total vitamin D intake varies greatly (44-2132 IU/d), (ii) only 16.8% of the participants consume vitamin D supplements, and (iii) 74% of survivors' intakes are below the Recommended Daily Intakes (400 IU/d). For the 42 participants taking vitamin D supplements, the median (2.5-97.5^%iles) intake is 600 IU/d (21.2-1972 IU/d). Sixteen participants are vitamin D deficient (<30 nM) and 66 insufficient (≥30 - <50 nM). Serum 24,25(OH)₂D₃ concentrations are directly related to those of 25OHD₃, and those of 3-epi-25OHD₃ below the Lower Limit of Quantification in most samples. The participants' serum concentrations of cross-linked C-telopeptide of type-I collagen and intact amino-terminal pro-peptide of type-I collagen decrease steadily with age, leveling at adulthood, and are at all times higher in males.

The present study shows that the prevalence of vitamin D insufficiency or deficiency is not greater in cALL survivors compared to the general Canadian population despite low vitamin D food and supplement intakes. Furthermore, there seem to be no overt imbalance in the gender- and age-adjusted serum bone turnover marker concentrations.