Background: Vitamin D (25-OHD) has a role in bone health after treatment for cancer. 25-OHD deficiency has been associated with risk factors for cardiovascular disease, but no data focusing on this topic in childhood cancer survivors have been published. We investigated the 25-OHD status in children treated for acute lymphoblastic leukemia (ALL), and evaluated its influence on vascular function.

Methods: 25-OHD levels were evaluated in 52 ALL survivors and 40 matched healthy controls. Patients were grouped according to 25-OHD level (< 20 ng/m or ≥ 20 ng/mL). Auxological parameters, biochemical and hemostatic markers of endothelial function (AD, HMW-AD, ET-1, vWFAg, TAT, D-dimers, Fbg, and hs-CRP), ultrasound markers of vascular endothelial function (flow-mediated dilatation, FMD, common carotid intima-media thickness, C-IMT, and antero-posterior diameter of infra-renal abdominal aorta, APAO) were evaluated in the patients.

Results: Cases showed higher prevalence of 25-OHD deficiency than controls (P = 0.002). In univariate analysis via mean comparisons, 25-OHD deficient (< 20 ng/mL) patients showed higher C-IMT values compared to the 25-OHD non-deficient (≥ 20 ng/mL) group (P = 0.023). Significant differences were also found for ET-1 (P = 0.035) and AD-HMW (P = 0.015). In the multiple regression models controlling for some confounders, 25-OHD still was associated with C-IMT (P = 0.0163), ET-1 (P = 0.0077), and AD-HMW (P = 0.0008).