Prevalence of vitamin D deficiency in children with hemato-oncological diseases at a tertiary hospital in Buenos Aires.

Hypovitaminosis D (HD) is a relevant deficit. This vitamin has implications in bone health, as well as immunological and metabolic functions, and in the pathophysiology of cancer. Pediatric oncology patients are at increased risk for this deficiency. A cross-sectional, retrospective study was conducted to determine the prevalence of HD in pediatric oncology patients in a high-complexity hospital between January 2019 and August 2023. Eighty-nine patients were included. The overall median vitamin D levels were 18.3 ng/mL (IQR: 11.1-26.7). The prevalence of HD was 52.8% (95%CI: 41.9-63.5). These results indicate that, in this sample, more than half of pediatric oncology patients present HD. We emphasize the importance of determining the levels of this vitamin at diagnosis and during treatment of the disease in this highly vulnerable group.