[Hypovitaminosis D and biochemical parameters of bone metabolism in children with leukemia].

INTRODUCTION

25(OH)D is key for maintaining bone health. Treatment of pediatric patients with acute lymphoblastic leukemia (ALL) has a negative effect on bone metabolism.

OBJECTIVE

To describe the frequency of hypovitaminosis D, changes in serum 25(OH)D concentrations, and the biochemical and hormonal markers of bone metabolism between diagnosis and referral in children with ALL.

MATERIAL AND METHODS

Prospective, longitudinal, cohort study in pediatric patients (4-17 years) with newly diagnosed B-cell ALL, and without treatment. Patients were summoned under fasting conditions, and a peripheral blood sample was taken to determine 25(OH)D, parathyroid hormone (PTH), phosphorus, and ionic calcium concentrations.

RESULTS

Of the 40 patients recruited, 7 were lost to follow-up, so only 33 were analyzed. 91% of the children had hypovitaminosis D. We observed a significant increase in ionic calcium concentrations from baseline levels (1.1 mmol/L vs. 1.2 mmol/L, p = 0.002). Analysis of the Δ of serum PTH and 25(OH)D concentrations showed an inverse relationship (rho = -0.397, p = 0.024).

CONCLUSIONS

These findings confirm a high frequency of hypovitaminosis D. Low 25(OH)D levels may compromise calcium absorption and generate a compensatory increase in PTH.