RESUMEN
BACKGROUND: Prevalent vitamin D deficiency (VDD) and low bone mineral density (BMD) have led to vitamin D supplementation for children with cancer, regardless vitamin D status. However, it remains unsettled whether this enhances bone strength. We sought to address this issue by carrying out a systematic review of the literature. METHODS: We conducted a literature search using PubMed, Embase, and Cochrane databases. Studies including children up to 5 years after cancer therapy were assessed for the association between 25-hydroxyvitamin D (25OHD) levels and BMD Z-scores or fractures, and the effect of vitamin D supplementation on BMD or fractures. Evidence quality was assessed using the GRADE methodology. RESULTS: Nineteen studies (16 observational and 3 interventional, mainly involving children with hematologic malignancies) were included. One study which analyzed 25OHD as a threshold variable (≤10 ng/ml) found a significant association between 25OHD levels and BMD Z-scores, while 25OHD as a continuous variable was not significantly associated with BMD Z-scores in 14 observational studies. We found neither a significant association between lower 25OHD levels and fractures (2 studies), nor between vitamin D (and calcium) supplementation and BMD or fracture frequency (3 studies) (very low quality evidence). CONCLUSION: There is a lack of evidence for an effect of vitamin D (and calcium) supplementation on BMD or fractures in children with cancer. Further research is needed; until then, we recommend dietary vitamin D/calcium intake in keeping with standard national guidelines, and periodic 25OHD monitoring to detect levels <20 ng/ml. Vitamin D/calcium supplementation is recommended in children with low levels, to maintain levels ≥20 ng/ml year-long.
Asunto(s)
Densidad Ósea , Fracturas Óseas/prevención & control , Neoplasias Hematológicas , Neoplasias , Deficiencia de Vitamina D/terapia , Vitamina D/análogos & derivados , Vitaminas/administración & dosificación , Adolescente , Calcio de la Dieta/administración & dosificación , Supervivientes de Cáncer , Niño , Preescolar , Consenso , Fracturas Óseas/sangre , Fracturas Óseas/etiología , Neoplasias Hematológicas/sangre , Neoplasias Hematológicas/complicaciones , Neoplasias Hematológicas/terapia , Humanos , Neoplasias/sangre , Neoplasias/complicaciones , Neoplasias/terapia , Estudios Observacionales como Asunto , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangre , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Ensayos Clínicos Controlados Aleatorios como Asunto , Vitamina D/administración & dosificación , Vitamina D/sangre , Deficiencia de Vitamina D/complicacionesRESUMEN
As increasing numbers of childhood cancer patients are surviving, the long-term complications of the disease and its treatment have become ever more increasingly important. Reduced bone mineral density and increased fracture risk have been reported during and after treatment of children with cancer. The causes of osteoporosis are multifactorial. Among others, the disease itself, chemotherapy, irradiation and genetic susceptibility play a role. Bone mineral density in later life depends largely on the peak bone mass achieved in adolescence or young adulthood. Therefore, optimizing peak bone mass is of clinical importance. Preventive and therapeutic strategies, such as calcium and vitamin D supplementation, physical activity and bisphosphonates, are considered.