Randomized phase 2 trial of high-dose vitamin D to attenuate bone loss with androgen deprivation therapy for prostate cancer

Androgen deprivation therapy (ADT) inhibits prostate cancer growth, but may also cause loss of bone mineral density (BMC) and increased fracture risk. Effective interventions for ADT-induced bone loss are limited. A phase 2 trial randomized prostate cancer patients receiving ADT and calcium to high-dose vitamin D (HDVD; 50,000 IU per week) or placebo for 24 weeks. After the intervention the HDVD group had lost an average of 1.5% of BMD at the total hip and 1.7% of BMD at the femoral neck; the placebo group had lost 4.1% and 4.4%, respectively. Among patients with low baseline 25-hydroxyvitamin D levels (<27 ng/ml), the BMD loss at the total hip was 2.3% in the HDVD group versus 7.1% in the placebo group. There were no differences between the groups in adverse events. The authors conclude that HDVD supplementation significantly reduced hip and femoral neck BMD loss, especially among patients with low baseline serum 25-hydroxyvitamin D levels.