A tailored high-dose oral vitamin D supplementation safely allows a higher proportion of patients to achieve a normalized vitamin D level compared with a conventional regimen in patients with early breast cancer undergoing chemotherapy, a study published in the journal Annals of Oncology has shown.1
Because only a minority of patients with early breast cancer treated with adjuvant or neoadjuvant chemotherapy have sufficient baseline vitamin D levels, researchers sought to evaluate the efficacy and safety of a tailored high-dose oral vitamin D supplementation in normalizing serum vitamin D levels in this patient population.
For the phase 3 trial, researchers enrolled 195 patients with vitamin D deficiency and randomly assigned them 1:1 to receive a 6-month conventional vitamin D and calcium supplementation or a 6-month high-dose oral vitamin D regimen tailored to the individual deficiency plus a conventional calcium supplementation.
Results showed that only 68.4% of patients in the conventional arm and 67% of those in the tailored arm were compliant to the daily oral supplementation, with discontinuous high-dose vitamin D compliance appearing higher in the tailored arm.
Researchers found that 30% of patients in the tailored arm presented with a normalized vitamin D level compared with 12.6% in the conventional arm at 6 months (P = .003).
Furthermore, 52 patients who had not achieved vitamin D normalization after 6 months in the conventional arm switched to the tailored arm, and 44% of those patients achieved vitamin D level normalization.
In terms of safety, supplementation was well tolerated and researchers observed no significant differences in treatment-related toxicity between the 2 groups.
Although the tailored high-dose approach appears to be safe and effective, compliance to a daily oral supplementation regimen remains poor in this treatment setting
1. Jacot W, Firmin N, Roca L, et al. Impact of a tailored oral vitamin D supplementation regimen on serum 25-hydroxyvitamin D levels in early breast cancer patients: a randomized phase III study [published online ahead of print March 30, 2016]. Ann Oncol. doi:10.1093/annonc/mdw145.