"After you load the body with vitamin D and ... you keep on giving the same dose, the body just maintains the levels," he said.
Dr. Khan said that additional studies are needed to address long-term sustainability, and that the investigators have proposed a trial to the Southwest Oncology Group for the same intervention for 1-2 years to study a longer-term effect.
Dr. Khan reports honoraria from Abraxis BioScience and Genentech, and research funding from Abraxis and Novartis Roche/Genentech. His coauthors and Dr. Mustian report no disclosures.