Vitamin D and prostate cancer: Higher intake improves active surveillance outcomes

Prostate cancer will affect 1 in 6 men. However, the disease will be fatal in only 1 in 36, due to its potential for slow growth.¹ Urologists often monitor the slower, low-risk cases to determine which will evolve into more significant and aggressive disease. Instead of treating the disease in low-risk patients, they practice active surveillance. In an interview with Oncology Nurse Advisor, Bruce W. Hollis, PhD, professor of Pediatrics, Biochemistry, and Molecular Biology, and director of Pediatric Nutritional Sciences at the Medical University of South Carolina, explained, “The cure—meaning surgery or radiation—is probably worse than the disease, so they wait a year and then do another biopsy to see where the patient stands.”

Prostate cancer’s characteristic latency makes it the perfect model for longitudinal research, and that is exactly what Hollis and his group conducted over an extended period of time. Their pilot study evaluated the effects of enhancing vitamin D status and the subsequent related changes in prostate cancer tumor progression in a significant number of subjects over 1 year. A secondary objective was to compare prostate gland changes from a molecular standpoint before and after treatment with vitamin D₃ for a period of 2 months for men who had chosen surgery over active surveillance. They presented their results at a meeting of the American Chemical Society in March 2015.²

The active surveillance arm of the study included 132 participants; mean age was 65.5 years. These men demonstrated a significant reduction of disease, as assessed via year-to-year prostate biopsy, compared with historical controls. However, PSA levels showed no difference by treatment. Men who elected to undergo prostatectomy 2 months after biopsy and were treated with vitamin D₃, demonstrated biochemical and molecular changes consistent with a decrease in inflammatory processes compared with men who did not receive vitamin D₃. 

After 1 year, more than half of the participants in the active surveillance group demonstrated improvement on the vitamin D regimen, as shown by a decreased number of positive cores at repeat biopsy. The group concluded that men with low-risk prostate cancer who are undergoing active surveillance might derive benefit from taking 4,000 IU of vitamin D₃ per day, without experiencing side effects from the treatment. A randomized trial is currently underway to further explore these observations. Hollis said that vitamin D is now widely used in the urology service at the Medical University of South Carolina, demonstrating how the studies have impacted clinical practice.