A recent 2016 editorial review explored the race disparities among African American (AA) men and the incidence of having higher rates along with higher mortality rates of aggressive prostate cancer and why a deficiency of vitamin D may be part of the explanation of this discrepancy. According to the Prostate Cancer Foundation, African American men are 64% more likely to develop prostate cancer compared with Caucasian men and are nearly 2.4 times more likely to die from the disease.
“The statistics on African American men and prostate cancer are disturbing,” said Dr. David Samadi. “Genetics can certainly play a role in this discrepancy along with environmental factors such as diet and lifestyle. At this point, the exact relationship between prostate cancer and genetics remains unclear but if a deficiency of vitamin D is a possibility for the disproportionate rate of prostate cancer between African American men and other ethnicities, then this needs to be researched more thoroughly.”
The review looked at several various studies over the years, some providing limited support for low circulating levels of vitamin D being associated with an increased risk of advanced aggressive prostate cancer and mortality. Men with vitamin D deficiency is defined as a 25 hydroxyvitamin D (25(OH)D) level below 20 ng/ml. But of these studies, most epidemiology research of vitamin D and aggressive prostate cancer has been conducted among men of European ancestry who have lighter skin pigmentation along with a higher vitamin D intake and supplement use. These same men also had sufficient levels of circulating 25(OH)D levels of vitamin D – 30 ng/ml or higher.
A recent cross-sectional study conducted in Chicago that was reviewed, demonstrated that serum 25(OH)D levels predicted biopsy outcomes in vitamin D deficient AAs and European Americans (EAs). Approximately 1,760 men who underwent a prostate biopsy (26.7% were AAs), those who had low serum vitamin D levels (25(OH) D), had higher rates of adverse pathology. These findings also showed that of the AA men in this study, a large number of them were vitamin D deficient. This may have to do with darker skinned individuals living in high latitude regions having insufficient levels of ultraviolet rays for cutaneous vitamin D synthesis for only certain times of the year along with insufficient food sources and dietary supplements containing vitamin D.
Other studies have shown that vitamin D supplementation of 4000 IU/day for two months can effectively raise serum 25(OH)D levels eliminating disparities in serum vitamin D levels among AAs and EAs. After two months of supplementation, the patients underwent radical prostatectomy and gene expression profiles of nonmalignant prostate tissue were evaluated with RNA-sequencing. The finding showed genes involved in immune response and inflammation were differentially expressed between AA and EA men.
African American men who are vitamin D deficient may also see improved clinical outcomes when utilizing vitamin D supplementation. A trial showed that after one year of supplementation more than half of the patients had improved clinical characteristics and 55% had decreased number of positive cores or lower Gleason scores at repeat biopsy after one year.
“More evidence is showing that sufficient vitamin D intake appears to reduce aggressive prostate cancer and likely increases survival rates,” stated Dr. Samadi. “Even short-term vitamin D supplementation may at least reduce the disparity of prostate cancer rates between African American and other men. There are still many questions needing to be addressed but for now using vitamin D supplementation as a therapeutic dose for reducing prostate cancer rates among African American men is a viable option.”
Patients newly diagnosed with prostate cancer can contact world renowned prostate cancer surgeon and urologic oncologist, Dr. David Samadi, for a free phone consultation and to learn more about prostate cancer risk, call 212-365-5000 or visiting prostatecancer911.com.