Prostate cancer, which occurs in the small gland that produces the seminal fluid that transports and nourishes the sperm, is among the most common types of cancer affecting men. Now, a new study suggests that having low levels of vitamin D may indicate a more aggressive form of this cancer.
For the study, which was published in the Journal of Clinical Oncology, researchers involved 190 men whose prostates were removed because of cancer. Of these participants, nearly 46 percent had more aggressive prostate cancer and a significant number of these were diagnosed with vitamin D deficiency prior to undergoing surgery.
Based on the result, the researchers said that low vitamin D level can serve as a good indicator of aggressive prostate cancer. The findings may also help men and their doctors monitor cancer instead of opting to remove the prostate, a practice called active surveillance.
Study researcher Adam Murphy, from Northwestern University Feinberg School of Medicine, said that vitamin D deficiency is a biomarker that can predict aggressive prostate cancer. He recommends that vulnerable men get tested for vitamin D deficiency.
"Men with dark skin, low vitamin D intake or low sun exposure should be tested for vitamin D deficiency when they are diagnosed with an elevated PSA or prostate cancer," Murphy said. "Then a deficiency should be corrected with supplements."
Although earlier studies have already shown a link between vitamin D levels and aggressive forms of prostate cancer, these were based on bloods that were drawn prior to treatment.
The new study offers a more direct correlation between the prostate cancer and vitamin D as it measured the vitamin D levels a couple of months before the tumor was identified as aggressive during the surgical removal of the prostate.
The identified association between vitamin D and prostate cancer may also help explain the disparities observed in prostate cancer.
Earlier research has shown that African men who live in low sunlight locations have up to 1.5 increased risks for vitamin D deficiency compared with Caucasian men. Men who lack exposure to sun and those who have dark skin are considered vulnerable to prostate cancer.
"Insufficiency/deficiency of serum 25-OH D is associated with increased odds of adverse pathology in men with localized disease undergoing radical prostatectomy," the researchers wrote in their study. "Serum 25-OH D may serve as a useful biomarker in prostate cancer aggressiveness, which deserves continued study."