An investigation of men undergoing surgery to remove a cancerous prostate shows there is a link between low levels of vitamin D and aggressiveness of disease.
The study – led by Northwestern University of Evanston, IL – is published in the Journal of Clinical Oncology.
The finding offers useful information for cases where patients have agreed with their doctor that the treatment should be “watchful waiting” for the time being rather than removal of the prostate or some other medical procedure.
Lead investigator Adam Murphy, an assistant professor of urology, says:
“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. Then a deficiency should be corrected with supplements.”
Researchers have found a link between low vitamin D and aggressive prostate cancer before, but those studies were based on blood that was sampled well before treatment.
The new study correlates vitamin D in blood sampled a couple of months before surgery to remove the prostate – radical prostatectomy – with an assessment of disease aggressiveness at time of surgery.
The link may explain some disparities seen in prostate cancer in different groups of men – for example in black men, says the team.
In previous investigations, Prof. Murphy and colleagues have found that black men who do not have much exposure to sunlight are up to 1.5 times more likely to be deficient in vitamin D than white men.