Several studies over the years indicate that doctors should test men with prostate cancer at the time of diagnosis to determine vitamin D levels. That’s because low levels of this vitamin may herald a worse prognosis.
Vitamin D Levels in Men with Prostate Cancer:
The researchers at Northwestern University School of Medicine collected information on the blood level of 25-hydroxyvitamin D in men scheduled for prostate surgery. (That is the most useful measurement of vitamin D in the body.) Those with the lowest levels of vitamin D were more likely to have aggressive prostate cancers with high Gleason scores (Journal of Clinical Oncology, April 20, 2016). Gleason scores classify the stage of prostate cancer, with higher scores being more serious.
There were 190 men in the study with an average age of 64. Those who had aggressive prostate tumors had a median 25-hydroxyvitamin D level of 22.7 nanograms/milliliter. A level of 30 ng/ml is more typical and seems to be preferable. Men with 30 ng/ml or higher levels were less likely to have high Gleason scores or cancer found outside the prostate gland itself.
Men with dark skin and those who live in northern regions (such as Chicago, where the study was conducted) are more likely to have low levels of vitamin D. The researchers recommend vitamin D supplements to bring levels to normal.
Do Vitamin D Supplements Make a Difference?
We could find no experiments in which men with aggressive prostate cancers took vitamin D supplements. We would need such studies to see if supplements slow the progression of prostate cancer. In one study, however, men with early-stage low-risk prostate cancer under active surveillance took 4,000 IU per day for one year (Journal of Steroid Biochemistry and Molecular Biology, July, 2013). This dose brought 25-hydroxyvitamin D of the African-American men in the study to the same levels as those of the Caucasian men.
Men taking the supplement had fewer samples (cores) showing prostate cancer when their biopsies were repeated after a year (Journal of Clinical Endocrinology and Metabolism, July, 2012). This study suggests that vitamin D supplementation may have value for men with prostate cancer. However, scientists should follow up with a randomized, placebo-controlled study.
What Level of Vitamin D Is Best?
Q. I had prostate cancer several years ago. My oncologist is a big believer in vitamin D3 supplements. He measures my blood levels every six months and wants me to keep my level over 50 ng/mL.
Isn’t that excessive? I was doing some research on the Internet. There, I found recommendations that 25 hydroxyvitamin D should be between 20 and 40 ng/mL. What do you think?
A. Scientists believe that adequate vitamin D levels may have anti-cancer activity (Journal of Steroid Biochemistry and Molecular Biology, July 2023). Men who are deficient in this nutrient appear to be more vulnerable to prostate cancer progression (Journal of Nutritional Biochemistry, Jan. 2023).
Learn More About Vitamin D:
To learn more about testing, healthy levels and supplements, consult our eGuide to Vitamin D and Optimal Health. The 50 ng/mL level your oncologist recommends is not unreasonable.