A new study suggests that vitamin D deficiency is linked to an increased risk of aggressive prostate cancer in men.

According to a study published in Clinical Cancer Research, a journal of the American Association for Cancer Research, a deficiency in vitamin D was linked to aggressive prostate cancer and metastasis of the disease in African-American and European-American men.

Study researcher Adam B. Murphy, MD, MBA, assistant professor in the department of urology of the Northwestern University Feinberg School of Medicine, and colleagues found low levels of vitamin D to be an indicator of aggressive forms of the disease in men.

“In our study, vitamin D deficiency seemed to be a predictor of aggressive forms of prostate cancer diagnosis in European-American and African-American men,” said Murphy in a statement. “Vitamin D deficiency seems to be important for general wellness and may be involved in the formation or progression of several human cancers. It would be wise to be screened for vitamin D deficiency and treated.”

Vitamin D is a group of fat-soluble secosteroids that has been known to influence the growth and evolution of prostate cells in animal models of prostate cancer. The normal range of 25-hydroxyvitamin D (25-OH D) is between 30 to 80 nanograms per milliliter (ng/ml).

The study analyzed African-American and European-American men, and found that they had 4.89 and 3.66 times a higher risk of developing aggressive prostate cancer, respectively, if their levels of 25-OH D were under 12 ng/ml when their prostate biopsy was conducted. Moreover, African-American men were 2.43 times more likely to develop prostate cancer with levels of 25-OH D under 20 ng/ml.

African-American men showed a much stronger association for the spread and aggressiveness of prostate cancer as compared to European-American men. Skin color in men may have something to do with the differences seen among both groups.