Mar 23, 2015 05:32 PM EDT By Staff Reporter, UniversityHerald Reporter

New research suggests that vitamin D supplements could slow or even reverse the progression of less aggressive, or low-grade, prostate tumors without the need for surgery or radiation.

Researchers found that many of the men who received vitamin D showed improvements in their prostate tumors, whereas the tumors in the placebo group either stayed the same or got worse. Also, vitamin D caused dramatic changes in the expression levels of many cell lipids and proteins, particularly those involved in inflammation.

"Cancer is associated with inflammation, especially in the prostate gland," researcher Bruce Hollis, who is at the Medical University of South Carolina, said in a statement. "Vitamin D is really fighting this inflammation within the gland."

For the study, researchers assigned 37 men undergoing elective prostatectomies either to a group that received 4,000 U of vitamin D per day, or to a placebo group that didn't receive vitamin D. The men's prostate glands were removed and examined 60 days later.

The new research suggests that vitamin D supplementation may improve low-grade prostate cancers by reducing inflammation, perhaps lessening the need for eventual surgery or radiation treatment.

"We don't know yet whether vitamin D treats or prevents prostate cancer," says Hollis. "At the minimum, what it may do is keep lower-grade prostate cancers from going ballistic."

Hollis notes that the dosage of vitamin D administered in the study -- 4,000 U -- is well below the 10,000-20,000 U that the human body can make from daily sun exposure.

 "We're treating these guys with normal body levels of vitamin D," he said. "We haven't even moved into the pharmacological levels yet."

The findings will be discussed at the 249^th National Meeting & Exposition of the American Chemical Society.

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