Despite biologic plausibility and widespread enthusiasm, evidence that vitamin D reduces cancer incidence and related mortality is inconsistent and inconclusive.
The available research doesn’t establish a cause–effect relationship.
New studies assessing moderate-to-high-dose vitamin D supplementation for cancer prevention are in progress and should provide additional information within 5 to 6 years.
The bottom line?
Although future research may demonstrate clear benefits of vitamin D related to cancer and other nonskeletal health outcomes, and possibly support higher intake requirements, the existing evidence falls short.
John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at www.Vicus.com, a complementary and alternative medicine website.