The Vitamin D and Skin Cancer Quandry

Nonmelanoma skin cancer risks may increase with serum vitamin D levels

(RxWiki News) After a host of scientific studies linking low levels of vitamin D and various diseases, here comes a study that suggests just the opposite. But maybe not. Don't you just love conflicting health news?

New research shows that there seems to be a link between adequate vitamin D levels and increased risks of skin cancer, specifically nonmelanoma skin cancer (NMSC). But since the sun has an impact on these levels, the link is hard to nail down for sure.

"Ask your doctor if you should take vitamin D supplements."

Ultraviolet (UV) radiation from the sun is known to cause skin cancer. Sunlight - UV-B - also produces vitamin D in the body.

The exact nature of the relationship between vitamin D levels and skin cancer has been inconsistent. Some studies have indicated that serum (circulating through the blood) vitamin D levels reduce the risks of basal cell carcinoma (BCC), the most common form of NMSC. There are two subtypes of NMSC - BCC and squamous cell carcinoma (SCC). 

To examine the association between vitamin D and BCC and SCC, researchers worked with a group of 3,223 Caucasian members of a health maintenance organization (HMO). Patients, all of who were at high risk of developing skin cancer, had been counseled for osteoporosis or low bone density between January 1997 and December 2001.

Melody J. Eide, M.D., M.P.H., and colleagues from Henry Ford Hospital in Detroit followed up with these patients for almost 10 years. Assessments during this time included measuring blood vitamin D levels.

Here's what the study revealed:

  • 2,257 people had low levels of vitamin D
  • 240 patients developed either SCC, BCC or both
  • People who were not deficient in vitamin D had an increased risk of developing NMSC
  • This association wasn't statistically significant for tumors that formed on parts of the body that aren't normally exposed to the sun

So what's the meaning of all this? No one knows. The authors write in the report published by Archives of Dermatology  that the findings add "to the limited and conflicting epidemiological investigation regarding the relationship between vitamin D and NMSC."

And what does that mean? You guessed it. More study is needed.

Non-melonoma skin cancer is the most common malignancy in the United States.

Review Date: 
August 15, 2011