Study links vitamin D, skin cancer

Detroit - A new study links higher levels of vitamin D within the normal range with an increased risk of nonmelanoma skin cancer, Medpage Today reports.

In a cohort study, researchers at Detroit’s Henry Ford Hospital analyzed data from 3,223 white members of a health maintenance organization (HMO) who had a high probability of developing nonmelanoma skin cancer (NMSC). The participants had sought counseling for osteoporosis or low bone density between January 1997 and December 2001, and their assessment included levels of serum 25(OH)D, a marker for vitamin D intake and storage.

Investigators found that 240 patients developed NMSC, including 49 with squamous cell carcinoma, 163 with basal cell carcinoma and 28 with both. The great majority of these cases - about 80 percent - occurred in sites frequently exposed to the sun. When patients were divided into four groups according to their 25(OH)D levels, there was a significant trend linking the higher levels and skin cancer risk.

Researchers concluded that their study adds to “the limited and conflicting epidemiological investigation regarding the relationship between vitamin D and (NMSC).” Indeed, other research suggests that vitamin D might actually reduce the risk of basal cell carcinoma.

Investigators noted that the study’s findings might be confounded by such factors as participants’ vitamin D levels over a lifetime and consumption of vitamin D supplements, which reviewers were unable to investigate. They also caution that the study was conducted at a single institution and that these particular participants - who, having sought counseling for osteoporosis risk, were a self-selected group - may not be a representative population.

The study was reported online in Archives of Dermatology.