Increased Vitamin D levels were associated with nonmelanoma skin cancer

Eide MJ. Arch Dermatol. 2011;doi:10.1001/archdermatol.2011.231.

Issue: September 10, 2011

Higher levels of serum 25-hydroxyvitamin D were associated with an increased risk for nonmelanoma skin cancer, a finding that may be explained by the positive relationship found between UV exposure and both vitamin D synthesis and nonmelanoma skin cancer, according to recently published data.

Researchers conducted a cohort study of 3,223 white patients from a health maintenance organization who sought advice related to osteoporosis or low bone density during 1997 to 2001. They defined sufficient vitamin D levels as a baseline serum 25-hydroxyvitamin D level =30 ng/mL, and defined deficient levels as <15 ng/mL.

More patients had a vitamin D deficiency (n=2,257) than were vitamin D sufficient (n=966). Two hundred and forty patients had nonmelanoma skin cancer, including 49 with squamous cell carcinoma, 163 with basal cell carcinoma and 28 with both.

Vitamin D levels greater than the deficient level of 15 ng/mL were associated with nonmelanoma skin cancer (OR=1.7); this finding existed after adjusting for demographics and other risk factors (adjusted OR=1.8). The researchers reported that this finding was not significant on less UV-exposed anatomical locations (adjusted OR=2.2), with a lower risk estimate for basal cell carcinoma (OR=1.7) compared with squamous cell carcinoma (adjusted OR=3.2).

“The direct relationship of UV exposure with both vitamin D and nonmelanoma skin cancer makes it a likely profound confounder in this and other studies,” the researchers wrote. “In the future, analysis of a prospective cohort that is representative of the general population, ideally with available UV-exposure estimates, risk factor and dietary and supplemental vitamin D information, is essential to further elucidate the highly complex relationship between vitamin D and nonmelanoma skin cancer.”

Follow HemOncToday.com on Twitter.