Vitamin D supplements may be associated with lower risk of melanoma

A recent study found that people taking vitamin D supplements regularly had a considerably lower risk of developing melanoma than those who did not use the supplement.

The study, published in the journal, Melanoma Research, was conducted by scientists at the University of Eastern Finland in Kuopio, Finland. According to researchers, previous studies have focused on serum levels of calcidiol, a metabolite of vitamin D, and its association to skin cancer risk. However, many of the results came out contradictory or inconclusive, in part because scientists didn’t measure participants’ metabolism of vitamin D in the human skin.  

For this investigation, researchers sought to better understand whether vitamin D could help prevent skin cancer in those at high risk for the condition. To do this, researchers recruited 498 adult participants from the dermatological outpatient clinic of Kuopio University Hospital. All patients had an increased risk of skin cancer including basal cell carcinoma, squamous cell carcinoma, and melanoma.

The participants’ risk was classified as namely low risk, moderate risk, or high risk. The participants were also divided into three groups depending on their vitamin D usage: non-users, occasional users, and regular users. Serum calcidiol levels were analyzed in half of the patients and they were found to correspond with their self-reported levels of vitamin D intake.

Results of the investigation showed that among the vitamin D users, there were significantly fewer cases of melanoma than non-users. In addition, logistical regression analysis found that the risk of melanoma among regular users was more than halved compared to non-users.

Other findings, however, suggested no association between use of vitamin D and the severity of photoaging, facial photoaging, actinic keratosis, nevus count, basal cell carcinoma, or squamous cell carcinoma. In addition, serum levels did not seem to be related to skin changes, and researchers were unable to determine a causal relationship between vitamin D and skin cancer risk.

According to the study’s authors, these results show a clear association between regular vitamin D supplementation and risk of melanoma. However, they said more research is needed to determine the specifics of how to use vitamin D supplementation to lower the risk of melanoma.

"These earlier studies back our new findings from the North Savo region here in Finland," said study author, Ilkka Harvima, MD, PhD, a professor of Dermatology and Allergology at the University of Eastern Finland. “However, the question about the optimal dose of oral vitamin D in order to for it to have beneficial effects remains to be answered. Until we know more, national intake recommendations should be followed."