VITAMIN D supplements have been linked to a lower number of cases of melanoma, according to a new study conducted in Finland. People who took vitamin D supplements had a lower risk of skin cancer. Previous studies on the link between vitamin D and skin cancers had focused on serum levels of calcidiol and its association with skin cancers; however, results of these studies have been contradictory, showing both a higher and lower risk of different skin cancers associated to serum calcidiol levels.
For this study, 598 adult participants with an increased risk of skin cancer, including melanoma, squamous cell carcinoma, and basal cell carcinoma, were recruited. Their background information and medical history was analysed and skin was examined. The researchers then classified them into three skin cancer risk classes: low, moderate, and high risk. The participants were divided into three groups (non-users, occasional users, and regular users), based on their use of vitamin D supplements. The team analysed serum calcidiol levels in half of the participants, and found that these corresponded to the reported use of supplements.
They noted a considerably lower number of cases of melanoma among regular users compared to non-users, and a considerably better skin cancer risk classification in regular users compared to non-users. Through logistic regression analysis, the team showed that the risk of melanoma in regular users was more than halved, compared to non-users. Furthermore, even occasional users may have a lower risk for melanoma. The research did not show a statistically significant link between use of vitamin D and severity of photoaging, actinic keratoses, basal cell carcinoma, squamous cell carcinoma, facial photoaging, and nevus count; and there was no significant association between serum calcidiol levels and skin changes.
Due to the cross-sectional design of the study, the researchers could not demonstrate a causal relationship. However, other recent studies have also shown an association of vitamin D with less aggressive melanoma, and Ikka Harvima, University of Eastern Finland stated: “These earlier studies back our new findings from the North Savo region here in 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.“