Fewer cases of melanoma were found in regular users of vitamin D supplements than in non-users, according to a new study.
People who regularly take vitamin D supplements also had a considerably lower risk of skin cancer, according to the researcher’s estimates.
The study was completed by researchers from the University of Eastern Finland and Kuopio University Hospital. Their research assessed close to 500 people with an increased risk of skin cancer.
The findings have been published in the journal Melanoma Research.
The link between Vitamin D and skin cancer
Vitamin D is vital to the normal function of the human body and may also play a role in many diseases. Previous studies on the link between vitamin D and skin cancers have focused on serum levels of calcidiol, which is a metabolite of vitamin D, and its association with skin cancers.
The results of these studies have often been inconclusive and contradictory. Levels of serum calcidiol have been associated with both a higher and lower risk of different skin cancers in previous studies.
Serum calcidiol analyses do not provide information on the metabolism of vitamin D in the human skin, which may explain the inconclusiveness of previous studies. This metabolism can express enzymes that generate biologically active vitamin D metabolites or inactivate them.
A total of 498 adult patients, deemed to have an increased risk of skin cancer, participated in the study. Experienced dermatologists at the University of Eastern Finland carefully examined patients’ background information, medical history and skin.
Additionally, dermatologists classified the patients into different skin cancer risks classes, such as low risk, moderate risk or high risk. The patients were divided into three groups: non-users, occasional users and regular users, based on their use of oral vitamin D supplements.
Serum calcidiol levels were analysed in half of the participants and were found to correspond to their use of vitamin D. supplements.
Regular uses of vitamin D supplements showed lower cancer risk
The results showed that considerably fewer cases of melanoma were present in regular users of vitamin D than in non-users. The researchers also found that the skin cancer risk classification of regular users was considerably better than non-users.
The findings suggest that even those who use vitamin D supplements occasionally may have a lower risk for melanoma. However, there was no significant association between the use of vitamin D supplements and the severity of photoaging, facial photoaging, actinic keratoses, nevus count, basal cell carcinoma and squamous cell carcinoma.
Other recent studies have also provided evidence of the benefits of vitamin D in melanoma, such as of the association of vitamin D with less aggressive melanoma.
“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,” said Ilkka Harvima, professor of dermatology and allergology at the University of Eastern Finland.
The researchers had previously reported that the melanoma mortality rate in North Savo is relatively high in relation to its incidence.
“For this reason, too, it is worth paying attention to the sufficient intake of vitamin D in the population in this region,” Harvima concluded.
