High-dose vitamin D supplementation does not improve outcome in a cutaneous melanoma population: results of a randomized double-blind placebo-controlled study (ViDMe trial)

Cutaneous melanoma (CM) is the most lethal form of skin cancer. Previous studies have shown that low vitamin D (VD) levels in the blood at the time of CM diagnosis are associated with thicker tumours, and a worse outcome.

The aim of this study was to examine whether monthly high-dose VD supplementation after diagnosis and surgical treatment of a primary melanoma could improve outcomes.

We carried out a clinical trial that included 436 patients with CM who were randomly allocated into two groups. One group of 218 patients received a placebo (an inactive treatment) and another group of 218 patients received a monthly oral oil solution containing VD (known as the treatment group). We looked at relapse-free survival, levels of melanoma-related mortality, overall survival, and the evolution of VD levels over time, and compared the results for both groups. We found that monthly high-dose VD supplementation was safe, but did not protect against recurrence of CM or risk of death.

Therefore, based on our study findings, we do not recommend high-dose VD supplementation for people with CM to improve melanoma outcomes.