Vitamin D and melanoma.

Recreational sun exposure and sunburn are causal for melanoma but the risk is strongly genetically determined. Health promotion advice about sun protection should be aimed at susceptible individuals (pale skin, freckles, large numbers of melanocytic nevi and a family history). We discuss here the evidence that sun-sensitive people have lower vitamin D levels and that, in practice, it is very difficult for such individuals to achieve sufficient levels without supplementation in the UK at least. We conclude that melanoma susceptible sun-avoidant individuals should be advised to avoid insufficiency by supplementation. Vitamin D is anti-proliferative in vitro for some melanoma cell lines. In a large melanoma cohort we have observed that lower serum 25-hydroxyvitamin D2/D3 levels at diagnosis were associated with thicker tumors and poorer prognosis (study as yet not validated). In the UK, melanoma patients commonly have sub-optimal 25-hydroxyvitamin D2/D3 levels at and post diagnosis; we discuss approaches to management of such patients based on some new data from our group.