Changes in serum 25-hydroxyvitamin D and cholecalciferol after one whole-body exposure in a commercial tanning bed: a randomized study.

We wanted to evaluate the cutaneous synthesis of 25OHD and cholecalciferol after one whole-body exposure to ultraviolet radiation type B (UVB) in a randomized setup. Healthy volunteers were randomized to one whole-body exposure in a commercial tanning bed with UVB emission (UVB/UVA ratio 1.8-2.