Plasma concentrations of 25-hydroxyvitamin-D3 (calcifediol) as an indicator of ultraviolet radiation.

Vitamin D3 is produced in the skin of animals and humans by the sun's ultraviolet rays (UVB region, 290-315 nm). The main metabolite 25-hydroxyvitamin-D3 has a seasonal variation, depending on the ultraviolet radiation. In the Antarctic preliminary investigations on penguins (Pygoscelis papua), female sea elephants (Mirounga leonina), and humans showed that there was an increase in plasma 25-hydroxyvitamin-D3 concentrations during UV-exposure in all three species. This metabolite can therefore be regarded as a molecular indicator of UV radiation. The possibility to use this compound in a long term monitoring program, for UV radiation, is under investigation.