Calculations of the Human Vitamin D Exposure from UV Spectral Measurements at Three European Stations.

Since the realization that the ozone protective layer was at risk from the build-up of anthropogenic trace gases in the atmosphere, there has been an increased interest in understanding the trends and variability of the solar UV radiation received at the surface of the earth But during the last few decades an unfolding controversy has risen It was found out that the exposure to the solar UVB radiation is responsible for the cutaneous production of Vitamin D, a vitamin which is essential for the bone metabolism and for the calcium and phosphorus homeostasis For this research study, we have processed quality-checked specual UV Irradiance measurements from three European stations (Jokiomen, Finland, Bilthoven, The Netherlands, and Thessaloniki, Greece) and the vitamin D effective doses (VDED) are calculated. As expected, the maximum VDED are observed during the second half of June, revealing the dominant effect of low solar zenith angles and cloudiness. Also the average VDED at local noon reveal that the cutaneous production of the Vitamin D can be feasible throughout the year in Bilthoven and Thessaloniki. Even for an exposure of one hour around local noon the proposed vitamin D standard dose (SDD)cannot be attained for all skin types under physiological atmospheric conditions at Jokioinen and Bilthoven.