Comparison of human facial UV exposure at high and low latitudes and the potential impact on dermal vitamin D production

Abstract
The results presented in this paper allow for the estimation of the monthly UV exposure of the human facial region at various locations across the earth. The technique allows a graphical representation of the UV exposures over the face. The erythemal UV exposures as well as the vitamin D exposures to the human facial region have been investigated. The results gained in this paper, for a clear sky and constant ozone indicate that the sun's capability to promote the development of vitamin D in the human body does not follow the erythemal UV irradiances, in particular at high latitudes. For Amsterdam (52°N) in late winter, approximately 20% more UV is required to produce 215 J m−2 of vitamin D weighted UV than erythemal UV.