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

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 degrees N) in late winter, approximately 20% more UV is required to produce 215 J m(-2) of vitamin D weighted UV than erythemal UV.