The classic role of vitamin D has involved its function in calcium metabolism. However, a much broader perspective of the importance of vitamin D is now emerging. Therefore, a new approach is needed based on a combination of molecular biological, physiological, and clinical/epidemiological studies. The remarkable range of the effects of vitamin D relates to our new understanding of both the role of the vitamin D receptor and analyses of what might be considered an optimum vitamin D status in populations exposed to very different diets and levels of sun exposure. Assessing the breadth of the current approaches was the basis of the 22(nd) Marabou Symposium that took place in Stockholm in June 2007. The complete proceedings will be presented in this journal as a supplement to an upcoming issue.