Book introduction

This chapter is an introduction to the current edition of this book. The two founding editors, David Feldman and John Wesley Pike, have selected major themes in the vitamin D field to highlight areas of progress in vitamin D research. Some of the areas selected have been studied over many years and others are areas of new progress. The vitamin D subjects include: mechanism of action, hormonal and enzymatic regulation of vitamin D homeostasis, vitamin D receptor (VDR) mutations causing childhood rickets, vitamin D clinical assays, extra-skeletal actions, population studies and clinical trials of vitamin D deficiency and supplementation. The extra-skeletal disease covered in most detail is colorectal cancer (CRC) with emerging evidence linking vitamin D deficiency to poorer prognosis and decreased survival. All subjects in this chapter are covered in much greater depth in the cited chapters of the book.