Vitamin D and its revelance to cancer.

It has become apparent during the last few years that 1,25-dihydroxy-vitamin D, the steroid hormone that is formed from the biotransformation of vitamin D in the body, plays a much wider role in biology than it was thought until recently. Beyond its classical role in mineral and skeletal homeostasis, 1,25-dihydroxy-Vitamin D is involved in the regulation of the growth, differentiation and function of a wide range of normal as well as malignant tissues. This article provides an update of the metabolism, the mechanism of action and the role of the vitamin D endocrine system in normal biology. In addition, it reviews recent evidence for the involvement of 1,25-dihydroxy vitamin D in cancer and other malignancies and addresses the basic and clinical implications of this evidence.