Vitamin D deficiency is not benign. It has devastating consequences. It exists, not in the few, but in the many. In this book we will take a good hard look at the damage caused by what should be regarded as a hormonal deficiency. Over a thousand genes are regulated by vitamin D-genes that promote health and defend against disease. The risk of cancer, diabetes, autoimmune disease, cardiovascular disease, and many others including Parkinson's disease and Alzheimer's disease, is elevated when vitamin D is in short supply. Here we will explore the risks and the issues surrounding vitamin D deficiency. We will listen to what the experts have to say, as well as the advice they have to offer. Come with me and I will take you on a journey that may alter the course of your life. You will learn so much in the pages of this book.