Recent, groundbreaking medical research has made a connection between Vitamin D deficiency and 17 types of cancers, including breast, colon, and prostate. Illnesses such as influenza, diabetes, multiple sclerosis, and coronary heart disease have also been connected to a lack of this vitamin. Until not too long ago, not getting enough Vitamin D (the sunshine vitamin) was only associated with rickets, the childhood bone disease.

Now, Soram Khalsa, M.D., sheds new light on the power of this long-forgotten vitamin. He reveals how to recognize signs of Vitamin D deficiency, which has...