Dr. Grant explains the various forms of UV light and how they relate to cancer risk. UVA light penetrates deeply but most sunscreens don't block it and it is what causes melanoma; this actually increases the risk for melanoma! If you shadow is shorter than you are, UVB is present and will make it possible to make vitamin D. Vitamin D deficiency is linked to three types of cancer: digestive, reproductive, and blood cancers. There are about 10,000 deaths from melanoma and 500,000 deaths from other cancers.
