Including: Cancer, Hypertension, Heart Diseas, Autism, Obesity, Rheumatoid Arthritis, Diabetes 1 and 2, Multiple Sclerosis, Crohn's Disease, Signs of Aging, Insomnia, Hearing Loss, Osteoporosis, Macular Degeneration, Migranes, Depression, and even Alzheimer's Disease. And the list goes on.
Here's a link to an excellent article on Vitamin D3 by Dr. Mercola.