This invention is about the Use Of 1,25-dihydroxyvitamin D3 for the Treatment of Alzheimer's Disease, Dementias and Neurodegenerative Diseases in Humans.1,25-dihydroxyvitamin D3 is not a Vitamin but actually is a hormone made by the actions of sunlight and the skin and then made into the active form by the kidney.This hormone produces Cell Specific Carbonic Anhydrase Enzyme 2 which produces hydrog