The government's dietary recommendations are 200 IUs a day up to age 50, 400 IUs to age 70, and 600 IUs over 70. But many experts believe that these recommendations are far too low to maintain healthful vitamin D levels.
Crater Lake National Park. Crater Lake National Park is a United States National Park located in southern Oregon. Established in 1902, Crater Lake National Park is the fifth-oldest national park in the U.S. and the only national park in Oregon. The park encompasses the caldera of Crater Lake, a remnant of a destroyed volcano, Mount Mazama, and the surrounding hills and forests.
Centuries of rain and snow filled the caldera creating Crater Lake. With a depth of 1932 feet (589 meters), Crater Lake is the deepest lake in the United States and the seventh deepest lake in the world. Collapse calderas form when a large magma chamber is emptied by a volcanic eruption or by subsurface magma movement. The unsupported rock that forms the roof of the magma chamber then collapses to form a large crater. Crater Lake and many other calderas are thought to have formed by this process.