“A tan may even protect the skin from the damaging effects of sunlight and so, to many, the concept of skin damage caused by sunlight seems faintly ridiculous.” -“Sun and the Skin.” It has been proven that tanning, although excessive amounts is unhealthy, helps to protect the skin from major damage. It has also has been proven that Vitamin D production increases from the sun.
Vitamin D Production
Vitamin D helps regulate levels of calcium and phosphorus in the bloodstream, which are both necessary to bone building. Vitamin D is important in keeping bones from becoming brittle. It also helps prevent rickets in children and osteomalacia in adults. Although Vitamin D can be found in food sources it is much more effective in sunlight. Not only is it more effective it is also faster because Vitamin D can be produced from only fifteen minutes in the sun but food sources only allow Vitamin D to slowly increase.
 Marks R. Sun and the Skin.