Our body’s main source of vitamin D is from unprotected sun exposure to our skin.
Over-exposure to the sun’s rays — staying out in direct sunlight all day long and getting burnt — can most definitely cause skin aging and DNA damage that, yes, can even lead to skin cancer.
Many believe this is because UVB-blocking, chemical sunscreens keep skin from burning and so allow people to stay out in the sun longer, all the awhile they’re still getting exposed to those damaging UVA rays with no protection.
The darker your skin, the more exposure you’ll need — the lighter your skin, the less exposure you’ll need.