Some folks tan, simply because its part of their culture.
Me,.. I grew up in Hawai'i, tanning is almost second nature, so I'm not really my true self if I don't catch a few rays from time to time.
In my youth, going to the beach for swimming, fishing, sailing, paragliding, hang gliding, surfing and harvesting fresh seafood from natures bounty (diving for oyster, clams, spear fishing, etc.). My dad particularly liked fishing deep water fishing on the shoreline (along craggy cliffs).
In a sense, you're not a "Kama'aina" (a local Hawai'ian resident) until you've cultivated a little bit of a tan.
True for some people that they endeavour to be as white as possible, because some folks are extremely susceptible to getting skin cancer.
However, also true, that some folks are "resistant" to getting skin cancer - simply because of the pigmentation of their own skin.
If you have the genes and your body normally produces the enzyme for your natural colouration. Getting your daily dosage for Vitamin D from the sun is essential to your good health.
Its not for everyone after all, so when in doubt consult your regular doctor and a professional Dermatologist (not some bimbo at the cosmetics counter in a department store).
o.0