Oz on Call

How can I tell if the sun is damaging my skin?

Jen loves sunbathing and she thinks she looks better with "a nice glow." But how much sun is too much? "Getting enough sun is actually good for you. It builds up some of the nutrients that you have to have," Dr. Oz says. "The problem is we don't know when to stop."

target=_blank> Dr. Oz explains how skin works.  

Everyone needs a little sun exposure—Dr. Oz recommends about 15 to 20 minutes per day. Without enough sunlight, the body might not build up enough vitamin D, which helps protect from cancer and possibly high cholesterol. "The sun turns cholesterol into vitamin D, so the body knows if it's not getting enough sun to elevate the cholesterol so there's at least a little bit there to get transferred to vitamin D," Dr. Oz says. Some people also suffer from Seasonal Affective Disorder (SAD), which means that they become depressed because they are not seeing any sunshine.

While some moderate exposure to the sun has benefits, Dr. Oz says sunbathing or tanning for hours is a serious health risk. Without protection, the sun's harmful ultraviolet rays can penetrate straight into your skin, causing sunburn, skin cancer and aging.

One sun worshipper gets tested for skin cancer .

"If you get too much sun, the sweat glands shrivel up—the sweat, of course, dries up. The skin itself begins to get desiccated," Dr. Oz says. "You're destroying this covering, and therefore the skin can't protect itself." The body's natural defense against too much sun is melanin, which makes skin dark, but too much exposure can cause the melanin to stain your skin, leaving age spots.