Ultraviolet (UV) light from the sun helps the body produce vitamin D. But too much UV light can damage the body's DNA, or genetic material, increasing the amounts of melanin and other chemicals produced by skin cells. Melanin tries to protect the skin from the UV light and darkens the skin, but too much of this chemical can damage the skin. On the other hand, getting an adequate amount of sunlight is important for health. Sensitivity to the sun depends on the amount of melanin in the skin. Darker-skinned people have more melanin and greater protection against the sun's harmful effects than fair-skinned people.
Sunburn
Sunburn can occur a few hours after being in the sun. Sunburn, rather than tanning, is often a signal that the person is at risk for more serious skin damage later in life. Freckles are also a result of sun damage, according to the American Academy of Dermatology. Sun protection is needed for people who get sunburn and freckles.
Aging
Overexposure to the sun can cause premature aging of the skin. It may take 20 to 30 years for sunlight damage to build up. Too much sun exposure may lead to wrinkles, redness, age spots or liver spots and rough, leathery skin. Fair-skinned people are at higher risk, but skin damage from the sun can happen to anyone.
Damage from the sun is difficult to reverse. Chemical peels, creams and laser skin resurfacing may improve appearance. Moisturizing creams help hide wrinkles.
Cancers
Too much sun also increases the risk of skin cancer, the most dangerous effect of sun exposure. These cancers include basal cell carcinoma and squamous cell carcinoma, which are easily treated if detected early, and malignant melanoma, which is often fatal. Long-term sun exposure often results in precancerous growths. Among them are actinic keratoses, which often appear as flaky, scaly patches or dark-brown, hardened spots. They are easily noticed and can be removed by a dermatologist with a freezing technique using liquid nitrogen.
Vitamin D Benefits
The sun offers great benefits, including the production of vitamin D in the body. Research reported in the June 9, 2008, issue of the "Archives of Internal Medicine" found that people with low levels of vitamin D had twice the risk of dying from heart disease than people with high levels of the vitamin. Outdoor activity is essential for sufficient vitamin D levels. Vitamin D also may protect people from cancers of the breast, prostate and colon, and osteoporosis. The sun is a valuable ally in helping people with depression.
