People who wear sunscreen probably lower their risk of skin cancer and wrinkles. People who wear sunscreen remain at risk for skin cancer and wrinkles.

All of the above statements are true, and some have received wide publicity. The mixed message worries skin doctors.

"Unfortunately, there's a lot of confusion out there right now," says James Spencer, a dermatologist in St. Petersburg, Fla. The confusion stems from:

• A flurry of new studies suggesting — though not proving — that vitamin D, which is readily available through modest sun exposure, can reduce the risk of diabetes and of breast, colon, ovarian and prostate cancers.

• A class-action lawsuit filed against sunscreen makers that says sunscreens don't work as well as labeling and advertising suggest.

Consumers who don't read past headlines might be tempted to either head to the beach, slather on some baby oil and let the baking begin or to head to the nearest cave and stay there until fall, because apparently nothing can protect them from the ravages of the sun.

Neither would be a healthy choice.

"A little bit of sun may be OK," says Stephen Stone, a dermatologist in Springfield, Ill., and president of the American Academy of Dermatology. It's possible, he says, that vitamin D has great benefits. But extensive, unprotected sun exposure remains a major cause of skin cancer and most of the wrinkling and spotting that come with age.

(You can get an idea what the sun does to your skin by comparing the back of your hands to the insides of your upper arms, Spencer says.)

"By the time they are 50 years old, everyone wishes they had spent less time in the sun," says dermatologist Barbara Gilchrest of Boston University.

Adequate vitamin D (which might be as much as 1,000 international units a day) can be obtained more safely from foods, such as fortified milk and salmon, and supplements, dermatologists say.

The chief advocate for sun exposure is Boston University's Michael Holick, who suggests people briefly expose their faces and arms to the sun a few times a week. His recommendations vary by skin type, latitude, time of day and season.

He prescribes the least exposure (two to eight minutes at midday, in New York, in summer) for the palest people and the most (25 to 35 minutes in the same setting) for those with the darkest skin, who are most likely to be low on D.

He says he is frequently misunderstood.

"I don't promote nor do I advocate tanning," he says.

Dermatologists say Holick's advice is easily misused — by tanning fans and those who profit from them, including tanning salons — to justify unhealthful habits.

"People are already not wearing their sunscreen ... going to the beach for hours and hours without protection," Spencer says. One large study of teens found only one-third used sunscreen at the beach, he says.

Most people, he says, easily get a few minutes of unprotected sun exposure: "We are not a nation of vampires who only come out at night."

As for the sunscreen lawsuit, manufacturers dispute the allegations and stand by their products and labels.

Dermatologists say sunscreens are not perfect: They let through some potentially damaging rays, are not waterproof and don't last all day.

But sunscreens prevent skin cancers in studies of animals and prevent burns, which are strongly linked to melanoma cancers, in humans, Gilchrest says.

Says Spencer: "They're inconvenient and messy, but they are the best thing we've got."

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