The Truth About Vitamin D

The Sunscreen Debate

Experts are firmly divided into two camps when it comes to the matter of sunlight and vitamin D. The main reason that most of us are short on D is because we simply aren't outside very often. And when we are, we may wear sunscreen or protective clothing to guard against skin cancer. Plus, the angle of the sun from November through March in northern states prevents us from getting the rays we need. Regardless of where you live, early-morning or late-afternoon sun doesn't help you make D. If you have dark skin, melanin makes it even harder to produce enough.

The obvious solution seems to be to spend time in the midday sun without protection. But this advice, advocated by some vitamin-D experts, has become a lightning rod for controversy. In one corner are people like Dr. Holick. You don't need lots of sun to boost D levels, he says; you can benefit from five to 30 minutes of unprotected exposure two to three times per week, depending on your skin color. If you get plenty of sun during the warmer months, you can make enough D to carry you through the winter, he adds. "I don't put sunscreen on my kids for the first ten minutes they're in the sun," says D researcher Michal L. Melamed, M.D., assistant professor in the departments of medicine and epidemiology at Albert Einstein College of Medicine, in New York City.

In the other corner are those who say that it's best to avoid sun exposure. "Kids should wear sunscreen all the time, and babies under 6 months should stay out of the sun," insists Dr. Greer. Pediatrician Maribeth Bambino Chitkara, M.D., a spokesperson for the Skin Cancer Foundation, agrees. Since her 29-year-old sister died of melanoma, she believes that sun protection can't start too early. "UV light is carcinogenic," she says. "We can't separate the potential benefits of UV-light exposure from the inherent harm associated with that exposure."

Adults also need to take precautions, says New York City dermatologist Doris Day, M.D., another spokesperson for the Skin Cancer Foundation. "Most people get more sun than they realize even if they wear sunscreen. Why take a risk from sun exposure when a supplement will provide the same benefits?"