What Your Sunscreen Should—and Shouldn’t—Have

First and foremost, spring and summer mean sun. We all know we need some of it (sunshine enables our body to absorb vitamin D, which is essential for bone density and a strong immune system), but there’s also the sun’s not-so-healthy aspect: skin cancer. Since 1975, rates of melanoma—the deadliest kind of skin cancer—have tripled, reaching nearly one-quarter of the population, according to the National Cancer Institute (NCI). …