evidence: Sunscreen is just one of the defenses against the harmful effect of UV radiation. Strategies such as seeking shade and dressing children in sun-protective clothing are just as important. A bad sunburn in childhood or adolescence doubles the risk of melanoma later in life, according to the Skin Cancer Foundation. [...] Sun Exposure & Vitamin D Some sunlight is good for you and is needed for bone health. It has been suggested by some vitamin D researchers that approximately 5 to 30 minutes of sun exposure at least twice a week to the face, arms, legs, or back without sunscreen usually lead to sufficient vitamin D. Individuals with limited sun exposure need to include good sources of vitamin D in their diet or take a supplement to achieve recommended levels of intake.