From the Madison Health Department Safety Committee

The sun sends us heat and light and is beneficial to our health. Ninety percent of our Vitamin D comes from sunlight hitting our skin but too much sun can cause skin cancer. It is important to balance the benefits and risks of exposure to sunshine and use sunscreen correctly.

The Connecticut Department of Public Health has provided a FACT SHEET Playing it Safe in the Sun (PDF) with advice for getting the benefits while avoiding the harm from sunlight.