Recently my daughter came home from day camp with a horrible sunburn on her back, where she and her teachers had forgotten to apply sunscreen. She is, like me, fair skinned, burns and freckles easily, and doesn't tan much at all. I have to harangue her to remember to apply sunscreen, but is there a cost? Is there toxicity, or, will sunscreen block her vitamin D production? I decided to look into this question a little more deeply. What is the best way to enjoy the summer weat