Just a reminder: Vitamins aren’t inert. They actually do things in your body and we don’t totally understand yet what all they do, how they do it, and how much extra vitamin supplementation is too much. Meanwhile, the vitamin and supplement industry remains largely unregulated. Most doctors probably wouldn’t tell you to stop taking vitamins, but the concerns voiced by Dr. Paul Offit in a story at CNN aren’t ridiculous and should help convince you to make sure that you’re talking with your doctor about the supplements and vitamins you take, and to be leery of megadosing on any vitamin.