I can't say anything for tanning beds specifically, since I was diagnosed at a young age I've never been in a tanning bed. But, being out in the sun for too long, as Lynnwood said, tends to send me into a flare. This past summer however, I would put sunscreen on, and then go outside for maybe 20 minutes a day. It wasn't enough to get any color but I noticed a MAJOR improvement in my skin. It was less flaky and itchy, and my acne cleared up quite a bit. So it will obviously affect each person differently, but in my experience a little sun exposure goes a looong way.