Somersaulting down the sidewalk isn't the only thing that's bad for your skeleton. So is taking too much vitamin A.

Your body definitely needs some vitamin A, but more than 2,500 international units (IU) a day could hurt new bone formation.

Know Your Limits
You can't OD on food sources of vitamin A -- carrots, red peppers, sweet potatoes, and the like. (Find other vitamin-A-rich foods with this online tool). Just make sure your vitamins and supplements don't put you over the 2,500 IU limit -- and choose supplements that contain the beta carotene form of vitamin A. Other things that are bad for your bones: cigarettes and excessive alcohol.