It is surprising how little we really know about diet and the proper balance. Plus, every person is slightly different, and some may be very different from average. It seems though that the more science learns at this point, the harder it is to know exactly what to do. For instance, calcium is supposed to strengthen bones, so as you grow older you should take calcium. However, there is now evidence that too much calcium is associated with higher risk of cardiovascular disease. So how much is just right and how much is too little or too much?