In a perfect printing world,minimizing the amount of calcium pulled from the paper would be a pretty lofty goal. There are commercially available products that "claim" to do this but IMO don't work worth a damn. There are also products available that will keep the calcium in suspension within your fountain solution, helping to avoid build up on the plates or rollers. Lastly, there are fountain solution filtration systems that will filter out calcium along with other nasty stuff.
My best recommendation would be to use a 3 fold approach. 1. keep fountain solution as clean as possible with a good filtration system, and fountain additives that help keep the calcium in suspension as opposed to settling in rollers or on plate. 2. Make regular calcium rinses a "must do" part of your press maintenance schedule. 3. try to find grades of paper that don't get get their opacity, and whiteness from additives high in calcium carbonate. My guess is that you could achieve items 1 and 2 with a strong commitment to money well spent, and press maintenance. Item 3 will be harder because its really hard to resist the savings offered by a lower quality sheet that seems to use the whiteners I mentioned above.
