Oh, I know what you are going through. I used to get cramps in both my calves at the same time, usually one would start and then the other would chime in. So, I would point my toes skyward to stretch my calves out, and my shins would cramp up...that was the worst! haha, I had no where to stretch!
Dehydration, calcium/magnesium/zinc and potatssium can all be related to it as can sitting in a closed position. Make sure you drink plenty of water, eat your green veggies and whole grains. If you can eat dairy, have some cottage cheese. Talk to your doctor about which suppliments and amounts to take and take time to stretch and walk about. Be sure not to sit in a reclining position or with crossed legs for to long.
Also, if you would like to know which foods have specific vitamins or minerals and such, check out nutritiondata.com actually, I think they are nutritiondata.self.com now. You can look up foods to see what they have, or you can look up foods by content of specific componants, like foods high in calcium, or foods low in saturated fat and so on. There is a lot to the site, but it is fantastic.
Hang in there!