I have tight calves but they are flexible, too, so stretching doesn't seem to help. My cramps pre-date this diet by a few years. I've tried a lot of supplements, usually with some measure of success, but it was a lot of different supplements I was taking. Now I take a calcium/magnesium/potassium supplement and that seems to do the trick. My cramps included also tensing my jaw and grinding my teeth together, which hurt like hell. I'm glad the calcium/magnesium/potassium supplement works. The three together seems to have been the key for me. I can even take a fairly minimal dose now and get relief.
Female, 5'3", 49, Starting weight: 163lbs. Current weight: 135 (more or less).
Starting squat: 45lbs. Current squat: 160 x 2