This usually happens to everyone from time to time in their lives. It doesn't necessarily mean you're missing anything in your diet.
That's right..a stray cramp here and there seems human. But if it's a constant problem then I can give you my personal experiences..
Potassium suppliments help my foot and toe cramps fantastically. I take one "Sundown 595 MG" tablet of potassium Gluconate which provides 99 MG of elemental potassium per day (that's only 3% of the daily recommended value so it's certainly not too much) . I used to suffer terrible foot and toe cramps and taking this one tablet every day seems to really help. BUT Do not take potassium suppliments if you are pregnant or nurseing.
Calcium helps my mothers leg cramps. I didn't find it helped mine any. I take calcium for my bones anyway. However in my personal (unscientific) opinion My worst calf cramps have always been when I was working a desk job and walking very little. Walking more helps me have less calf & leg cramps.
You have to be careful about the amount of magnesium "suppliments" you take.. too much can be very much a problem. They say there is no overdose problem if you eat foods high in Magnesium but you can overdose by taking too many magnesium suppliments. My multivitamin provides 47% of the recommended daily dose and I drink Cocoa or eat chocolate, bananas, green leafy veg's or peanut butter to get the rest. I personally find Cocoa or something made of Cocoa really helps keep me "regular" so I'm quite found of the Mag in natural foods but I do not take extra "suppliments" of it.
I would suggest taking a calcium supplement that has magnesium and vitamin D. When you take the calcium wiht these two others it is usually in the correct ratio needed by the body. The vitamin D and the magnesium are needed for the proper absorption of the calcium.
I disagree with everyone gets these cramps so it isn't a big deal. It is not NORMAL to have cramps, it is not HEALTHY to have cramps, it is your body trying to tell you something. If more people listened to thier bodies instead of just shrugging off symptoms there would be many more healthy people in this world.
I had the same problem and went to the doctor for it, and he said take your choice eat banana or take a pottasium supplement. I went with the supplement, bananas are fattening. Huge difference since i started the supplement, I don't go a day without them.
You may want to consider a banana, 538.56 mg (27% RDA) potassium and , 39.44 (14%) mgmagnesium. Quite the ideal food, if you ask me . Also, ensure you're getting enough hydration. If you don't drink a lot of fluid during the day, consider adding a glass or 2 of water.
Get your thyroid checked out. I started with some calf muscle pain/spasms and increased my potassium and magnesium. No change. I increased my C, no change. My neighbor who has hypo-thyroidism(too slow) told me to get some labs for my thyroid and I did. I was diagnosed with Hashimotos Hypothyroidism, a rather comon form of it. There is no cure but you just take one pill everyday forever, get your levels checked at least once a year and that's it.
I actually lost about 20 lbs. because once my metabolism was back to normal, I was able to burn my calories normally and yes the calf pain went away...ask for a thyroid panel(TSH, FreeT4, T3, and most important, TPO), that last one the docs have a tendency not to do but it is very necessary...Good luck!