You may want to think about sodium
I know, I know... sodium is the enemy, or so we've been told for a couple of decades, but it is also an essential mineral, and most of us need about 2 grams (2000 milligrams), more if you are a runner or other endurance athelete.
One of the reasons why folks don't mention sodium is that there is tons of it in processed food. If you eat a lot of fast food or canned food you are getting plenty of sodium. But if you are following a more clean, self-prepared diet as many of us here are, you may not be getting enough.
Like you, I was having serious calf cramps when running, or foot cramps during yoga. On a run they often start with my feet, work their way up to my calves and at the extreme end into my knees and thighs. During one race they got so bad my legs totally collapsed out from under me (its kind of a funny story - but a little too long for this post). After consulting with an MD and a nutritionist I looked carefully at what I was eating and found that I was pretty deficient in sodium (potasium too, but it was mostly the sodium that was responsible for the cramps). I don't eat much processed food, I rarely salt my food, but the most telling was that when the cramps begin, all it takes is one of the little salt packets you get with take-out food to make them go away.
Those packets are about 750 mg (0.75 g) and pretty quickly absorbed through your mouth into your blood stream.
BTW sports drinks and gels really do not have enough "electrolytes" (potassium and sodium) to be of much help - check it out for yourself, and contrary to conventional wisdom, there are more potassium rich foods that bananas (although bananas are a great food).
FitDay can help with the sodium calcs, but not the potassium - there isn't anywhere to input the numbers if you creat a lot of your own foods - so may need to do the calculations yourself.
Cramps can be really debilitating. After the race when I collapsed (which I did finish BTW) it took 2 weeks for my legs to recover, the muscles were so damaged. So prevention is definitely important. I still get cramps from time to time, but I almost always take those little salt packets along for my longer runs.
Good luck WeightlossBoo, but don't let the cramps go untreated. Sodium may not be the answer for you, but definitely figure out what the answer is. Cramps are your body telling you something is out of wack!