Pratik,
I hope that you feel better soon. I have been replenishing little A with coconut water (with minerals), cal/mag, vit B since yesterday and he seems a lot better.
During our trip he decided it was a great idea to sprint everywhere, he was running very fast the entire time and the temperature 108 F some days. I think he must have been dehydrated, because he is usually not affected by physical activity, he constantly plays ice hockey, soccer and is in track and field.
Other than dehydration, there are many reasons for cramping - ranging from minor imbalances and deficiencies to more serious such as kidney, liver or problems with blood sugar. It is a good idea to see a doctor to rule out anything serious - even though the minor problems are more likely.
I am curious to know if you are on exjade, and if there is a link between exjade and dehydration and perhaps mineral deficiencies.