Nelie, potassium is something I have recently learned about, because a serious lack of it due to strenuous, prolonged exercise was a contributing factor to my husband's cardiac arrest (he's fine now.) So, with no further ado:

The best dietary sources of potassium are fresh unprocessed foods, including meats, fish, vegetables (especially potatoes), fruits (especially avocados, dried apricots, and bananas), citrus juices (such as orange juice), dairy products, and whole grains. Most potassium needs can be met by eating a varied diet with adequate intake of milk, meats, cereals, vegetables, and fruits.

Dried dates are also very high in potassium, but are most commonly only available around the holiday season.

Finally, I can bring on dandy cramps by pointing my toes. If I stretch by pointing my heels and pointing my toes toward my body (when lying down), no cramps.