I've taken magnesium daily for years. When I log my food on Cronometer magnesium usually comes up somewhat deficient. Beause of my sensitive gut I take magnesium glycinate, a form of magnesium that does not act as a laxative. I've had problems with other, less expensive (of course) forms of magnesium. I've found that by supplementing with both magnesium and potassium I have virtually eliminated muscle cramps.

Potassium supplement by law contain very small amounts of potassium so I follow Dr Eades' advice:

"Potassium is linked to sodium. If you lose a lot of sodium through the diuretic effect of the low-carb diet, you’ll ultimately lose a lot of potassium as well. Keeping your sodium intake up as mentioned above will help preserve your potassium as well. And keeping your potassium levels up helps to ensure that you don’t lose a lot of lean muscle mass during your weight loss. Plus, just as with sodium, adequate potassium prevents cramping and fatigue.

You can replace your potassium by taking potassium supplements. In our clinical practice, we gave all patients starting the low-carb diet a prescription for potassium. You can get the same dosage by taking four to five of the over-the-counter 99 mg potassium supplements you can purchase at any health food or natural grocery store.

There are a couple of prescription medicines that you’ve got to be aware of if you markedly increase your potassium intake, so if you’re on blood pressure medicines, ask your doctor if it’s okay for you to take potassium."

I've also been doing this for years, although fewer year than I have been taking magnesium. Adding it to the magnesium stopped any cramping problem I was having.

Jean