Cramps are usually caused by insufficient magnesium, whilke muscle fatigue and a general feeling of weakness can be caused by lack of potassium.

Magnesium is best absorbed when combined with calcium, in a 2cal:1mag formulation. You should be taking 1000:500mg daily, in divided doses.

Potassium can be replaced either as a potassium salt such as No Salt or as tablets. You should be taking 400mg daily, again in divided doses. Actually potassium should be taken with food, otherwise it can irritate the stomach. And if you take drugs for fluid or high blood pressure, check first with your pharmacist before taking potassium supps.

Cheers.

Rosebud