MAGNESIUM can cause diarrhea and cramping if taken in too large a dose. Milk of magnesia is a common supplement given for loosening the bowels. 1 ounce of grape juice taken with a quarter of the lowest dose of magnesium provides for a good night's sleep while releasing the body's own natural tryptophan. Magnesium citrate is a good alkalizer & used to treat kidney stones. Some have tried magnesium oil spray to squelch leg cramps in the moment.