it is a naturally occuring sugar alcohol. too much and it acts as a laxitive. It can also contribute to irritable bowel syndrome and cause diarrhea, but in moderation no real risks. It is just a lower calorie sweetener.
Potassium deficiency is a factor in causing lactic acid cramps and can also exaggerate the effects of not ingesting enough sodium. Muscles and nerves are activated by electrolyte activity between interstitial fluid and inter cellular fluid.