Magnesium

Magnesium
In addition to its role in bone health, magnesium plays an important role in stabilizing adenosine triphosphate (ATP), the energy source for muscle contraction, and also serves as an electrolyte in body fluids. Muscle weakness, muscle twitching, and muscle cramps are common symptoms of magnesium deficiency.
Limited data have suggested that magnesium status is indirectly related to the incidence of muscle cramps. In these studies of endurance athletes, the athletes who developed muscle cramps were found to have serum magnesium concentrations that were different from their competitors who did not cramp. The research, however, presents a confusing story because serum magnesium was significantly lower in cyclists who cramped during a 100-mile (160 km) bike ride and significantly higher in runners who cramped during an ultradistance race. In both studies, serum magnesium remained within the normal range but was low-normal in the cyclists who cramped and high-normal in the runners. Interestingly, studies in pregnant women have found that supplementation with magnesium (taken as magnesium lactate or magnesium citrate in doses of 5 millimoles in the morning and 10 millimoles in the evening ) show promise for treating pregnancy-associated leg cramps. Research, however, has not addressed whether dietary or supplemental magnesium can prevent or reduce muscle cramps in athletes.
Vegetarian athletes are not likely to experience muscle cramping as a result of low magnesium intake because the typical vegetarian diet is abundant in magnesium. Low magnesium intake, however, is possible for people restricting calories or eating a diet high in processed foods. Low magnesium intake should be ruled out in cramp-prone athletes.