Crampex Tablets Crampex Tablets provide relief from night time muscle cramps in adults & the elderly. Low levels of calcium can contribute to muscle cramps, so Crampex Tablets contain calcium gluconate & cholecalciferol (vitamin D) to increase calcium levels in the blood. They also contain nicotinic acid to improve circulation. Cramps normally occur in spells lasting from a few days to a few weeks so Crampex Tablets should be taken each night for as long as you think the attacks will last.