Foot cramps can be seen in many conditions, and calcium deficiency is only one of the possible causes. Calcium ions can inhibit the excitability of the neuromuscular junction, which increases when calcium is deficient, and therefore nocturnal calf cramps and twitches can occur. In addition, patients are also prone to foot cramps after very strenuous exercise, including a lot of sports, because after sports, a large amount of lactic acid accumulates in muscles and joints all over the body, which can cause soreness and pain in the feet. Post-exercise is often accompanied by local muscle strain as well, so spasmodic pain in the feet and lower legs, or cramps in the feet and lower legs, can occur.