Most muscle twitches are caused by the lack of calcium in the body. Due to insufficient calcium intake or malabsorption, the calcium level in human blood is reduced, and the excitability of the nerve muscles will increase, causing muscle twitching symptoms. The more serious the calcium deficiency is, the more serious the muscle twitching symptoms will be. It occurs mostly in adolescents during the growth period and in pregnant women in late pregnancy, mainly due to the increased demand for calcium. It may also be due to middle-aged and elderly patients, who have increased calcium loss or impaired absorption. Insufficient sunlight exposure can also lead to vitamin D deficiency, which affects calcium absorption. Mild calcium deficiency can be supplemented primarily through diet, with more foods high in calcium. If calcium deficiency is more severe, targeted vitamin D supplements and calcium supplements such as calcium carbonate D3 are needed, as well as more sun exposure or outdoor activities.