There are many reasons for low calcium twitching, as follows: a. Hypocalcemia can cause an increase in muscle nerve excitability, resulting in twitching hand and foot twitching. Short-term hypocalcemia is mainly seen in respiratory alkalosis caused by hyperventilation, making a rapid decrease in serum ionized calcium. Second, hypoparathyroidism and vitamin D deficiency, pseudohypoparathyroidism is the main cause of chronic hypocalcemia causing convulsions. Hypothyroidism, due to the lack of parathyroid hormone, causes low calcium and high phosphorus, and chronic twitching of the hands and feet. Third, if the body is not deficient in parathyroid hormone, but the body is not sensitive to parathyroid hormone, it can also cause hypocalcemic convulsions. Fourth, vitamin D deficiency causes the intestines to be unable to absorb calcium, making the appearance of hypocalcemia, is also one of the causes of low calcium convulsions. If our body vitamin D metabolism is disturbed, vitamin D can not be converted into active form, but also can not play the role of intestinal absorption of calcium, can appear hypocalcemia convulsions. Fifth, diseases of the kidneys cause abnormal loss of calcium, can also trigger hypocalcemic convulsions. Sixth, acute pancreatitis taking certain drugs, such as phenytoin sodium, rifampin, and even diarrhea and constipation, which prevent the absorption of calcium, can appear hypocalcemic convulsions.