Cramps that remain after calcium supplementation may be caused by a short period of supplementation in which blood calcium levels have not recovered, or by the simultaneous presence of conditions such as excessive fatigue. For those who clearly have low blood calcium, medications such as calcium gluconate, calcium carbonate, calcium lactate, and calcium chloride can be used. If the duration of medication is too short, muscle cramping symptoms may persist due to unrecovered blood calcium levels. Calcium supplementation is recommended along with medications such as vitamin D to promote absorption, and it is also recommended that organic calcium such as calcium gluconate be chosen whenever possible to minimize adverse effects. In addition, if there are factors such as muscle overexertion and cold stimulation at the same time as calcium supplementation, it may also lead to reflexive muscle cramps. If the cramping phenomenon is manifested as limb tonus with tremor or flailing, it is necessary to be alert to the possibility of epilepsy, and prompt hospitalization is recommended. The above calcium supplements should be used under the supervision of a clinician.