What is the most abundant mineral in the human body?

Calcium is the most abundant mineral in the human body. Most of it is stored in bones and teeth, where calcium compounds provide hardness and structural support, but calcium ions also perform essential jobs throughout the body.

An average adult contains roughly 1 kilogram of calcium, with about 99% located in the skeleton. The remaining calcium is found in blood and soft tissues, where it helps muscles contract, nerves transmit signals, blood clot, and many enzymes function. Calcium levels must remain within a narrow range because both deficiency and excess can disrupt normal physiology.

Bone is not an inert warehouse. It is continually remodeled, with calcium moving between bone and the bloodstream. Parathyroid hormone helps raise blood calcium when levels fall, while vitamin D increases intestinal calcium absorption. The thyroid hormone calcitonin can also influence calcium handling, although the parathyroid glands are the principal regulators.

Calcium is different from the most abundant element in the body by mass: oxygen holds that distinction, largely because the body contains so much water. The question asks for the most abundant mineral, making calcium the standard answer.