Calcium Unit Converter

Calcium is the most abundant mineral in your body, essential for building and maintaining strong bones and teeth. A calcium blood test measures the total amount of calcium circulating in your bloodstream.

About 99% of your body's calcium is stored in bones and teeth. Only about 1% circulates in the blood, where it performs critical functions for nerves, muscles, and the heart.

In the blood, about 50% of calcium is free (ionized) and biologically active, about 40% is bound to proteins (mainly albumin), and about 10% is bound to other molecules. A total calcium test measures all forms, while an ionized calcium test measures only the active portion.

Calcium is obtained from dietary sources such as dairy products, leafy green vegetables, fortified foods, and supplements. Blood calcium levels are tightly regulated by parathyroid hormone (PTH), vitamin D, and calcitonin, with bones acting as the main storage reservoir.