Why does citrate cause hypocalcemia?

Citrate can cause hypocalcemia because it binds to calcium ions in the bloodstream, forming a complex that reduces the amount of free, ionized calcium available for physiological functions. This effect is particularly notable during blood transfusions, where citrate is used as an anticoagulant. As citrate is metabolized by the liver, the calcium levels may return to normal, but during the period of binding, hypocalcemia can occur, leading to potential symptoms such as muscle spasms or cardiac issues.