Choice of calcium salt. A comparison of the effects of calcium chloride and gluconate on plasma ionized calcium.

Equimolar quantities of calcium chloride and calcium gluconate produced similar changes in plasma ionised calcium concentration when injected intravenously into anaesthetised ferrets or when added to human blood in vitro. In vivo changes were followed with a calcium electrode positioned in the animal's aorta, and this showed that the ionisation of calcium gluconate on its first pass through the circulation is as great as that of calcium chloride. This does not support the common suggestion that calcium chloride is preferable to calcium gluconate because of its greater ionisation.