Abstract: A novel alkali metal cation-charged, cation exchange resin is provided. The resin includes about 15-50 mEq % of calcium ion, and about 5-13 mEq % of magnesium ion. The calcium ion and magnesium ion loading prevent serious depletion of alkaline earth metal values from body fluids. Also provided is a method of treating a host having hypernatremia or hyperkalemia, using the resin. In one embodiment, the resin includes a supplementary amount of bioavailable calcium ion.