2020 · Dose expressed as calcium carbonate. Children 2 to 5 years, weighing >10.9 kg: Oral: 375 to 400 mg of calcium carbonate as symptoms occur for up to 2 weeks; maximum daily dose: 1,500 mg/ day of calcium carbonate. Children 6 to 11 years: Oral: 750 to 800 mg of calcium carbonate as symptoms occur for up to 2 weeks; maximum daily dose: 3,000 mg.