Tums can be taken by adults and children over 12 by chewing 2-4 tablets as symptoms occur, but you should not take more than 15 tablets in 24 hours, or 10 tablets if pregnant. It is recommended not to use the maximum dosage for more than 2 weeks except under doctor supervision. For most people, Tums (or similar antacids) are taken with or soon after meals, and at bedtime if needed. Long-term daily use is not advised without medical supervision due to potential risks such as kidney problems or calcium imbalance. If you have symptoms persist for more than 2 weeks, it's important to consult a healthcare provider to rule out underlying conditions.