Mineral water may be a useful means to achieve optimal dietary calcium intake, but the effect of different mineral waters on calcium metabolism is unknown. We therefore evaluated calcium excretion in 24-hour urine in 10 healthy individuals (5 women and 5 men) after two weeks of drinking at least 1500 mL/day of mineral water with a low electrolyte content or 1500 mL/day of mineral water rich in calcium and bicarbonate but with a different sodium content. The low-sodium water Sangemini was one of these two mineral waters. Calcium excretion did not significantly increase after intake of the Sangemini mineral water in comparison with the baseline period of low-electrolyte mineral water intake. Conversely, the calcium excretion increased significantly after intake of the second mineral water. The plasma concentration of C-terminal telopeptide of type I collagen and the urinary phosphate excretion decreased after intake of the second mineral water in comparison with the baseline period, whereas they did not decrease after intake of Sangemini water. Therefore, phosphate excretion was higher after drinking Sangemini water than the other studied mineral water. Drinking Sangemini water may have a slight effect on calcium excretion and may not inhibit bone turnover in the short term. The lesser effect of Sangemini water on calcium excretion could be useful in the treatment of osteoporosis.