Calcic mineral waters contain between 150 mg and 600 mg of calcium per liter, mostly associated with bicarbonates (sparkling water) or sulfates (still water). These waters are interesting sources of calcium, of which intestinal absorption is similar to that of calcium from milk. But that’s where the comparison stops. Calcium in milk is part of a food matrix containing amongst others lactose, phosphopeptides, phosphorus, vitamin D…, that enhances the bioavailability of calcium and guarantees its retention in bones. These favourable conditions are not found in water, often consumed outside meals and without simultaneous intake of phosphorus. Moreover, some waters with high sulfate content boost the loss of calcium through urine.