Calcium and Magnesium in Distributed Water in Restaurants of Land Forces in France

Samples of distributed water have been taken from 127 restaurants of the land forces selected in different administrative districts in France to assess the contribution of water to recommended daily allowances (RDA) in calcium and magnesium. Mean levels of calcium and magnesium were found to be, respectively, 63.8±37.7 and 5.4±2.5 mg/l, with a significant correlation between calcium and magnesium content (r=0.49, P<0.001). The softest waters are found in areas where soil is granitic or sandy. Daily consumption of 1 l of tap water provides on an average 7.1 and 1.3% of RDA in calcium and magnesium.