Effects of mineral and curative waters on bone health: Physiology and epidemiological evidence

Mineral waters and medicinal waters are characterised by their specific composition, which makes them different from a nutritional point of view. Many mineral and medicinal waters are a quantitatively significant source of readily bioavailable calcium and magnesium. Calcium-rich waters are therefore a favourable alternative to readily soluble calcium citrate, which is recommended by the guideline of the Bone Health & Osteoporosis Foundation as a source of calcium in cases of achlorhydria or restricted gastric acid production (e. g. therapy with proton pump inhibitors). Calcium waters lower serum parathyroid hormone similarly to calcium from milk or supplements with equivalent mineral content. Moreover, alkaline calcium waters inhibit bone resorption. Bicarbonate-rich waters also reduce renal acid load and, as a result, urinary calcium losses. However, the waters effect on calcium balance and fracture risk is unclear. Besides, the sodium and potassium content of most waters is too low to have a significant effect on bone metabolism. Even waters with a moderate fluoride content (0.70-1.0 mg/l) have no effect on bone microstructure, independent of other dietary factors (calcium, protein).