Alkali supplements decrease bone resorption and increase bone mineral density. Alkali diets also lower bone resorption. Mineral waters alone could have such an effect. In several subsequent studies in humans, bicarbonate-rich alkali mineral waters with low potential renal acid load values were shown to decrease bone resorption markers and even parathyroid hormone levels. This effect seems to be stronger than that of acidic calcium-rich mineral waters and could also be demonstrated in calcium sufficiency.