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Calcium Bioavailability from Mineral Waters with Different Mineralization in Comparison to Milk and a Supplement

Greupner, Theresa, Schneider, Inga, Hahn, Andreas
Journal of the American College of Nutrition 2017 v.36 no.5 pp. 386-390
bicarbonates, bioavailability, blood serum, calcium, cross-over studies, excretion, food science, human nutrition, men, milk, mineral water, mineralization, phosphates, sulfates, women
Objective : The aim of the present study was to compare the bioavailability of calcium from 3 mineral waters with different concentrations of minerals with that of milk and a calcium supplement. Methods : A single-center, randomized controlled trial with a crossover design with 21 healthy men and women was conducted at the Institute of Food Science and Human Nutrition, Leibniz University Hannover. The participants consumed the 5 test products providing 300 mg of calcium each on 5 examination days with 1-week wash-out phases in between. Primary outcome variables were the area under the curve of serum calcium levels for 10-hour (AUC ₀–₁₀ₕ) and 24-hour urinary calcium excretion. Results : In all groups, no significant differences in the AUC ₀₋₁₀ₕ of serum calcium levels as well as in the 24-hour urinary calcium excretion were observed. Likewise, mean changes in serum phosphate and urinary phosphate, as well as serum parathormone, showed no differences between the groups. Conclusion : Given an equivalent bioavailability of calcium in all test products, neither a high concentration of SO ₄²⁻ or of HCO ₃ influenced the bioavailability of calcium. Accordingly, the use of mineral water with high concentrations of calcium constitutes a calorie-free calcium source that can improve calcium supply.