Efficacy of a Naturally Calcium- and Magnesium-Rich Mineral Water on Musculoskeletal Fragility: A Randomized, Double-Blind Controlled Trial

Background/Objectives: Calcium and magnesium are essential minerals involved in neuromuscular function, bone metabolism, and fall prevention. Deficiency of these minerals contributes to musculoskeletal fragility, including osteoporosis, sarcopenia, and falls. While dairy products are the traditional source of dietary calcium, mineral waters naturally rich in calcium and magnesium offer a highly bioavailable alternative. This study evaluated the efficacy of daily intake of a naturally calcium‑ and magnesium‑rich mineral water compared with low-mineral water on fall risk, muscle mass, and muscle function in adults aged ≥50 years, with or without osteosarcopenia. Methods: In this 12‑month, randomized, double‑blind, controlled trial, 98 participants were assigned to consume 1 L/day of either SG9 (mineral water with high calcium and magnesium content) or J66 (low-mineral water). Outcomes included incidence of falls (primary endpoint), appendicular skeletal muscle mass (ASMM), muscle strength, physical performance, biochemical markers, and patient-reported measures. Assessments were performed at baseline, 6 months, and 12 months following CONSORT guidelines. Results: Ninety-eight participants (mean age ~63 years) were randomized and completed the 12-month follow-up. At 6 months, the incidence of falls was significantly lower in the SG9 group compared with the J66 group (relative risk reduction 82%; RR = 0.18, 95% CI 0.04–0.88; p < 0.05), whereas no significant between-group difference was observed at 12 months. Appendicular skeletal muscle mass indexed to height (ASMM/h²) was significantly higher in the SG9 group at 12 months (p = 0.005). In participants with osteosarcopenia, SG9 intake was associated with a consistent improvement in ASMM/h² at 6 and 12 months (p = 0.012 and p = 0.005, respectively). No significant between-group differences were detected in physical performance scores, biochemical markers, or quality-of-life measures. Conclusions: Daily consumption of calcium- and magnesium rich mineral water reduced fall risk and improved muscle mass in adults over 50 years, with or without osteosarcopenia. These findings support the role of calcium- and magnesium-rich mineral water as a complementary nutritional strategy for musculoskeletal health and fragility prevention.