Magnesium content in mineral water varies widely by brand and spring source, so the most accurate method is reading the label. Even within the same country, some waters contain only a few mg/L, while others can reach 50–120 mg/L or more. Look for “Mg (mg/L)” on the mineral composition panel. Two practical tips: (1) note the magnesium value of your regular brand, and (2) also check sodium—high-sodium waters may not be ideal for people with hypertension or salt restrictions. Mineral water can contribute to intake, but it rarely replaces a magnesium-rich diet.