Magnesium Water: Higher Bioavailability if Consumed Throughout the Day?

Waters and sports beverages that are high in magnesium are sprouting up in health food stores and super markets. This begs one question: is a single dose of lots of magnesium any better (or worse) than consuming that same amount in modest portions throughout the day?

Nestlé researchers sought to answer that question. Their findings are now available in the British Journal of Nutrition.

Twenty-five men were assigned to drink 1.5 liters of Contrex, a mineral water naturally enriched with 126 mg of magnesium throughout the course of a day either as 2 servings of 750 mL or 7 servings of 212 mL.

One day of crossover allowed for all subjects to participate in both regimens. Two stable isotopes (²⁵Mg and ²⁶Mg) were used to distinguish each regimen in the body.

Data findings indicate that magnesium absorption and retention improved with seven servings compared to the two larger servings. Absorption improved by an average of 25% and retention improved by an average of 19%.