Twenty-Four-Hour Urine Osmolality as a Physiological Index of Adequate Water Intake

While associations exist between water, hydration, and disease risk, research quantifying the dose-response effect of water on health is limited. Thus, the water intake necessary to maintain optimal hydration from a physiological and health standpoint remains unclear. The aim of this analysis was to derive a 24 h urine osmolality (U Osm ) threshold that would provide an index of “optimal hydration,” sufficient to compensate water losses and also...