Hydration needs throughout the lifespan.

In 2004, the Institute of Medicine (IOM) issued a report presenting reference intake information about water, sodium, potassium, and other electrolytes for Americans and Canadians. The report established, for the first time, adequate intakes (AI) for total water (from drinking water, beverages, and food) for healthy people. An AI is the recommended average daily intake level based on observed or experimentally-determined approximations or estimates of nutrient intake by a group or groups of apparently health people that are assumed to be adequate. The AI for water is based on US survey data. The recommendations about water intake are for healthy populations--they do not apply to at-risk groups.