Water requirements: Impinging factors and recommended intakes
Introduction
Water is an essential nutrient for all known forms of life and the mechanisms by which fluid and electrolyte homeostasis is maintained in humans are well understood. Until recently, our exploration of water requirements has been guided by the need to avoid adverse events such as dehydration. Our increasing appreciation for the impinging factors that must be considered when attempting to establish recommendations of water intake presents us with new and challenging questions.
This paper, for the most part, will concentrate on water requirements, adverse consequences of inadequate intakes, and factors that affect fluid requirements. Other pertinent issues will also be mentioned. For example, what are the common sources of dietary water and how do they vary by culture, geography, personal preference, and availability, and is there an optimal fluid intake beyond that needed for water balance?