Water: The Essential Nutrient
Water: The Essential Nutrient
Joy Stepinski, MSN, RN-BC
April 19, 2026
The month of April always makes me think of water. As one of the rainiest months of the year, the drizzle and downpour bring life to the newly forming plants and blooming flowers. Without sufficient water, the plants would wither and struggle to survive. Not only is water necessary for the plant kingdom, but also vital for humans. Adequate intake is required for proper body function and overall health.
Water is considered the most essential nutrient for life. The word essential means of the utmost importance. An essential nutrient obtained from the diet when the molecule is not produced by the body in enough quantity to sustain life [1]. The body cannot make enough water on its own to survive.
The content of water in the body is significant. Approximately 60% of body weight is composed of water, depending on body fat composition and age. Infants, for example, have a higher percentage of body water [2]. In adults, two-thirds of the total water is found inside cells, while only one-third exists outside the cells. Examples of extracellular fluid are blood plasma, cerebrospinal fluid, and lymph fluid.
Water serves many functions in the body. As the primary component in cells, tissues, and organs, it acts as a solvent for substances like glucose and amino acids. Water breaks down carbohydrates, proteins, and fats. As a transporter, water carries nutrients to cells, removes waste, and provides the medium for cellular exchange. As a contributor to thermoregulation, water helps to maintain temperature through sweating. Water lubricates joints and allows the digestive and respiratory tract to function properly.
Without adequate hydration, the human body can face severe consequences. In the coming months, we will examine ways that hydration maintains and impacts health. May the spring rain serve as a reminder that water has an essential role in sustaining life.
References:
Merriam-Webster. (2026). Essential. https://www.merriam-webster.com/dictionary/essential
Jéquier, E., & Constant, F. (2010). Water as an essential nutrient: the physiological basis of hydration. European Journal of Clinical Nutrition, 64(2), 115-123.