Nutrition Science and Everyday Application - beta v 0.1

Vitamins and Minerals Involved In Fluid And
Electrolyte Balance
Water is the foundation of all life. The surface of the earth is 70% water, and human beings
are mostly water, ranging from about 75% of body mass in infants, 50–60% in adults, and
as low as 45% in old age. (The percent of body water changes with development, because
the proportions of muscle, fat, bone, and other tissues change from infancy to adulthood.)
Of all the nutrients, water is the most critical, as its absence proves lethal within a few
days. The importance of water in the human body can be loosely categorized into four basic
functions: transportation vehicle, medium for chemical reactions, lubricant/shock absorber,
and temperature regulator.
Maintaining the right level of water in your body is crucial to survival, as either too little or
too much will result in less-than-optimal functioning. Several minerals are key to regulating
water balance in different compartments of the body; the most important of these are
sodium, potassium, and chloride.
WATER DISTRIBUTION AND COMPOSITION
In the human body, water is distributed into two compartments: inside cells, called
intracellular fluid (ICF), and outside cells, called extracellular fluid (ECF). Extracellular fluid
includes both the fluid component of the blood (called plasma) and the interstitial fluid (IF)
that surrounds all cells not in the blood (Figure 8.6).
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