Nutrition for nursing
Dr. Fahad Aldhafiri
‫‪Water‬‬
‫ون)‬
‫ي ٍ أَفَ ََلَيُ ْؤ ِمنُ ََ‬
‫حَ‬
‫ش ْي ٍءَ ََ‬
‫( َو َجعَ ْلنَا ِم ََ‬
‫ن ا ْل َماءَ ُك َّلَ َ‬
• Provides shape and structure to cells. Approximately two-thirds of the
body’s water is located within cells (intracellular fluid).
• Regulates body temperature.
• Aids in the digestion and absorption of nutrients. Approximately 7 to 9 L
of water is secreted in the gastrointestinal tract daily to aid in digestion
and absorption.
• Transports nutrients and oxygen to cells.
• Serves as a solvent for vitamins, minerals, glucose, and amino acids.
• Participates in metabolic reactions. For instance, water is used in the
synthesis of hormones and enzymes.
• Eliminates waste products.
• Is a major component of mucus and other lubricating fluids.
Water balance
• Water balance is the dynamic state between water output and water
intake. Under normal conditions, output and intake are approximately
equal.
Water Output
• On average, adults lose approximately 1750 to
3000 mL of water daily.
• Extreme environmental temperatures (very
hot or very cold), high altitude, low humidity,
and strenuous exercise increase insensible
water losses (immeasurable losses) from
respirations and the skin.
• Sensible water losses (measurable losses) from urine
and feces make up the remaining water loss. Because
the body needs to excrete a minimum of 500 mL of
urine daily to rid itself of metabolic wastes, the
minimum daily total fluid output is approximately
1500 mL.
• To maintain water balance, intake should
approximate output.
Water Intake
• Total water intake averages about 2½ liters per day,
of which approximately 80% is from fluids and 20%
from solid food.
Inadequate Fluid Intake
• An inadequate intake of water can lead to
dehydration, characterized by impaired mental
function, impaired motor control, increased body
temperature during exercise, increased resting heart
rate when standing or lying down, and an increased
risk of life-threatening heat stroke.
• Clinical situations in which water losses are
increased—and thus water needs are elevated—
include vomiting, diarrhea, fever, thermal injuries,
uncontrolled diabetes, hemorrhage, certain renal
disorders, and the use of drainage tubes.
Excessive Fluid Intake
• A chronic high intake of water has not been shown to
cause adverse effects in healthy people who
consume a varied diet as long as intake approximates
output .
• An excessive water intake may cause hyponatremia,
but it is rare in healthy people who consume a typical
diet.