Drinking Water

How Much Do We Really Need Everyday?

Nov 8, 2008 Alicia Richardson

You can survive without food for months, but without water, you'd die in a few days. In the body, water becomes the fluid in which all life processes occur.

Water makes up about 60% of the body's weight. It has numerous functions. It:

• Carries nutrients and waste products
• Participates in chemical reactions
• Maintains the structure of proteins
• Serves as a solvent for nutrients, glucose, and various small molecules
• Acts as a lubricant around the joints, inside the eye, spinal cord, and
• Becomes the amniotic fluid surrounding the fetus in the womb
• Aids in temperature regulation
• Maintains normal blood volume.

In healthy adults and children, thirst and urine color indicates whether water requirements are being met. Urine color should be pale yellow unless you're taking multivitamins or riboflavin which fluoresces and turns it bright yellow. Dark yellow means you're probably not drinking enough water. When the body loses 1-2% of its water content, thirst will let you know when it's time to drink water. Your urine should become lighter in color.

Daily Water Recommendations for Healthy Adults and ChildrenThe Institute of Medicine established the Daily Average Intake (AI) for healthy persons in 2004. They are as follows:

• Men 19-70 years: 3.7 Liters/day of total water including 3.0 Liters (13 cups) of water and beverages
• Women 19-70 years: 2.7 Liters/day of total water including 2.2 Liters (9 cups) of water and beverages
• Pregnant Women 14-50 years: 3.8 Liters/day of total water including 2.3 Liters (10 cups) of water and beverages.
• Breastfeeding Women 14 -50 years: 3.8 Liters/day of total water including 3.1 Liters(13 cups) of water and beverages.
• Infants 0-6 months: 0.7 Liters/day of total water assumed to be human milk
• Infants 7-12 months: 0.8 Liters/day of total water including 0.6 Liters (3 cups) of fluids (formula/human milk), juices, and water.
• Children 1-3 years: 1.3 Liters/day of total water including 0.9 Liters (4 cups) of water and beverages.
• Children 4-8 years: 1.7 Liters of total water including 1.2 Liters (5 cups) of water and beverages.
• Boys 9-13 years: 2.4 Liters of total water including 1.8 Liters (8 cups) of water and beverages
• Boys 14-18 years: 3.3 Liters of total water including 2.6 Liters (11 cups) of water and beverages.
• Girls 9-13 years: 2.1 Liters of total water including 1.6 Liters ( 7cups) of water and beverages
• Girls 14 -18 years: 2.3 Liters of total water including 1.8 Liters (8 cups) of water and beverages

Because people's hydration needs depends on their diet, lifestyle, and climate, individual fluid requirements vary widely. Older people may need more drinking water since the "thirst" mechanism slows down in old age, and they may become dehydrated even if they're not thirsty. Athletes also need more drinking water during, before, and after training/competition especially if the event is held outdoors.

Manual labourers who work outside may also need extra drinking water particularly on humid days. Keep in mind, some foods contain significant amounts of fluids (fruits, vegetables, desserts, etc.) that will contribute liquids to your daily requirement. Your thirst mechanism, urine colour, and the recommended water Average Intakes (AIs) should guide your needs. Beyond these parameters, you should consult your physician.

Note: Water does not contain vitamins -unless it's added - but depending on its source, water contains some minerals in significant amounts (sodium, chlorine, magnesium, zinc, copper, and iron), while phosphorus, potassium, molybdenum, iodine, boron, and chromium are present in detectable levels. Also, alcoholic and caffeinated beverages (coffee, tea, carbonated soft drinks) are not good substitutes for drinking water as they act as diuretics.

References

• "Water and the Major Minerals" Whitney EN & Rolfes SR. Understanding Nutrition Wadsworth/Thomson Learning (2002): 367-419
• "Dietary Reference Intakes for Water, Potassium Sodium, Chloride, and Sulfate" The National Academy Press, (2004):73-185

The copyright of the article Drinking Water in Nutrition is owned by Alicia Richardson. Permission to republish Drinking Water in print or online must be granted by the author in writing.

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