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Water and The Electrolytes
By Jennifer Turley and Joan Thompson
© 2016 Cengage
Presentation Overview• Water and minerals in the body• Water functions & importance• Fluid compartments• Intake needs & sources • Output & loss• Dehydration & intoxication• The electrolytes: Na, K, & Cl
Minerals in the Body• Minerals are inorganic elements that are
naturally found in earth.• Major (>5 gm in reference body) & Trace• Major minerals = electrolytes (sodium,
potassium, and chloride)• Major minerals in bone = calcium,
phosphorus, and magnesium• Major mineral in protein = sulfur• Trace minerals = iron, copper, iodine,
manganese, fluoride, chromium, molybdenum, selenium, zinc, & cobalt
Water & Minerals in the Body• Needed in mg or µg amounts (depending on
the nutrient) & based on age, gender, and conditions of pregnancy and lactation.
• Inadequate/deficient intake → deficiency signs/symptoms over time.
• Excess (>UL) intake → toxicity signs/symptoms over time.
• Some foods or food groups provide a good source of some minerals and not others.
• In general, eat a wide variety of foods from each of the food groups & drink fluids to meet mineral and water needs.
Water: Chemical Form
• Water is an inorganic compound composed of two hydrogen atoms and one oxygen atom.
• It is abbreviated chemically as H2O.
Functions of Water in the Body
• A medium for chemical reactions• Participates in energy formation• Regulates nutrients & waste products• Helps regulate body temperature• Lubricants & cushions
– joints, eyes, spinal cord, etc.
• Maintains blood volume
Fluid Compartments
Intracellular
67%Extracellular
25% interstitial
8% blood/plasma
Fluid Balance: Intake Needs
• Adult DRI: ♂ 3.7 liters/day ♀ 2.7 liters/day
There is no UL for water• Another recommend level is 1 ml/Calorie
♂ : 2900 Calories = 2.9 Liters (12 C)
♀: 2200 Calories = 2.2 Liters (9 C)
These may not be optimal fluid intake levels.
Strenuous physical activity & heat stress
greatly increase water needs.
Fluid Turnover Without Perspiration
4% Adults15% Infants
Fluid Sources and Losses (in liters)
Importance of Water
Moments without oxygenDays without waterWeeks without food
~ 60% of total body weight is water
Fluid Balance: Input & Output
• Optimal fluid intake and output leads to normal skin integrity, body weight, urine volume and urine color.
• Enough fluid should be taken in to produce a clear urine output every 2 hours while awake.
• With insufficient intake and obligatory output, dehydration results.
Adverse Effects of Dehydration% Loss Severity Symptoms
1-2 Mild Thirst, fatigue, weakness, loss of appetite
3-4 Moderate Impaired performance, dry mouth, urine reduction, impatience, apathy
5-6 Moderate Headache, irritability, sleepiness, increased respiration
7-10 Severe Dizziness, muscle spasm, imbalance, delirium, collapse
20% water loss is fatal
How to Become Dehydrated
• Intake of caffeine• Intake of alcohol• Diuretic medications• Sweating• Heat exposure
Effects of Dehydration on Health
Chronic Mild Dehydrationis linked to:
• Reduced – Physical Performance– Mental Performance– Salivary Gland Function
• Increased Risk– Urinary tract infection &
stones, constipation, hypertension, heart disease, kidney dysfunction, hyperglycemia with diabetes, and possibly colon and bladder cancer and bronchopulmonary disorders.
Water Intoxication• Rare, usually from forced water intake,• Serious life threatening consequences.• Associated with low blood levels of
sodium (hyponatremia) – CNS edema– lung congestion– muscle weakness– Maximum renal clearance (urinary output) ~700 ml
(24 ounces) -1000 ml per hour.
• With heavy exercise, replace both water and electrolytes.
Sources of Water for the Body100% Water, diet soda
90-99% Nonfat milk, berries, watermelon, celery, lettuce
80-89% Fruit juice, yogurt, apples, oranges, grapes, carrots
70-79% Shrimp, banana, corn, potato, cottage cheese
60-69% Cooked pasta, legumes, salmon, chicken, ice cream
50-59% Ground beef, hot dog
<50% Crackers, cereals, pretzels, nuts, butter, margarine, oils
Met
abol
ic
H 2O
The Electrolytes
• Electrolytes are salts that dissolve in water & dissociate into charged particles called ions.– Sodium: Na+– Potassium: K+– Chloride: Cl-
• Electrolytes function in Fluid/Water balance & acid-base balance (excessive vomiting can cause alkalosis).
Water Follows Electrolytes
Fluid and Electrolytes
• Drinking water & eating regular foods restores fluid & electrolyte balance.
• With excessive sweating, bleeding, vomiting, or diarrhea special drinks may be used to restore electrolytes.
Sodium Deficiency & Toxicity
Food Sources: Salt, sea salt, soy sauce, processed foods, MSG.
Deficiency
(<66% of DRI)
Approx. <990 mg/day
Adequacy
DRI: 1500 mg/day
DRV: 2400 mg
Toxicity
(>UL)
>2,300 mg/day
Cardio-Vascular: hyponatremia, cardiac failureCentral Nervous System: mental apathy, weaknessGI System: loss of appetiteNeuro-Musccular: muscle cramping, skeletal muscle cell injuryOther: renal failure
Normal ECF balance and volume, plasma osmolarity and volume, pH balance, and the membrane potential of cells
Cardio-Vascular: increased blood pressure with increased risk for heart attack and strokeOther: fluid retention (edema)
Adult deficient, adequate, toxic values
Food Processing and Sodium
Adult DRI: 1,500 mg/day
Chloride Deficiency & Toxicity
Food Sources: Salt (~2700 mg/tsp), salt substitute (~2600 mg/tsp), sea salt, soy sauce, processed foods with salt, seaweed,
rye, tomatoes, lettuce, celery, and olives.Deficiency
(<66% of DRI)
Approx. <1520 mg/day
Adequacy
DRI: 2,300 mg/day
(3,800 mg NaCl)
RDI: 3,400 mg
Toxicity
(>UL)
>3,500 mg/day
(5,800 mg NaCl)
Bone & tooth: growth failure in childrenCentral Nervous System: mental apathyGI System: loss of appetiteNeuro-Musccular: muscle cramps
Normal ECF balance and volume and plasma osmolarity and volume. Hydrochloric acid production
Cardio-Vascular: in combination with sodium, increased blood pressure with increased risk for heart attack and stroke
Quantitative data unavailable for graphical analysis
Potassium Deficiency & Toxicity
Food Sources: All whole foods like meats, milk, fruit, vegetables, grains, and legumes, as well as, salt substitute
Deficiency
(<66% of DRI)
Approx. <990 mg/day
Adequacy
DRI: 4,700 mg/day
DRV: 3,500 mg
Toxicity
(UL is Not Established)
Bone & tooth: bone turnoverCardio-Vascular: hypokalemia, cardiac arrhythmia, increased blood pressure with increased risk for heart attack and stroke Neuro-Musccular: muscle weaknessOther: glucose intolerance, risk of kidney stones
Normal ICF volume and function, nerve transmission, muscle contraction, and vascular tone, blunts the rise in blood pressure from excess sodium, and decreases kidney stone reoccurrence
In renal (kidney) failure only.Cardio-Vascular: hyperkalemia, cardiac arrest Neuro-Musccular: muscle tetany
Potassium in Whole Foods
Adult DRI: 4,700 mg/day
Some Summary Points
• Adequate fluid intake is important for health and optimal functioning.
• Dehydration has negative health effects.• Fluid intake should support producing a clear
urine every 2 hours while awake.• The electrolytes function to regulate fluid &
acid-base balance.
References for this presentation are the same as those for this topic found in module 5 of the textbook