Water & the Electrolytes

By Jennifer Turley and Joan ThompsonBy Jennifer Turley and Joan Thompson© © 20132013 Cengage Cengage

Module 5.3

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 g in 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 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

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 Water/Calorie♂ : 2900 Calories = 2.9 Liters (=12 C)♀: 2200 Calories = 2.2 Liters (=9 C)

Fluid Turnover Without perspiration

Fluid Sources & Losses In liters

Importance of Water 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 MildMild Thirst, fatigue, weakness, loss of Thirst, fatigue, weakness, loss of appetiteappetite

3-4 ModerateModerate Impaired performance, dry Impaired performance, dry mouth, urine reduction, mouth, urine reduction, impatience, apathyimpatience, apathy

5-6 ModerateModerate Headache, irritability, sleepiness, Headache, irritability, sleepiness, increased respirationincreased respiration

7-10 SevereSevere Dizziness, muscle spasm, Dizziness, muscle spasm, imbalance, delirium, collapseimbalance, delirium, collapse

Adverse Effects of Dehydration Intake of caffeineIntake of caffeine

Intake of alcoholIntake of alcohol

Diuretic medicationsDiuretic medications

SweatingSweating

Heat exposureHeat exposure

Effects of Dehydration on Health

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 in the Body

100% Water, diet sodaWater, diet soda

90-99% Nonfat milk, berries, watermelon, celery, lettuceNonfat milk, berries, watermelon, celery, lettuce

80-89% Fruit juice, yogurt, apples, oranges, grapes, carrots Fruit juice, yogurt, apples, oranges, grapes, carrots

70-79% Shrimp, banana, corn, potato, cottage cheeseShrimp, banana, corn, potato, cottage cheese

60-69% Cooked pasta, legumes, salmon, chicken, ice creamCooked pasta, legumes, salmon, chicken, ice cream

50-59% Ground beef, hot dogGround beef, hot dog

<50% Crackers, cereals, pretzels, nuts, butter, margarine, oils Crackers, cereals, pretzels, nuts, butter, margarine, oils

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

K+ is mostlyInside Cells

Na+ & Cl- are mostlyOutside Cells

Na+

O- -H+H+

O-

-H+

H+

O- - H

+H

+

O- -H+H+

Cl-

O- - H

+

H+ O- -

H+H+

O- - H +

H +

O- -

H+

H+

K+

O- -H+

H+

O- - H

+H+

O - -H +

H +

O- -H+

H+

Fluid & 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

SodiumDeficiency & Toxicity

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)

Food Sources: Salt, sea salt, soy sauce, processed foods, MSG.

Sodium & Foods

Adult DRI: 1,500mg/day

ChlorideDeficiency & 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

PotassiumDeficiency & 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 strokeNeuro-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 arrestNeuro-Musccular: muscle tetany

Potassium in Whole Foods

Adult DRI: 4,700 mg/day

Potassium & Foods

Summary 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 3 of the textbook