Kin 110

1
Kin 110

• Lecture 8
• Ch. 8 Water and Minerals

2
Overview

• Water - 50 - 70 of the body
• medium for chemical reactions, temperature
  regulation and lubrication.
• 1 ml/ kcal expenditure
• Minerals - many are vital to sustaining life
• Know function, source and possible dysfunction
• Major - gt 100 mg/day
• Trace - lt 100 mg/day
• both equally necessary

3
Water

• Forms ideal medium for body processes
• 50 - 70 of human body, most abundant nutrient
• lean muscle 73
• adipose 20
• you can only survive for a few days without water

4
Water in the Body

• Flows freely in and out of cells
• Intracellular fluid
• water inside cells (25L)
• Extracellular fluid
• water outside cells (14L)
• water in bloodstream (3L)
• body controls of amount of water inside and
  outside cells through regulation of ion
  concentration and movement

5
Control of Body Water

• Ions have electrical charge
• attracts water, where ions go, water follows
• Osmosis - process that regulates and equalizes
  proportions of water in cells and blood stream
• fluids in different ion concentrations surround a
  semipermeable membrane

6
Control Continued

• Semipermeable membrane (cell membrane)
• allows water to passively diffuse
• regulates ion flow though opening and closing of
  channels and the use of pumps
• water flow to equalize concentration of ions on
  either side of membrane

7
Ion balance

• Pumps maintain high potassium (K) and Phosphate
  (P) inside the cell
• maintain high sodium (Na) and chloride (Cl)
  outside the cell.

8
Temperature Regulation

• Water changes temperature very slowly
• requires a lot of energy to change states (liquid
  to gas)
• ideal for removing heat from the body surface by
  evaporation
• body secretes perspiration, requires energy to
  evaporate, cooling the skin 600kcal/L
• requires low humidity

9
Removal of Waste

• Most unusable substances dissolve in water and
  are eliminated in urine
• Urea - major body waste product (nitrogen based)
• produced by protein metabolism
• increase sodium and protein intake, increase
  urine output
• 1 - 2 L per day
• low urine output, becomes concentrated, risk
  kidney stones

10
How Much Water?

• approximately 1 ml/kcal
• 1L of fluid plus 1L from food
• produce 1.5 cups through metabolic processes
• 2400 ml for 2400 kcal
• use 1.4 L for urine
• use 1 L in insensible water loss
• lungs, skin, GI
• Massive conservation of water by kidneys and GI

11
Thirst

• Triggered with loss of 1 - 2 of body fluid
• athletics, infants, elderly, air travel, illness
  (fever, diarrhea)
• Low water
• ADH (anti diuretic hormone)
• triggers kidneys to conserve water
• Alcohol inhibits ADH, lose water, manifest
  symptoms of low water

12
Minerals

• Metabolic roles and required amounts are highly
  variable (Fig. 8-4)
• cofactors
• enable enzymes to function copper, selenium
• part of body compounds
• iodide - thyroid hormone
• iron - hemoglobin, myoglobin
• transfer of nerve impulses
• sodium, potassium, and calcium
• muscle contraction (calcium)
• Body growth and development
• calcium and phosphorus

13
Mineral Bioavailability

• Degree to which the amount of an ingested
  nutrient is absorbed and is available to the body
• eg. Only 5 of the calcium in spinach is
  absorbed
• due to presence of oxaloacetate (binder)
• minerals from animal sources are, in general,
  absorbed better
• plant absorption affected by binders and fiber
  interactions

14
Mineral Binders

• Fiber binds to Zinc, Iron and Magnesium
• (moderate fiber intake)
• yeast frees zinc, increasing absorption
• high content of one mineral can reduce the
  absorption of another
• high zinc - dec. copper
• (moderate supplement intake)
• (toxicity possible with many minerals)

15
Major Minerals

• Needed in excess of 100mg/day
• Sodium (Na)
• function - major () ion in extracellular fluid
  and key factor for retaining body water and fluid
  balance
• nerve impulse conduction and nutrient absorption
  (glucose)
• Low sodium -
• muscle cramps, nausea, vomiting, dizziness,
  shock , coma.

16
Sodium

• Low sodium more likely with excess perspiration,
  illness
• not much of a concern due to very high intake
• endurance athletes may need to add salt, take
  sports drinks
• RNI 500 mg/day (avg. 3-6000)
• 10 - 15 of adults are sodium sensitive, excess
  intake can lead to high blood pressure

17
Potassium (K)

• Similar functions as sodium
• found inside cells
• low K (diuretics)
• loss of appetite, muscle cramps, confusion, heart
  irregularities
• fruits and vegetables are good sources
• Milk, whole grains, meat
• RNI 2 g/day (avg 2-3)
• high levels not toxic with proper kidney
  function, otherwise can lead to heart failure

18
Chloride (Cl)

• Important negative ion in extracellular fluid
• hydrochloric acid in stomach
• attack on foreign cells
• nerve function
• insufficiency very rare
• salt is 60 Cl
• RNI 700 mg, avg. 4500 mg

19
Calcium (Ca)

• Required by all cells
• 99 to strengthen bones and teeth
• growth and bone development requires calcium
• absorbed in first part of SI (more acidic)
• requires vitamin D hormone
• postmenopausal women may need estrogen therapy to
  help make vitamin D hormone

20
Calcium

• Absorption inhibited by some fiber, high
  phosphorus and tea
• excellent hormonal regulation for blood calcium
• at expense of bones
• significant loss over several years
• Functions
• bones and teeth
• blood clotting, muscle contraction
• nerve transmission, messenger and hormone
  signaling
• Possibly preventative role for calcium in colon
  cancer, blood pressure and blood LDL

21
Calcium Sources

• Dairy products (except cottage cheese)
• leafy greens, sardines, fortified orange juice,
  cereals
• RDA 1000mg (higher for teens)
• many women have intake below average
• rule of 300s
• excess intake
• over 2000 mg
• high BP, irritability, headache, kidney failure,
  soft tissue calcification, kidney stones

22
Phosphorus (P)

• High absorption and availability
• may contribute to bone loss in elderly
• involved in enzymes and key metabolic compounds
• ATP, DNA, membranes and bones
• Dairy, baked goods, and mead
• additive in soft drinks
• RNI 800mg avg. 9-1700mg
• vegans, alcoholics, elderly

23
Magnesium(Mg)

• Nerve and heart function and aids in many enzyme
  reactions
• deficiency leads to irregular heart beat,
  weakness, muscle pain, disorientation and seizure
• may be linked to heart attack
• sources - plant products
• whole grains, broccoli, squash
• RNI 300mg avg. 300mg
• diuretics and alcoholism

24
Trace Minerals

• Require smaller amounts, but they are just as
  essential to good health
• most recent discoveries in nutrition relate to
  trace minerals
• defining needs is difficult due to minute amounts
  
• Table 8-5

25
Iron (Fe)

• Most common deficiency
• found in every cell mainly for oxygen,
  hemoglobin/myoglobin
• several means to regulate absorption
• heme iron most readily absorbed (animal sources)
• non-heme iron
• eggs, milk, vegetables, grains
• lower absorption, enhanced by heme iron and
  vitamin C

26
Iron Deficiency Anemia

• Reduced red blood cells, lower hematocrit,
  reduced oxygen capacity
• fairly common
• symptoms
• pale skin, fatigue, poor temperature regulation,
  loss of appetite, apathy
• may decrease learning ability, attention span,
  work performance and immune status

27
Iron

• Sources
• spinach, oysters, clams, peas and legumes
• consider bioavailability, animal sources are best
• RNI
• 10mg (men) 15mg (women)
• absorption reduced by tea, fiber, zinc and
  calcium
• Toxicity

28
Zinc(Zn)

• Functions
• many enzymes require zinc for optimal activity
• DNA synthesis and protein metabolism, wound
  healing and growth
• proper immune function
• development of sexual organs and bone
• insulin storage and release
• cell membrane structure and function

29
Zn deficiency

• Symptoms
• acne, diarrhea, reduced appetite and sense of
  taste and smell
• reduced growth, sexual development and learning
  ability
• protein rich foods, oysters, shrimp, crab beef,
  lamb, turkey beans, mushrooms, peanuts
• animal sources highest absorption
• RNI 15mg/12 mg, many have marginal intake

30
Selenium

• Reduces damage from free radicals
• contributes to thyroid hormone metabolism
• deficiency - muscle pain and wasting - heart
  disease
• sources - fish, meats eggs, shellfish
• grains and seeds - depending on soil
• RDA - 55-70 ug avg 110ug
• toxicity with 900ug for extended periods
• garlic breath, hair loss, nausea, weakness
• supplements over 200ug not advised

31
Iodide (I)

• Ion form iodide
• deficiency related to goiter, added to salt
• very high frequency of deficiency
• Function
• supports hormone synthesis in thyroid gland
• regulates metabolic rate, promotes growth and
  development
• cretinism with fetal deficiency

32
Iodide

• Sources of I
• salt water fish, seafood, iodized salt, dairy and
  grain
• Sea salt, not a source of iodide
• most consume well over RDA, not counting table
  salt

33
Copper(Cu)

• Functions
• Metabolism of iron
• connective tissue protein
• antioxidant enzymes
• immune system function
• Sources
• seafood, cocoa, legumes, nuts and seeds, whole
  grain
• generally good intake

34
Fluoride(F)

• Functions
• synthesis of tooth crystal that is resistant to
  acids
• inhibits growth of bacteria
• both reduce dental carries (cavities)
• many communities have fluoride added to water
• Sources
• tea, seafood, seaweed

35
Chromium(Cr)

• Function
• maintenance of glucose uptake
• lose control of glucose with deficiency
• supplements may aid type 2 diabetes
• Sources
• egg yolks, bran, meat, mushrooms, nuts and beer
• high risk of toxicity
• industrial and artistic exposure
• liver damage, lung cancer