Water

1
Water the Minerals

• Readings
• Chapter 11 Chapter 12
• Omit details p 463 - 465
• Omit details in figs 11.4,11.6, 11.7, 11.10,
  11.11, 11.21
• Omit the sections on Manganese, Molybdenum,
  and Other Trace Elements and Ultratrace Elements

2
Water
99 lb water

• Water is the most indispensable nutrient.
• Our bodies are made of about 50 - 75 water.

27 lb protein
24 lb fat
10 lb minerals glycogen
160 lb man
3
Functions of Water

• transport of nutrients waste compounds
  throughout body
• maintains the structure of large molecules
• participation in metabolic reactions
• solvent for minerals, vitamins, amino acids,
  glucose, and other small molecules
• lubrication and cushioning of joints, eye, spinal
  cord
• regulates body temperature
• maintains blood volume blood pressure

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Functions of Water
5
Water in the Body
extracellular fluid
intracellular fluid
interstitial fluid
plasma
6
Water Sources
Metabolism 200 - 300 ml
Liquids 550 - 1500 ml
Foods 700 - 1000 ml
Total 1450 - 2800 ml
7
Water in Selected Foods

• chicken breast or salmon 60
• cooked white rice 70
• bread 40
• pears 85

8
Water Intake

• Recommendations
• 11.5 ml water/kcal of energy expended
• Example
• energy expenditure 2000 kcal/day
• water needs 2000 - 3000 ml water/day
• Note
• alcoholic beverages, soft drinks, and beverages
  containing caffeine are NOT good substitutes for
  water
• act as diuretics

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Water Intake

• Healthy choices
• Less healthy choices

10
Tap vs. Bottled Water?

• in NA, bottled water is regulated by similar
  standards as for tap water
• in fact, some tap regulations arent imposed on
  bottled water
• 40 of bottled water is just processed tap water
• it costs 10,000 times more to produce bottled
  than it does tap water
• Some people do not like taste of tap water.
• Leave on counter to allow chlorine to evaporate
• GVRD recommends letting tap water run for a
  minute if it has been off for several hours.
• Is bottled water better?

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Water Excretion
Feces 150 ml
Lungs 350 ml
Kidneys 500 - 1,400 ml
Skin 450 - 900 ml
Total 1450 - 2800 ml
12
Dehydration

• occurs when water loss exceeds water intake
• may result from excessive water loss or
  inadequate intake
• onset severity of symptoms depend on activity,
  fitness level, acclimatization, temperature,
  humidity
• leads to failure to regulate body temperature,
  causing hyperthermia
• electrolyte imbalances contribute to cardiac
  arrhythmias death

13
Dehydration
Weight Lost Symptoms
1-2 thirst, fatigue, vague discomfort, loss of appetite
3-4 impaired physical performance, dry mouth, reduction in urine, flushed skin, impatience, apathy
5-6 difficulty concentrating, headache, irritability, sleepiness, impaired temperature regulation, increased respiratory rate
7-10 dizziness, muscle spasms, loss of balance, delirium, exhaustion, collapse
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Water Intoxication

• excess consumption of water may lead to dilution
  of the sodium concentration in the blood causing
  hyponatremia
• children, elderly are most at risk problem also
  has a higher incidence in endurance athletes

15
Thirst

• most important stimulus for drinking
• stimuli for thirst are
• reduced blood volume blood pressure
• - Athletics, infants, elderly, air travel,
  illness (fever, diarrhea)
• - Also triggered with high salt intake
• - dryness of the mouth mucous
• membranes lining the esophagus
• Response
• ADH (anti diuretic hormone)
• Triggers kidneys to conserve water
• Strong alcohol inhibits ADH, lose water, manifest
  symptoms of low water.

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Substances that Affect Fluid Balance

• Alcohol
• suppresses ADH secretion, increasing fluid loss
• excessive consumption can lead to dehydration, a
  key contributing factor to many of the symptoms
  of a hangover
• - Aspirin does not help hangovers
• Drinking less alcohol does
• Caffeine
• inhibits the activity of ADH, increasing fluid
  loss (still net gain of fluid)

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Introduction to the Minerals

• inorganic elements
• some travel freely, others require transporters
• often interact with each other
• have many and various functions

18
Mineral Bioavailability
Nutritional status (needs)
Interactions with other minerals
Fibers, Phytates, Oxalates
Intestinal Acidity
Polyphenols
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Sodium (Na)

• Functions
• principle cation of the ECF primary regulator
  of ECF volume
• helps maintain acid-base balance
• essential for electrical signaling in nerves and
  muscles
• Recommendations
• Can 115 mg/day minimum US 500 mg/day
• AI 1500 mg Daily Value 2400 mg
• 1 tsp table salt 2000 mg sodium

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Sodium in Foods

• processed foods contain the most sodium
• 75 of sodium in average North American diet
  from processed foods
• 15 from salt added during cooking at table
• only 10 from sodium naturally present in food
• 1 oz Cornflakes contains more sodium than 1 oz
  salted peanuts
• ½ cup instant chocolate pudding contains more
  sodium than either the cornflakes or the peanuts

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Sodium in Foods
22
Sodium (Na)

• Deficiency
• does not result from inadequate intake!
• may occur due to excessive loss caused by
• vomiting
• diarrhea
• heavy sweating during physical activity
• may lead to hyponaturemia
• symptoms include muscle cramps, mental apathy,
  loss of appetite
• replaced through food or beverages containing
  both sodium glucose

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Sodium (Na)

• Toxicity
• acute symptoms include edema hypertension
• prolonged excessive intake MAY contribute to
  hypertension in salt-sensitive individuals
• salt restriction in combination with a diet rich
  in fruits vegetables decreases blood pressure
  in these individuals
• high sodium intake also linked with an excess of
  calcium excretion in the urine

24
Potassium (K)

• principle cation of the intracellular fluid
• important for electrical signaling of nerves and
  muscles
• helps regulate heart rate blood pressure
• a diet LOW in potassium is associated with an
  INCREASED risk of hypertension
• potassium rich fruits and vegetables linked to a
  decreased risk of stroke
• AI 4700 mg Daily Value 3500 mg

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Potassium (K) Food Sources

• best food sources
• fresh foods, especially fruits and vegetables
• potassium is LOST with food processing

26
Potassium (K)

• Deficiency
• rare as a result of dietary insufficiency!
• hypokalemia most common electrolyte imbalance
• may result from excessive loss associated with
  heavy sweating, vomiting, or diarrhea
• symptoms include muscular weakness, paralysis,
  confusion
• Toxicity
• result of consumption of supplements

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Effect of Food Processing on the Mineral
Composition of Foods
28
Chloride (Cl-)

• important ion in the extracellular fluid
• maintains fluid and electrolyte balance
• forms part of hydrochloric acid (HCl) in the
  stomach
• diets rarely lack chloride
• losses may occur with excess sweating, chronic
  diarrhea, or vomiting
• loss of Cl- H produces metabolic alkalosis
• blood concentrations may rise with severe
  dehydration

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Calcium (Ca2)

• most abundant mineral in the body (99 of calcium
  is contained within our bones)
• maintains bone structure
• serves as a pool to maintain calcium levels
  elsewhere in the body
• Recommendations
• Adolescents
• Adults

1300 mg/day
1000 mg/day
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Calcium Functions
trabecular bone

• with phosphorous forms a crystal called
  hydroxyapatite
• attaches to a collagen matrix to mineralize bones
  and teeth
• gives bones their strength and rigidity

cortical bone
31
Calcium Functions

• ionized calcium also important for
• muscle contraction
• heart function
• nerve function transmission of nerve impulses,
  release of neurotransmitters from nerve cells
• blood clotting formation of fibrin
• regulation of blood pressure
• intracellular signaling binds with calmodulin
• activating enzymes and regulating various
  processes ie. hormone secretion

32
Calcium Sources

• most abundant in milk and other dairy products
• non-dairy sources include
• cauliflower
• bok choy
• broccoli
• fortified soy products
• canned fish with bones
• bone soup stock

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cauliflower, watercress, Chinese cabbage, head
cabbage, brussels sprouts, rutabaga, kolhrabi,
kale, mustard greens, bok choy, broccoli, turnip
greens, calcium fortified foods and
beverages milk, calcium-fortified soy milk,
calcium-set tofu, cheese, yogurt almonds, sesame
seeds, pinto beans, sweet potatoes spinach,
rhubarb, Swiss chard

• 50 absorbed
• 30 absorbed
• 20 absorbed
• ? 5 absorbed

34
Calcium Deficiency

• low calcium intake during growth prevents bone
  from reaching optimal mass and density ?
  development of osteoporosis later in life
• with inadequate calcium intake, blood calcium
  concentrations are maintained at the expense of
  bones
• low blood calcium hypocalcemia
• not a result of low calcium intake!
• causes include kidney failure, parathyroid
  disorders, Vitamin D deficiency
• may lead to muscle spasms, convulsions

35
Calcium Toxicity

• symptoms include constipation and increased risk
  of kidney stones
• excess calcium also interferes with the
  absorption of other minerals
• e.g. iron, magnesium, zinc
• high blood calcium hypercalcemia
• not caused by excessive intake!
• primary causes usually cancer, overproduction of
  PTH, or excess Vitamin D
• effects include fatigue, confusion, loss of
  appetite, constipation, and calcification of
  tissues

36
Phosphorous (P)

• second most abundant mineral in the body
• with calcium forms hydroxyapatite crystals of
  bones and teeth
• other important functions include
• buffers pH
• part of DNA, RNA, phospholipids, and some
  proteins
• assists in energy metabolism part of ATP
• activation and deactivation of enzymes through
  phosphorylation reactions
• deficiency and toxicity are rare

37
Phosphorous Sources
Chick peas and other legumes
Milk and dairy products
Salmon, tuna, cod and other fish
Steak, liver, and other meats
38
Hypophosphatemia

• low blood phosphate
• not a result of dietary insufficiency!
• common causes include
• hyperparathyroidism, Vitamin D deficiency,
  overuse of antacids that bind phosphate
• symptoms may include
• anorexia, dizziness, bone pain, muscle weakness,
  waddling gait
• chronic hypophosphatemia leads to
• muscle weakness and damage, respiratory problems,
  rickets, osteomalacia

39
Hyperphosphatemia

• high blood phosphate
• not a result of excess consumption
• commonly a consequence of kidney disease
• may also result from
• an underactive parathyroid gland, excess Vitamin
  D supplements, or overuse of phosphate-containing
  laxatives
• excess phosphate may bind calcium leading to
  muscle spasms and convulsions

40
Magnesium Functions

• important as a cofactor for metabolism and
  required for protein synthesis
• essential for the production of ATP by the
  electron transport chain
• holds calcium in tooth enamel
• participates in muscle contraction and blood
  clotting
• protects against hypertension heart disease
• supports normal functioning of the immune system

41
Magnesium Sources
Legumes
Oysters
Spinach
Sunflower seeds
Figs
Potatoes
42
Magnesium Sources

• refined foods lose Mg2 during processing
• not added back with enrichment
• hard tap water may be a significant source
• about 50 of magnesium is absorbed
• high fiber foods containing fermentable
  carbohydrates (resistant starches,
  oligosaccharides, and pectin) increase magnesium
  absorption
• high Ca2 intake (e.g. from supplements) can
  interfere with absorption of Mg2

43
Hypomagnesia

• usually only occurs with disease (e.g. kidney,
  alcoholism, prolonged diarrhea)
• symptoms include weakness, tetany, impaired
  functioning of the central nervous system,
  cardiac arrhythmias
• Hypermagnesia
• uncommon in the absence of kidney disease
• results in nausea, weakness, diarrhea,
  dehydration and alkalosis

44
Sulfur

• not found alone as a nutrient
• in body, exists as a component of other organic
  compounds (e.g. thiamin, biotin, methionine,
  cysteine)
• important for protein structure
• permits the formation of disulfide bridges that
  help proteins fold in specific ways
• obtained in diet through consumption of sulfur
  containing amino acids
• deficiency is unknown in humans

45
Trace Minerals An Overview

• only in miniscule amounts
• content in foods depends on soil content, water
  composition, food processing
• interactions among trace minerals are common
• the trace minerals include iron, zinc, iodine,
  selenium, copper, fluoride, chromium, molybdenum
  manganese

46
Iron

• exists in two forms
• reduced or ferrous iron (Fe2)
• oxidized or ferric iron (Fe3)
• Functions
• forms part of electron carriers called
  cytochromes in the ETC (metabolism)
• forms part of proteins hemoglobin myoglobin
• required by enzymes that synthesize collagen,
  hormones, neurotransmitters, and amino acids
• important for immune function

47
Iron in Foods

• Types of Iron
• heme
• from food derived from animal food sources
• 25 absorption
• non-heme
• from both animal and plant derived foods
• only 10 is absorbed

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Iron Sources
3 oz steak 3 mg 3 oz liver 3 mg ½ cup clams
22 mg 3 oz shrimp 2 mg
Best source per kcal
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Iron Sources

• Others
• broccoli, spinach, dried fruits, eggs, legumes,
  enriched grains and cereals
• Contamination Iron
• iron found in foods as the result of
  contamination by inorganic iron salts from iron
  cookware or iron containing soils
• Recommendations
• Men
• Women

8 mg per day
18 mg per day
50
Iron Absorption
Factors Enhancing Absorption Factors Inhibiting Absorption

MFP factor Vitamin C citric, malic lactic acid HCl acid sugars high fiber diet phytates oxalates calcium and phosphorous EDTA Tannins (found in tea)
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Iron Absorption Metabolism

• iron is not readily excreted
• balance is maintained by adjusting absorption
• ? iron stores, ? iron absorption

53
Iron Transport Storage

• the intestine absorbs iron and stores it in
  protein called mucosal ferritin
• iron that is not needed is lost when intestinal
  cells are shed
• when body needs iron, it is moved to another
  protein transferrin
• transports iron to the rest of the body where it
  is needed, such as the bone marrow where red
  blood cells are synthesized
• think transferrin transport

54
Iron Transport Storage cont.

• surplus is stored in ferritin in the liver, bone
  marrow and spleen
• even greater concentrations of iron lead to
  storage of iron in another protein called
  hemosiderin
• storage important to prevent free iron from
  acting as a free radical

55
Iron Deficiency

• most common nutrient deficiency world wide
• Ways Iron is Lost from the Body
• some iron is lost daily from the digestive tract
• only tiny amounts lost through feces, urine,
  sweat and shedding skin
• blood loss

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Iron Deficiency cont.

• Stages in the Development of Deficiency
• iron stores diminish
• measured by assessing serum ferritin
• levels of functional iron decrease
• decreased transferrin saturation
• accumulation of erythrocyte protoporphyrin
• iron deficiency anemia microcytic hypochromic
  anemia
• production of hemoglobin decreases
• decrease in hematocrit
• decrease in red blood cell size

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Iron Deficiency cont.

• Symptoms
• microcytic hypochromic anemia
• red blood cells are small and pale
• results in fatigue, weakness, headaches, pallor,
  poor resistance to cold
• cognitive impairment, behavioural changes,
  reduced learning ability

Anemic
Normal
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Iron Toxicity

• iron absorption decreases when body needs
  decrease
• excess iron is referred to as iron overload
• Hemochromatosis
• hereditary disorder characterized by enhanced
  iron absorption
• Hemosiderosis
• due to long-term overconsumption of iron
• characterized by deposits of hemosiderin in
  tissues

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Iron Toxicity cont.

• Symptoms Consequences
• tissue damage, deposits of iron
• apathy, lethargy and fatigue
• increased infections
• increased risk of heart disease
• free iron acts as a pro-oxidant
• may oxidize LDL and contribute to development of
  atherosclerosis
• increased risk of cancer
• increased free radical formation may contribute
  to DNA damage

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Iron Toxicity cont.

• Symptoms Consequences
• poisoning in children if ingest supplements

Which are candies and which are supplements?
Iron Supplements
61
Zinc Functions

• acts as a cofactor for many enzymes
• Example metalloenzymes
• assists in immune function
• important for growth and development
• required for DNA and RNA synthesis
• synthesis of heme in hemoglobin
• releases Vitamin A from stores and converts to
  its active form
• forms part of an antioxidant enzyme that protects
  from free radicals zinc superoxide dismutase

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Zinc Functions cont.

• stabilizes cell membranes and helps protect them
  from free radical attack
• interacts with platelets in blood clotting
• required for the synthesis, storage, and release
  of the hormone insulin
• regulates thyroid hormone function
• influences behaviour and learning performance
• plays important role in protein synthesis
• participates in carbohydrate, fatty acids and
  alcohol metabolism
• others sperm production, fetal development, taste

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Zinc Absorption Metabolism

• absorption rate varies between 15 - 35
• dependant on zinc status
• absorption inhibited by fibers and phytates
• after absorption may be stored by the protein
  metallothionein
• transported in the blood by several proteins
  including
• albumin
• alpha2-macroglobulin
• transferrin

64
Zinc

• Interactions
• an excess of dietary iron may reduce zinc
  absorption
• a dietary iron zinc ratio gt 2 1 decreases
  zinc absorption
• large doses of zinc
• inhibit iron absorption
• interferes with copper absorption

65
Zinc Sources

• richest sources are protein rich foods

Examples oysters 3 oz gt 12 mg crab 3 oz 4.5
mg lean ground beef 3 oz 4 mg yogurt 1 cup 2
mg Recommendations Men 11 mg/day Women 8
mg/day
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Zinc Deficiency

• most vulnerable pregnant women, young children,
  the elderly, poor
• may result from other disease conditions that
  affect absorption or excretion
• Symptoms
• extreme deficiency leads to severe growth
  retardation and arrested sexual development
  during growth dwarfism

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Zinc Deficiency cont.

• Symptoms cont.
• impaired immune function
• altered taste perception
• diarrhea
• symptoms of a Vitamin A deficiency
• impaired thyroid function
• anorexia
• impaired glucose tolerance
• slowed wound healing

68
Zinc Toxicity

• toxicity from a high dietary intake is rare
• acute excessive doses may result in nausea,
  vomiting, abdominal cramps, diarrhea, headaches
• may interfere with iron and copper absorption and
  metabolism
• chronic elevated intake may depress immune
  function in elderly individuals

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Selenium

• Functions
• forms part of the enzyme glutathione peroxidase
• an antioxidant
• important for protection from OFR
• important for thyroid hormone function
• Food Sources
• protein rich foods such as tuna, lobster, pork,
  eggs, also grains such as oatmeal, whole wheat
  bread, brown rice and others

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Selenium

• Deficiency
• associated with a predisposition to a type of
  heart disease called Keshan disease
• Toxicity
• chronic high doses lead to brittle hair and nails
• high doses produce vomiting, diarrhea, hair loss,
  skin lesions and neurological problems

72
Iodine

• iodine in foods is converted to its ionic form
  iodide by the body
• Functions
• an integral part of thyroid hormone
• thyroid hormone has many important functions
  including
• regulation of basal metabolic rate
• regulation of body temperature
• necessary for reproduction and growth

73
Iodine Sources

• iodized salt, ocean fish, plants grown in iodine
  rich soil, milk
• average intake of North Americans is above
  recommendation but below toxic levels

74
Iodine Deficiency

• results in hypothyroidism
• causes enlargement of the thyroid gland called a
  goiter
• maternal iodine deficiency during pregnancy leads
  to cretinism in the developing fetus

75
Iodine Toxicity

• also enlarges the thyroid gland causing a goiter
• poses risk of suffocation for a fetus if excess
  consumed during pregnancy
• goiter may block airways
• upper limit is 1000 mg per day
• Note
• a goiter may also develop from excess consumption
  of goitrogens, an anti-thyroid substance found in
  plants of the cabbage family

76
Copper

• Functions
• forms part of several enzymes
• e.g. superoxide dismutase, which functions as an
  antioxidant enzyme
• important for the synthesis of hemoglobin
• Sources
• legumes, whole grains, nuts, shellfish, organ
  meats, seeds, water

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Copper

• Deficiency
• rare, may be associated with excess Vitamin C or
  zinc which interfere with absorption
• symptoms include microcytic anemia
• in animals leads to increased blood cholesterol
  and damage to blood vessels
• Toxicity
• rare, may interfere with iron and zinc metabolism

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Fluoride

• Functions
• forms fluorapatite crystals in teeth
• replaces the hydroxyl (OH-) in hydroxyapatite
  crystals
• Deficiency
• associated with dental decay
• 1 part fluoride to 1 million parts water best
  protection
• primary source of fluoride is drinking water
  also in tea and seafood

79
Fluoride

• Toxicity
• fluorosis damage to teeth that pits and stains
  the enamel
• also leads to nausea, vomiting, diarrhea, chest
  pain, and itching

80
Chromium

• Functions
• regulates carbohydrate lipid metabolism
• enhances insulin activity
• Sources
• present in a wide variety of foods (e.g. liver,
  brewers yeast, whole grains, nuts and seeds)
• Deficiency
• produces a diabetes-like condition marked by an
  inability to use glucose normally