Download Water and Major Minerals and Trace Minerals

Water and The Major Minerals
Water
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50-70% of body weight (10 gallons or 40 liters)
Lean muscle contains 73% water
Adipose is about 20%
Survive only few days without water
Polar compound with two partial positive hydrogen molecules and one partial negative
oxygen molecule
Polarity give water the property to dissolve many substances
Water in the Body
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Intracellular fluid - fluid contained within a cell
Extracellular fluid – fluid present outside the cell
Intravascular fliud – fluid within the blood stream
Interstitial fluid – fluid in between cells
Water shifts freely in and out of cells
Osmosis – the movement of water through a membrane from an area of lesser
concentration to a greater concentration
Osmolality – a measure of total concentration of a solution
Osmotic pressure – the exerted pressure needed to keep particles in solution from
drawing liquid toward them across a semi-permiable membrane
Shifts in water influenced by concentration of ions (anions and cations) inside and
outside of cells
Functions of Water
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Serves as a solvent and helps to form a solution
Regulates temperatures because of its high heat capacity (specific heat)
Helps remove wastes (ex: 1-2 liters of urine per day)
Helps form lubricants found in knees and other joints
Water volume directly involved in the regulation Blood and Blood Pressure!
It is basis for saliva, bile, and amniotic fluid
Water Needs
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Need 1ml of water per kcal expended
Consume about 1 liter a day (in various forms of liquids)
Foods provide another liter of water
Water as a by-product of metabolism provides 350 ml of additional water
Therefore water supplies around 2400 milliliters per day for a 2400 kcal diet
Of the 2400, 1400 are used to produce urine
Insensible losses of water - the lungs (400ml), feces (150 ml), and skin (500 ml)
Water Deficiency:
 Thirst – mechanism occurs but imperfect indicator of how much water is really
needed
 Water loss is common in athletes infants , elderly, sickness
 Regulation of water
 Hormones compensate for imperfect thirst mechanism
 Antidiuretic hormone (ADH) - synthesized in hypothalamus,
stored in and released by pituitary; causes reabsorption of water in
kidney
 Renin-Angiotensin mechanism
 If blood volume decreases, the enzyme renin (produced in
kindey)
 Renin then cleaves angiotensinogen (produced by liver)
into angiotensin I
 Angiotensin I is then converted (via an enzyme called ACE
made in lungs) into Angiotensin II
 Angiotensin II then causes 1) vasoconstriction of blood
vessels, 2) release of Aldosterone, and 3) release of ADH
 Aldosterone - hormone that prevents the loss of sodium in the
kidneys, thus decreasing the loss of water
Water in foods – fruits and veggies
Water safety
o Monitored by EPA
o Cryptosporidium
Water toxicity
o Water intake without sufficient electrolyte intake
o Many liters beyond need (hyperhydration)
o May cause death
Minerals
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Major (requiring 100mg or more/day) and trace mineral
Many minerals have similar molecular weights and charges
 Causes competition for absorption
 Affects bioavailability
Bioavailability also affected by non mineral substances
 Fiber
 Oxalic acid
Minerals are primarily excreted though urine
Functions
 Cofactors
 Components of body compounds
 Transmission of nerve impulses
 Body growth
 Water balance
Food sources – plant and animal sources
Risk of mineral deficiencies in North Americans – calcium for major and zinc and iron
for trace minerals
Sodium (Na)
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Sodium found in sodium chloride (NaCl) – 40% sodium 60% chloride
95% sodium is absorbed in the small intestine
Transported in blood stream
Excreted via the kidneys when in excess
 Regulated by rennin-angiotensin and catecholamines
10% of sodium consumed is needed by the body
The rest is eliminated via kidneys, skin, and GI tract
Functions:
 Positive cation of extracellular fluid therefore helps maintain fluid balance
 Involved in nerve transmission
Deficiency (or depletion): causes muscle cramps, nausea, vomiting, dizziness, and shock
Sources: table salt and processed foods
RDA: 500 mg
Toxicity: causes hypertension and calcium loss
Potassium (K)
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90% of potassium absorbed in the small intestine
Transported in the blood stream
Excreted via kidneys
Levels in the body regulated by kidneys and aldosterone
Functions:
 Positive cation of intracellular fluid therefore helps maintain fluid balance
 Involved in nerve transmission
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Deficiency:
 Caused by use of diuretics
 Irregular heart beat, loss of appetite, muscle cramps
Sources: fresh fruits and vegetables
RDA: 2000 mg
Toxicity: hyperkalemia, slowed heart rate
Chloride (Cl)
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All is absorbed in the small intestine and colon
Excreted through kidneys, skin, and GI tract
Functions:
 Anion of extracellular fluid
 Aids in the production of stomach acid (hydrochloric acid)
Deficiency: convulsions seen in infants
Sources: table salt, seaweed, olives, rye, lettuce, vegetables
RDA: 700-750 mg
Toxicity: linked to hypertension
Calcium (Ca)
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99% of calcium in body is used as a component of bone
represents 40% of all minerals present in the body – 2.5 pounds
25% of calcium is absorbed from the diet
Absorption occurs in the duodenum of small intestine
Absorption requirements:
 A ph below 6 and presence of vitamin D
 Parathyroid hormone
 Presence of glucose and lactose
 Normal intestinal flow
Absorption limiting factors:
 Phytic acid in dietary fiber
 Vitamin D deficiency
 Increased intestinal flow (diarrhea)
Functions:
 Bone and tooth strength
 Parathyroid hormone (PTH) role in bone remolding and repair
 Bone mass
 Blood clotting
 Conversion of prothrombin to thrombin
 Nerve transmission
 Muscle contractions
Deficiency:
 Osteopenia
 Osteoporosis
Sources: dairy products, leafy vegetables, canned fish
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RDA: 1000-1200 mg (1300 ages 9-18)
Toxicity: kidney stones and poor mineral absorption
Phosphorus (P)
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70% of dietary phosphorus absorbed
Vitamin D enhances absorption
Excreted by kidneys
Functions: used in bone (calcium phosphate), used in many compounds (ex: ATP), used
in acid-base balance
Deficiency: bone loss
Sources: dairy products and processed cheese
RDA: 700 mg (1250 ages 9-18)
Toxicity: poor bone mineralization
Magnesium (Mg)
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40-60% of dietary Magnesium absorbed in the small intestine
Vitamin D enhances absorption
Excreted by kidneys but some stored in bone and muscle
Functions: used in enzyme catalyzed reactions, activation of ATP, DNA and RNA
synthesis, prevents heart rhythm abnormalities
Deficiency: rapid heart beat, weakness, muscle spasm, disorientation, nausea and
vomiting
Sources: wheat bran, green vegetables, nuts, chocolate, legumes
RDA: 400-420 mg for men 310-320 mg for women
Toxicity: from use of antacids and laxatives; may cause diarrhea, weakness
Sulfur (S)
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Element used in amino acid synthesis; found in wide variety of foods
No deficiencies, no RDA, no toxicities
Minerals and Hypertension
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How are minerals involved in the regulation of blood pressure and blood volume?
Chapter Objectives
After reading chapter eleven - A student should be able to
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Discuss the various compartments of water in the human body
Describe the various types of movement of water in the human body
List and describe the functions of water
Discuss how water is regulated in the body
Describe the deficiency and toxicity of water
In regards to minerals define the process of bioavailability
Discuss the absorption, transportation, excretion, regulation, functions, sour
U.S. Dietary Reference Intakes
Major
Minerals
SODIUM
Trace
Minerals
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500 mg
RDA
POTASSIUM
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2000 mg
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700-750 mg
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1000-1200 mg
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11 mg/day men and 8
mg/day women
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COPPER
0.9 mg/day (900
ug/day)
SELENIUM
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55 ug/day
700 mg
IODIDE
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150 ug/day
RDA
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MAGNESIUM
RDA
NO DRI
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RDA
RDA
SULFUR
ZINC
RDA
RDA
PHOSPHORUS
8 mg for men and 18
mg for women
RDA
RDA
CALCIUM
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RDA
RDA
CHLORIDE
IRON
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400-420 mg
for men 310320 mg for
women
No dietary
reference
intake set
FLOURIDE
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Intake: 3.8 mg/day
for men and 3.1
mg/day for women
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35 ug/day for men
and 25 ug/day for
women
AI
CHROMIUM
AI
MANGANESE
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2.3 mg/day for men
AI
MOLYBDENUM
and 1.8 mg/day for
women
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45 ug/day
RDA
Trace Minerals
Trace Minerals Overview
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“A daily nutritional need of less than 100 mg”
Understanding of trace mineral metabolism is growing
Actual need for trace minerals is debatable
Difficulties studying trace minerals
 Only minute amounts needed by body
 Sophisticated technology required for research
 Induce deficiency is difficult in studies
 Clinical signs and symptoms may only appear with severe deficiency
 Certain tests not reliable
Nutrient Needs For Trace Minerals
 Many have RDA most have only an Adequate Intake (AI)
 Mineral nutrient needs based on “balance studies”
 Balance study indicates the amount of dietary intake needed to maintain a specific
pool
 Minerals interact with each other which cause complications of trying to
individually set dietary needs
Trace minerals in food
 Minerals in plants directly related to mineral content of soil
 Minerals in animals higher because of the variety of plants and other foods
consumed
Trace Minerals
Iron (Fe)
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Found in every cell and about 5 grams in the entire body
Large difference between men (50mg/kg) and women (40mg/kg)
70% of iron in the body is found in hemoglobin
Factors that influence iron absorption:
 Increased absorption:
 Gastric acid
 Heme iron in food
 Myoglobin and hemoglobin
 High body demand for red blood cells
 Transferin
 Low body stores
 Ferritin
 Hemosiderin
 Meat protein factor (MPF)
 Vitamin C
 Form chelates
 Decreased absorption:
 Phytic acid (in dietary fiber)
 Oxalic acid (in leafy vegetables)
 Polyphenols in tea
 Full body stores
 Excess of other minerals (Zn, Mn, Ca)
 Reduced gastric acid output
 Some antacids
Functions:
 Transport of oxygen in hemoglobin
 Involved in electron transport chain in cell respiration
 Iron in peroxidase enzymes helps break down hydrogen peroxide
 Others: immune function, cognitive development, temperature regulation
Deficiency
 Reduction in red blood cell production – iron deficiency anemia
 Produces fatigue
 Hematocrit levels below 34-37% and blood hemoglobin < 10-11 g/100 ml blood
 Other causes of iron deficiency anemia: hemorrhaging, ulcers, hemorrhoids, and
colon cancer
 Measuring iron status (stores): ferritin (< 12 ng/ml) in the blood
 Progression of iron deficiency: increased free erythrocyte protoporphyrins (FEP)
and microcytic hypochromic anemia
 Treatment of iron deficiency anemia is iron sulfate
Sources: steamed oysters, cooked spinach, cooked kidney beans, sirloin steak, pot roast,
fried beef liver, prune juice
RDA: 8 mg for men and 18 mg for women
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Toxicty:
o >45mg/day
o GI upset
o In patients with hematochromatosis which causes increased iron absorption
Zinc (Zn)
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Foods with phytic acids causes decreased zinc bioavailability
Zinc is absorbed throughout the small intestine
Factors affecting absorption include body’s need for zinc and the composition of the meal
in which zinc is consumed
Zinc is released into the blood stream and bound to proteins (albumin) for transport to
liver which releases zinc into general circulation
Zinc induces production of metallothionein which aids in the homeostatic regulation of
zinc absorption
Functions:
 Zinc is a cofactor of nearly 100 enzymes
 Nucleic acid synthesis and function
 Protein metabolism, wound healing, growth
 Immune function
 Development of sexual organs and mineralization of bone-matrix
 Storage, release, and function of insulin
 Cell membrane structure and function
 Component of superoxide dismutase (prevents oxidative damage to cells)
 Carbonic anhydrase which forms carbonic acid (maintains acid-base balance in
blood)
 Alcohol dehydrogenase (alcohol metabolism)
Deficiency: skin rash, diarrhea, decreased appetite and sense of taste, hair loss, poor
growth and development, poor wound healing
Sources: steamed oysters, sirloin steak, pot roast, lamb chop, canned crab meat, wheat
germ, fried beef liver, roasted turkey, cooked black-eyed peas
RDA: 11 mg/day men and 8 mg/day women
Toxicity: < 40mg/day, can reduce copper absorption, diarrhea, cramps, depressed
immune function
Copper (Cu)
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Copper is primarily absorbed in the stomach and duodenum of small intestine
12-75% of dietary copper is absorbed
Phytates, dietary iber, and high dose supplements of vitamin C, zinc, and iron may
interfere with absorption
Ceruplasmin, albumin, and transcuperin transport copper to liver and kidney then
body tissue
Most copper in body is found in liver, brain, blood, skeletal muscle, and bone
Functions:
 Aids in iron absorption
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Part of enzyme
 involved in collagen and elastin synthesis
 in electron transport chain
 that converts dopamine to norepineprine
 involved in myelin (insulates nerves)
 involved in antioxidant reactions
Deficiency: anemia, low white blood cell count, poor growth
Sources: steamed oysters, steamed lobster, fried beef livers, brazil nuts, brewer’s yeast,
walnuts, sunflower seeds, cooked kidney beans
RDA: 0.9 mg/day (900 ug/day)
Toxicity: >8-10 mg/day, vomiting, nervous system disorders,
Selenium (Se)
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Found in many ionic forms but most selenium is bound to the amino acids methionine
and cysteine
Bioavailability higher than iron and zinc
50-100% of dietary selenium is absorbed
Functions: cofactor for the enzyme glutathione peroxidase which is used in antioxidant
reactions
Deficiencies: muscle pain, muscle weakness, Keshan disease (form of cardiomyopathy)
Sources: canned tuna, sirloin steak, shrimp, cooked egg noodles, roasted ham, roasted
chicken, boiled egg, whole-wheat bread, oatmeal
RDA: 55 ug/day
Toxicity: >400 ug/day, nausea, vomiting, hair loss, weakness, liver disease (cirrhosis)
Iodide (I)
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Deficiency linked to goiter in 1920s
Commonly found in fortified table salt
Absorbed along GI tract and transported as free ions in blood
75% of iodide found in the thyroid and is used in the synthesis of thyroid hormone (T3
ad T4)
Functions: used in the synthesis of thyroxine (T4) which is converted to T3, T3 used in
controlling the rate of cell metabolism
Deficiency: goiter, mental retardation, cretinism
Sources: iodized salt, baked haddock, buttermilk, baked cod, cottage cheese, mozzarella
cheese, shrimp, boiled egg
RDA: 150 ug/day
Toxicity: >1.1 mg/day, inhibition of thyroid hormone synthesis and toxic goiter
development
Fluoride (F)
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80-90% of dietary fluoride absorbed throughout GI tract
transported in free ionic form in blood
50% of iodide absorbed is deposited in calcified tissues, bones, and teeth
Functions: reduces dental caries by
 Reducing acid solubility of the enamel
 Promoting remineralization of enamel lesions
 Increase the deposition of minerals that retard the development of cavities
 Reducing the net rate of transport of minerals from the enamel surface
Deficiency: increased risk of dental caries
Sources: drinking water, tea, seafood, and seaweed
Adequate Intake: 3.8 mg/day for men and 3.1 mg/day for women
Toxicity: >10 mg/day, fluorosis, upset stomach, mottling of teeth, bone pain
Chromium (Cr)
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2-10% of dietary chromium is absorbed
bioavailability hard to asses
Functions: enhances insulin action
Deficiency: high blood glucose
Sources: egg yolks, whole grains, pork, nuts, mushrooms, beer
Adequate Intake: 35 ug/day for men and 25 ug/day for women
Toxicity: only when exposed in industrial settings
Manganese (Mn)
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Functions: Cofactor in enzymes
 Pyruvate carboxylase – involved in carbohydrate metabolism
 Superoxide dismutase – involved in antioxidant reactions
Deficiency: none observed
Sources: nuts, oats, whole grains, beans, tea, leafy vegetables
Adequate Intake: 2.3 mg/day for men and 1.8 mg/day for women
Toxicity: >11 mg/day, psychiatric abnormalities, hyperirritability, violence,
hallucinations, and impaired control of muscles
Molybdenum (Mo)
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High amounts of molybdenum may inhibit copper absorption
Component of enzyme xanthine dehydrogenase which is involved in the formation of
uric acid and mobilization of iron from liver ferritin stores
Deficiency: none observed
Sources: milk, liver, beans, grains, nuts
RDA: 45 ug/day
Toxicity: none observed
Chapter Objectives
After reading chapter twelve - A student should be able to...
1. Discuss the absorption, transportation, excretion, regulation, functions, sources,
deficiencies, toxicities, and AIs/RDAs of all trace minerals