Minerals: Key Concepts

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Minerals Key Concepts

• Minerals are single atoms that cannot be created
  or destroyed by any ordinary means
• These single atoms usually carry a charge, which
  makes them reactive
• Minerals are components of body structures and
  play key roles in the regulation of body
  processes

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Mineral Charges

• Charge allows minerals to combine with minerals
  of opposite charge to form stable compounds
• These become part of bones, teeth, cartilage, and
  other tissues
• In body fluids, charged minerals are a source of
  electrical power to stimulate muscles to contract
  and nerves to react
• Charge of minerals is related to many other
  functions
• helps maintain an adequate amount of water in the
  body
• assists in neutralizing body fluids when too
  acidic or basic
• minerals are components of proteins and enzymes

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Charge Problems

• Minerals may combine with other substances in
  food and form highly stable compounds not easily
  absorbed
• Much of the calcium in spinach is bound to oxalic
  acid
• Zinc in whole-grain products is poorly absorbed
  because it is bound tightly to phytate
• Absorption of iron decreases by about 50 if tea
  or cola is consumed
• Iron binds with tannic acid in tea and colas

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CALCIUM AND VITAMIN D
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Calcium

• Calcium in the diet is absorbed with the help of
  Vitamin D either in the blood or in food
• 99 of the 3 lbs of calcium in the body is
  located in bones and teeth
• 1 is found in blood and other body fluids, where
  it has many important roles
• Calciums noted function is in bone formation and
  osteoporosis prevention

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Bones

• 206 bones in our body are slightly flexible
  living tissues infiltrated by blood vessels,
  nerves, and cells
• Solid parts are networks of protein fibers
  embedded with mineral crystals
• Calcium is abundant in bone, along with magnesium
  and other minerals
• Teeth are like bone plus covering called enamel
• Enamel protects teeth from acids and wear

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Bone Formation

• Bones develop and mineralize throughout the first
  3 decades of life
• Every day, cells called osteoclasts break bone
  down
• Cells called osteoblasts repair damage by forming
  new, healthy bone.
• Called remodeling

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Inadequate calcium - Bangladesh
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Treating Rickets
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Building Strong Bones

• Adequate calcium and vitamin D
• Regular exercise, especially weight-bearing and
  muscle strengthening exercise.
• Adequate vitamin K, found in green, leafy
  vegetables
• Not excessive preformed vitamin A
• Beta-carotene is not a factor

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Whats the RDA and how to get it

• Calcium

• Vitamin D

• 1,000 milligrams/day for those age 19 to 50

• a multivitamin that supplies 800 to 1,000 IU of
  vitamin D per day

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Sources of Calcium

• Dairy
• All but butter

• Non Dairy
• Soy beverages
• Fortified with calcium
• Tofu
• Fish with bones
• i.e. sardines
• Dark greens
• Legumes

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Remodeling Bones

• During remodeling, old protein matrix is replaced
  and remineralized
• Total bone replacement every 10 years
• Up to about age 30, osteoblasts build more bone
  than is lost
• Peak bone density reached by age 30

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Bone Remodeling

• After that, bone mineral content no longer
  increases
• The higher the peak bone mass, the less likely it
  is that osteoporosis will develop
• After age 50, blood levels of estrogen and
  testosterone decrease
• Bones demineralize as osteoclasts outperform
  osteoblasts
• Insufficient calcium is one cause of

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Osteoporosis

• Over 20 million adults in the United States have
  osteoporosis
• About half of all women and about one third of
  men will have an osteoporotic fracture during
  their lives

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Osteoporosis

• 1.5 million suffer broken bones each year due to
  the disease
• 300,000 hip fractures/year with a 20 death rate
  within one year
• Many permanent disabilities

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Causes of Osteoporosis

• Related to genetics, race, sex, diet, exercise,
  childbearing
• Develops later in
• African Americans
• Men
• Women who have had several children
• Typically, by the time a woman is 70 her bones
  are 30 to 40 less dense

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Early Osteoporosis

• Whos at most risk?
• Asians and Caucasians
• Women, especially childless
• Small-boned, thin people
• Smokers
• Sedentary people
• And, of course, those with poor diet

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Build and Maintain Bones

• Vitamin D increases calcium absorption and the
  deposition of calcium into bone
• Our need may be met by vitamin D-fortified milk
  and breakfast cereals or exposing the skin to the
  sun
• In much of the world, exposing hands and face to
  sunshine for 5 to 30 minutes produces a days
  supply of vitamin D

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Build and Maintain Bones

• After 50, preserving bone density requires
  adequate calcium and vitamin D
• Regular exercise, especially weight-bearing and
  muscle strengthening exercise.
• Adequate vitamin K
• RDA for women is 90 mcg
• Data from Nurses Health Study suggests that over
  110 mcg is better for bone health

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Prevent Osteoporosis

• Avoid excessive preformed vitamin A
• Retinol
• May increase number of osteoclasts
• Caffeine may increase calcium loss in urine
• Phosphoric acid (in cola) may increase calcium
  loss also
• High protein diet may increase calcium loss

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Too Little Calcium

• Only 14 of females and 36 of males between 12
  and 19 consume recommended calcium
• Low calcium intake during growing years increases
  probability of fractures and osteoporosis
• Americans dont drink milk like we used to-
• Will osteoporosis increase for coming generations?

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Osteoporosis Treatment

• Calcium supplements or intakes to 1000-1500
  milligrams per day
• Vitamin D supplements (800 IU or more)
• Other medications (phosphomax, etc)
• Weight-bearing exercise (walking, tennis)
  stimulates bone growth and decreases progression
  of osteoporosis

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Where do You get your Calcium?

• To meet recommended level of intake choose 2 or 3
  foods rich in calcium every day
• Calcium absorption decreases with age
• and Vitamin D inadequacy

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Too Much Calcium

• You can consume too much calcium
• Supplement doses exceeding 2.5
• grams (2500 mg) per day produce drowsiness,
  constipation, and cause calcium to deposit in
  tissues

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IRON BASICS
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Charge Problems

• Minerals may combine with other substances in
  food and form highly stable compounds not easily
  absorbed
• Much of the calcium in spinach is bound to oxalic
  acid
• Zinc in whole-grain products is poorly absorbed
  because it is bound tightly to phytate
• Absorption of iron decreases by about 50 if tea
  or cola is consumed
• Iron binds with tannic acid in tea and colas

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Iron

• Most iron is found in hemoglobin
• Hundreds of hemoglobin molecules are in each red
  blood cell
• Blood cells are made in bone marrow
• Small amounts of iron are present in myoglobin in
  other cells

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Iron in Hemoglobin

• Iron readily combines with oxygen
• Iron in hemoglobin attaches to oxygen in the
  lungs
• Hemoglobin releases oxygen from iron to cells
• Free iron picks up carbon dioxide from cells
• Blood returns to lungs, carbon dioxide is
  released
• Free iron combines with oxygen
• The cycle continues

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Hemoglobin Structure

• Four polypeptide strands
• Each has a
• Heme ring, in red, which contains the iron.
• Oxygen is bound and then released by the iron

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Iron in Myoglobin

• Iron in myoglobin traps oxygen, stores it, and
  releases it as needed for energy for muscle
  activity
• Myoglobin boosts oxygen available to muscles
• These functions require supply of iron that is
  sufficient

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Iron Deficiency

• 1/3 of people in world are iron deficient
• Iron deficiency affects mostly children and women
  with high need and low consumption
• Iron deficiency develops in people who have lost
  blood, including women with heavy menses (slow
  bleeding to death)

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Consequences

• People with iron deficiency
• are weak and tired
• have short attention span
• have poor appetite
• are susceptible to infection
• become irritable easily

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Iron-deficiency anemia

• Develops with additional symptoms
• People with iron-deficiency anemia
• look pale
• are easily exhausted
• have rapid heart rates
• Iron-deficiency anemia in infants and young
  children is related to lasting retardation in
  mental development

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Getting Enough Iron

• Sources of iron
• heme in meat, iron in plant foods
• Iron in fortified foods and supplements
• Foods cooked in iron and steel pans
• Enough iron is 8 milligrams for men and 18
  milligrams per day for women
• RDA for women decreases after menopause
• Women have to consume about 2500 calories per day
  of good foods to obtain 15 milligrams of iron

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• Ferrous sulfate (Feosol, Slow Fe)
• Ferrous gluconate (Fergon)
• Ferrous fumarate (Femiron, Feostat)

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Getting Enough Iron

• Most iron in plants and eggs tightly bound
• A three-ounce hamburger and a cup of asparagus
  both contain three milligrams of iron
• 20 times more iron is absorbed from hamburger
  than from the asparagus
• Transferrin in intestinal mucosa regulates iron
  absorption increased by low levels of iron
  stores when iron stores high, less iron absorbed
• Such regulation of iron absorption provides some
  protection against iron deficiency and overdose

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Cross-section of Digestive Tract
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Overdosing on Iron

• Excess iron absorbed into the body cannot be
  easily excreted
• Iron is deposited in the liver, pancreas, and
  heart
• Iron excess results in liver disease, diabetes,
  and heart failure
• People at risk of iron toxicity
• Heavy drinkers (increased absorption of iron)
• Very high iron intake or one time overdose
• Genetic disorder

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Hereditary Hemochromatosis

• Most common genetic disease in whites
• Nonspecific early symptoms
• Fatigue Weakness
• Weight loss Joint Pain
• Abdominal pain
• As Iron Accumulates
• Arthritis Diabetes
• Grey or bronze tone to skin
• Cirrhosis of the liver Liver cancer
• Heart failure

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Frequency Treatment

• North western European ancestry
• 0.5 homozygous, 10 carriers
• Mexican Americans .03 homozygous
• African Americans .06
• Occurrence of symptoms
• Earlier for men than women
• Detection Prevention
• Treatment Phlebotomy

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Overdosing on Iron Supplements

• Can cause rapid tissue damage, seizures, coma
  heart failure
• Victims often young children
• Lethal dose of iron for a two-year-old child is
  about three grams, amount in 25 120 mgm pills
• 40 childrens multivitamins with iron could
  seriously injure a child

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Iron Overdoses, 1990's

• In 1991, 10 children died from iron overdoses.
• Government required warning labels and childproof
  bottles
• 1998 2500 children under 6 overdosed on iron
• 730 required treatment
• 0 deaths
• 1999-2002, only one child death
• Childproof containers and careful parents protect
  children