Transcript Chapter Eight: The Vitamins

Chapter Eight: The Vitamins
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Define vitamins and identify their
characteristics
Differentiate between the two classes of
vitamins
Name the fat-soluble vitamins
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Major functions
Deficiency results
Significant food sources of each
Vitamins, cntd.
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Differentiate between active and
precursor forms of Vitamin A
Describe the relationship between
Vitamin and Iron Absorption
Characteristics of Vitamins
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Occur in food in much smaller amounts
No energy contributions—no kcalories
Help and facilitate body processes
Necessary for health but not
CURE--ALLS
Vitamins Defined
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Potent, essential, non-caloric, organic
nutrients
Measured in milligrams or micrograms
Assist enzymes in the release of energy
from the energy nutrients
Fat soluble and Water soluble forms
Bioavailability—quantity provided and
amount absorbed
Fat-Soluble Vitamins
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Vitamins A, D, E, and K
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Stored in Liver and Fatty Tissues
Excess not excreted—can be toxic
Travel in the blood with protein
Not necessary to replenish daily
Vitamin A (Retinol and Beta-Carotene)
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Metabolic Functions--Antioxidant
Vitamin A, cntd.
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Vision—part of the pigment of the eye that
allows eye to adjust to changing light
levels
Health of skin and linings of organs—health
of epithelial cells that secrete mucus
Defense against infection
Toxicity: animal sources and high
dosage supplements
Vitamin A, contd.
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Active vs. Precursor form
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Active form (retinol) found in animal
sources—fat of animals
Precursor form (beta-carotene) found in
deep green and dark yellow fruits and
vegetables—activate only when needed
Deficiency: Night Blindness and
dryness of epithelial cells
Precursor Form of Vitamin A
Vitamin D (Calciferol)
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Not totally essential because the body can
make it from sunlight on the skin
Functions: Makes calcium and phosphorus
available in blood to harden bones (bonemaking and maintenance team)
Deficiencies: Rickets in children and
Osteomalacia mostly in child-bearing women
Osteoporosis—impairs calcium absorption
Sources: Eggs, liver, fish oils, and fortified
milk
Vitamin D Deficiency--Rickets
Vitamin E (Tocopherol)
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Function: Anti-oxidant—defends
against oxidation—especially
polyunsaturated fatty acids
Heart health and protection against
fibrocystic disease
Deficiency: Erythrocite hemolysis—
breaking open of red blood cells
Toxicity: above 800 mg/RDA 8-10 mg
Vitamin E, contd.
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Sources:
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Widespread in foods
Vegetable oils, fruits, vegetables and grains
Vitamin K
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Synthesis is possible in the intestinal tract,
but not sole source of it—not found in sterile
GI tract (newborns)
Antibiotics can interfere with synthesis
Function: necessary for normal blood clotting
Sources: green leafy vegetables, cabbage
family, liver, meats, milk, eggs, cereal and
fruits
Water-Soluble Vitamins
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No accumulation in body tissues from
foods—large doses of supplements can
be toxic
Easily absorbed and excreted in urine
when there is excess
Need good sources daily
Vitamin B Complex
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Coenzymes involved in catabolic and
anabolic reactions in the body
Thiamin(B1), Niacin(B3), Riboflavin(B2),
Pantothenic Acid & Biotin
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Involved in catabolic reactions
Needed for the release of energy from the
energy nutrients
Riboflavin Source
Vitamin B Complex, contd.
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Vitamin B6
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Anabolic reaction—synthesis of nonessential
amino acids
Can minimize heart disease risk
Folate
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Anabolic reaction—new cell synthesis—especially
of nervous system and spinal cord of developing
fetus
Deficiency during pregnancy can lead to spina
bifida—incomplete formation of spinal column
Spina Bifida
Vitamin B Complex, cntd.
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Vitamin B12 (Cyanocobalamin)
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Anabolic reaction—formation of new cells,
especially red blood cells
Deficiency is anemia
Vitamin B Complex, cntd.
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Deficiency diseases
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Thiamin—Beriberi
Niacin--Pellagra
Fortification and Enrichment of staple
foods—especially cereals and grain
products has reduced deficiencies of B
Vitamins
Sources B Complex Vitamins
B Vitamin Complex, cntd.
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Good sources are widespread in foods—
whole foods best sources
Light and heat sensitive—can be lost in
cooking liquid
Folate: Best sources are liver, legumes,
and green leafy vegetables (foliage)
Vitamin B12: Only available in animal
products
Vitamin C (Ascorbic Acid)
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Function: Necessary for the formation of the
protein collagen—protein of connective tissue
(wound healing); also an antioxidant for
water solubles
Deficiency: Scurvy—bleeding gums, pinpoint
hemorrhages, bruising easily, failure of
wounds to heal
RDA: 75 -100 mg
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Increases during pregnancy and lactation
Vitamin C, cntd.
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Stress, infections and smoking increase
needs up to 100 mg
Oral contraceptives increase needs
Sources: Fruits and Vegetable groups
only—especially citrus fruits,
strawberries, and cruciferous vegetables
Sources of Vitamin C
Cruciferous Vegetables
Vitamin Supplements—Are They
Necessary?
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Good diet including a variety of foods
should supply vitamins & minerals
needed
Those who may need them
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Low kcalorie dieters
Depressed appetite—illness, age
Illnesses that impair absorption
Heavy blood losses—menstruation (Iron)
Vitamin Supplements, cntd.
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During pregnancy and lactation—especially
iron and folate
Strict (vegan) vegetarians
Newborn infants
Recovery from infection or surgery
Breast fed infants
Best if prescribed by R.D. or M.D.—
multivitamin usually safe
Phytochemicals
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Found in foods—impart tastes, aromas,
colors, etc.
Act as antioxidants and suppress
diseases
Diets rich in whole grains, legumes,
vegetables and fruits can be protective
against heart disease and cancer
Eat colorful foods—orange, red and
green
Test Questions
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The psychological desire to eat is
referred to as:
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Satiety
Appetite
Hunger
Obesity
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Obese people have much more
lipoprotein lipase activity than lean
people
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True
False
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Which of the following is NOT a fatsoluble vitamin?
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A
E
K
C
D
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Which vitamin is present only in foods
of animal origin?
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Riboflavin
Vitamin B12
Pantothenic acid
The inactive form of Vitamin A