Download Vitamins - Ukiah Adult School

Vitamins
Energy Balance, Vitamins
1. Describe the thermic effect of food.
2. Define calorie and kilocalorie.
3. List the sources of stored energy in the body.
4. Calculate basal metabolic rate.
5. List conditions which affect metabolism.
6. Define a list of key terms.
7. List the general functions of vitamins and the key functions of specific
vitamins.
• 8. Name good sources of specific vitamins.
• 9. Name diseases related to vitamin deficiencies.
• 10. Discuss vitamin supplementation.
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Vitamins
• do not provide energy (calories) but they are needed
for metabolism of energy
• function as coenzymes to activate enzymes
• Essential micronutrients
Vitamins
• Recent discovery
• As knowledge of vitamin functions and
requirements grew, policies were enacted to enrich
and fortify foods
• Fortification and enrichment have virtually
eliminated vitamin deficiencies in the general
American population
• Subject to destruction
Vitamins
• Vital, organic substance, necessary in small
amounts
• Cannot be manufactured by the body
• Functions
– Metabolism
– Antioxidants
– Hormones
– Cell membrane components
– Component of light sensitive rhodopsin molecule
Enrichment and Fortification
• Enrich: to add nutrients back that were lost during
processing, e.g., white flour is enriched with B
vitamins that are lost when the bran and germ layers
are removed
• Fortify: to add nutrients that are not naturally found
in the food, e.g., milk is fortified with vitamin D
Vitamins and solubility
• Vitamins are organic compounds that are soluble in
either water or fat; their solubility determines how
they are absorbed, transported through the blood,
stored, and excreted
Fat-Soluble Vitamins
• Vitamins A, D, E, and K
• Stored in liver and adipose
• Vitamins A and D are toxic when consumed in large
quantities over a long period
• Retinol
• Functions
Vitamin A
– Vision
– Tissue strength and immunity
– Growth
• Requirements
• Food Sources
• Deficiency and toxicity
Vitamin D
• Not really a vitamin
• Prohormone cholecalciferol (calciferol)
• Calciferol and dietary vitamin D are activate in
the liver via hydroxylation
• Functions
• Requirements
• Deficiency and Toxicity
• Food sources
Vitamin E
• Tocopherol: the name of a group of 8 fat
soluble nutrients
• Alpha tocopherol
• Functions
• Deficiency and toxicity
Free Radicals
• Are produced continuously in cells as they burn
oxygen during normal metabolism
• Problem - they oxidize body cells and DNA in their
quest to gain an electron and become stable
• These structurally and functionally damaged cells are
believed to contribute to aging and various health
problems such as cancer, heart disease, and cataracts
Antioxidants and free radicals
• Antioxidants - substances that donate electrons to
free radicals to prevent oxidation
• Antioxidants protect body cells from being oxidized
(destroyed) by free radicals by undergoing oxidization
themselves, which renders free radicals harmless
• Vitamin C, Vitamin E, and beta-carotene are major
antioxidants
Vitamin K
• “Koagulation vitamin”
• Functions: blood clotting and bone
development
• Food Sources
• Deficiency and toxicity
Water-Soluble Vitamins
• B-complex vitamins and Vitamin C
• not generally stored in the body so a daily intake is
necessary
• are considered nontoxic
• adverse side effects, however, can occur from taking
megadoses of certain water-soluble vitamins over a
prolonged period
Vitamin C
• Ascorbic Acid
• Functions
– Connective tissue
– Metabolism
– Antioxidant
• Deficiency and toxicity
• Food sources
Vitamin B1
• Thiamine
• Functions
– Energy extraction from glucose
– Fat synthesis for energy storage
• Deficiency
– Beriberi
• Food sources
B2
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Riboflavin
Constituent of 2 co-enzymes
Deficiency and toxicity
Food sources
B3
• Niacin
• Functions
– Co-enzymes
• Deficiency
– Pellagra
• Toxicity
• Food Sources
B6
• Group of 6 related compounds: pyridoxine,
pyridoxal, pyridoxamine and their phosphate
forms
• Extensively stored in tissues
• Deficiency and toxicity
• Food Sources
Folate
• Folic acid
• Functions
• Deficiency
– Megaloblastic anemia
– Neural tube defects
• Food sources
B12
Deficiency
Pernicious anemia
Sore mouth and tongue
• Cobamamine
• Nutritionally this refers
to all cobalamine
derivitives
Amenorrhea
Neuritis
Nutritional dementia
Pantothenic Acid
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From the Greek pantothen: from every side
Cellular metabolism
Biosynthesis of numerous compounds
Deficiency only found in synthetic diets
No toxicity
Biotin
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Also called Vitamin H
Coenzyme for 5 carboxylase enzymes
Very little is needed
No known deficiency
No known toxicity
Food sources
Vitamins, diet and health
• Although diets rich in fruits and vegetables appear to
be protective against chronic diseases such as heart
disease, cancer, and hypertension, it is not known
what components in them are responsible for the
health benefits
• Antioxidant vitamins in foods are suspected of being
beneficial
Vitamins and supplements: more is not better
• High-dose supplements have not been proven to
prevent disease and may disrupt nutrient balances
• Megadoses: amounts at least ten times greater than the
RDA
• In megadoses vitamins function like drugs, not nutrients
• Long-term safety has not been established
• Some reports indicate that single-nutrient supplements
may actually increase, not decrease, health risks
Vitamins and special needs populations
• It is recommended that women who are capable of
becoming pregnant consume 400 micrograms of folic
acid through supplements or fortified food daily
• People over the age of 50 are urged to consume
most of their B12 requirement from supplements or
fortified food
• Vegans need supplemental B12 and D, if exposure to
sunshine is inadequate
Vitamins and limited diets
• Multivitamin supplements provide a limited
safeguard when food choices are less than
optimal
• Other groups who may benefit from taking a
daily multivitamin are the e lde rly, die te rs , finicky
e ate rs , and alcoholics
Facts about fruit and vegetable intake among
Americans
• When French fries and potato chips are excluded,
Americans eat only about 3.6 servings of fruits and
vegetables daily
• 9 out of 10 teenage girls do not eat five servings of
fruit and vegetables daily
• Fruit and vegetable intake is declining--romaine
lettuce and bag lettuce are the only vegetables
Americans are eating more of.
• Obesity levels are lowest for people who eat the
most fruit and vegetables