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Chapter 7
Learning Objectives
Explain the roles vitamins play in growth and good
List and describe the general functions and food
sources of fat-soluble vitamins and water-soluble
List nutrients of concern that many Americans lack in
their diets and foods sources of these nutrients
Learning Objectives
Identify diseases caused by specific vitamin
Give tips to ensure that vitamin intake is sufficient
Identify cooking techniques that promote retention
of nutrients and those that cause nutrient loss from
Essential for life and
Needs are small
 measured
in milligrams
(1/1000 of a gram) or
micrograms (1/1000
of a milligram)
Do not provide energy
Must be obtained
through food
All are organic compounds (contain carbon in their
Each vitamin has specific biological functions
Absence of each vitamin causes a specific deficiency
13 are essential nutrients
 Must
come from food, not made in the body or
the body does not make enough
 Some
foods contain precursors that can be
converted in the body into vitamins
How the Body Uses Vitamins
Facilitate the processes by which other nutrients are:
 Digested
 Absorbed
 Metabolized
 Built
into body structures
Absence of a vitamin may cause a nutrient deficiency
(symptoms go away when vitamins are replenished
through diet)
Dangers of Excess Vitamins
Regular intake of high-dose supplements can be
dangerous, stressing liver and kidney
 Amounts
found in foods are safe
Fat-soluble vitamins are stored, toxicity possible
Supplements can interfere with meds/ alter lab tests
Two Types of Vitamins
1.) Fat Soluble
A, D, E, K
2.) Water Soluble
B vitamins -thiamin, riboflavin, niacin, folate, B12,
B6, Biotin, Pantothenic Acid
Vitamin C
Shortfall Nutrients – or Nutrients of Concern
Many people do not get adequate amounts of:
Vitamin A
Vitamin C
Vitamin D*
Vitamin E
Vitamin K * Biggest nutrient gaps
Potassium *
Most diets also lacking dietary fiber
Most children and adults get too much sodium
Fat Soluble Vitamins
Must be absorbed with fat
Stored in body fat and liver
Can build up to toxic levels, especially as
supplements in high doses
Vitamins A, D, E, K
Vitamin A
Important roles in:
Bone and tooth growth
Cell functions
Immune system
Vitamin A
Retinol – active form
 liver,
egg yolks, dairy foods
Precursors include carotenoids – beta-carotene
which can be changed to active form in intestine
 bright
orange, yellow, green fruits and vegetables
Measured in retinol activity equivalents (RE)
 it
takes 12 mcg of beta-carotene to convert to 1 mcg retinol
Vitamin D
Some made in body with sunlight
Those who do not have skin exposed to sunlight need more
from diet
Acts like a hormone to help body absorb and regulate
calcium and phosphorus for strong bones, teeth and
Several forms:
 Calciferol
 D2
= ergocalciferol
 D3 = cholecalciferol
Vitamin D
Food sources
dairy and other fortified foods, egg yolks
butter, salmon, shrimp, mushrooms
100 IU in 1 cup milk
 fragile bones (osteoporosis)
soft bones (osteomalacia),
 increased cancer risk
depression, dementia
infections, gum disease
Vitamin D Requirements
Dietary Guidelines 2010
 600
IU children, most adults
 800 IU 70 and older
 1000 IU common supplementation recommendation
Up to 10,000 IU recommended to replenish for 1-2
weeks, then 1000 IU a day
Vitamin E - Tocopherol
Antioxidant in cell membranes
 especially lungs, brain, blood
Seeds, nuts, oils
fortified cereals, spinach
greens, pumpkin,
red bell peppers
Vitamin K - Phylloquinone
Intestines make about half of daily need
Needed to make the proteins involved in blood clotting
Antibiotics reduce production
People who take meds to reduce blood clotting may need to adjust
intake of foods with vitamin K
Works with vitamin D to regulate blood calcium levels and
form bone
Food sources: green leafy veg (kale, greens, spinach, broccoli)
Water Soluble Vitamins
Should be eaten daily
None or little stored
Excesses usually excreted through urine
Excess by supplements can cause increased
The B Vitamins
B Vitamins- General Functions
Metabolize Energy as Coenzymes(catalysts)
 release
calories from carbohydrates, protein and fats
Necessary to form red blood cells, heal wounds
Growth and development
Nerve functions
Proper digestion and appetite
B Vitamins Continued..
B vitamins found in most protein foods, leafy green
vegetables and grain (enriched) products
Enrichment- replaces thiamin, riboflavin, niacin
Generally little stored in the body
Oversupply or deficiency of one B vitamin can
effect need and use of others
Thiamin- B1
Critical role in energy
Necessary for nerve
and heart function
Riboflavin- B2
Essential for metabolism of
carbohydrates to produce
Milk, dairy and organ
meats are rich in riboflavin.
destroys riboflavin.
Dairy should be in containers
that block light
Niacin- B3
Essential for metabolism of
carbohydrates to produce
Body can make niacin by
converting tryptophan
(essential amino acid)
Niacin- high doses can
cause itching, flushing,
liver damage, high blood
Pantothenic Acid- B5
Coenzyme in metabolic processes
Deficiencies Uncommon
No toxicities reported
Pyridoxine- B6
Part of coenzyme necessary for metabolism of
carbohydrates, fat and protein
Necessary for nervous and immune system
Needed to convert tryptophan to niacin
Needed to make hemoglobin
Vitamin B12
Assists in bone-blood cell formation
 Pernicious anemia
Protects nerve fibers
Carbohydrate, protein, fat energy
Needs intrinsic factor for absorption
Found in animal foods, fortified in
Vegans should B12 supplement
Part of coenzymes
necessary to form DNA
Important for red blood
cell formation
Helps the body use
 Food
Sources: legumes, oranges, green leafy
vegetables, enriched grains, asparagus, beets
 Some
lost in cooking
 Fortification-
adds folacin to grain foods.
 Folacin- more stable form
Critical in early pregnancy to prevent birth defects
 Part of coenzymes necessary to form DNA
 Women of child bearing age need supplemented
Vitamin C – Functions
Helps make collagen (protein that stabilizes cell walls)
Helps keep gums and other tissues healthy
Aids in the healing of cuts and wounds
Helps the body absorb iron
Necessary to form thyroxin (hormone that regulates
metabolic rate)
Vitamin C
Shortfall nutrient because many Americans do not
eat enough fruits and vegetables
More needed by:
 Pregnant and lactating women
 Smokers
 Infections, fevers or wound healing
Food Issues Related to Vitamin C
Least stable nutrient. Destroyed by:
 Heat
 Leaching
into water while cooking
 Evaporation
Some juices and cereals fortified with Vitamin C
Supplements in high doses may cause gastrointestinal
Vitamin C - Sources
Excellent sources include:
 Red bell peppers
 Oranges
 Grapefruit
 Broccoli
 Strawberries
 Papaya
 Brussels sprouts
 Fortified cereal or juices
 Tomatoes
Bioavailability is Influenced By:
Nutritional status - if you are deficient your body
will absorb more
Other nutrients at the same meal- compete for
protein carriers needed for absorption
Nutrients in high dose supplements are not used as
well as nutrients in foods
Binders such as oxylates and phytates
Nutrient Bioavailability
Enhanced By:
The form of a nutrient;
vitamin D3 is absorbed better than D2
Fermentation processes
Ex. miso and tempeh, may improve iron bioavailability
Food preparation techniques
soaking and sprouting beans, grains and seeds, leavening
bread, can reduce binding of zinc by phytic acid and
increase zinc bioavailability
Organic acids
Ex. citric acid can enhance zinc absorption
Nutrient Bioavailability is Reduced By:
Too much of one mineral can reduce the
absorption of another
Polyphenols in regular and herbal teas, coffee and
red wine bind some iron
Cooking softens cell walls of food so more nutrients
Nutrient Retention – Purchase Forms
Canned: Canned foods are packed at their peak of
freshness and due to the absence of oxygen during
their storage period, canned fruits and vegetables
have a longer shelf life and remain relatively stable
up until opened.
Fresh: Fresh is best if consumed within a short time
after purchasing.
Frozen: Frozen products are packed at their peak of
nutrition and freshness. At least equal to fresh in
Nutrient Retention – In the Kitchen
To retain nutrients: keep fresh produce chilled and
Peel only when necessary. Peeling removes nutrients
and fiber of peel and under peel
Use pulp in citrus rather than straining it out
Purees and coulis increase nutrient availability by
breaking cell walls
Serve cooked vegetables immediately after
cooking – holding causes nutrient losses
Nutrient Retention – In the Kitchen
Reserve liquids from cooked vegetables and add to
stocks, sauces, etc
Fry as little as possible. High heat destroys some
nutrients and creates free-radicals
Drain and rinse canned beans to reduce sodium
Drain brines from capers, pickles and other foods
packed in salted liquids
Chapter 7: Vitamins, Minerals and
Questions and Answers