Transcript The Vitamins - Manasquan Public Schools

The Vitamins
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Vitamins
Organic, essential nutrients required in
minute amounts to perform specific
functions that promote growth,
reproduction, or the maintenance of health
and life
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Bioavailability
The availability of vitamins from food
depends on two factors:
The quantity provided from a
food
The bioavailability of the vitamin
from that food
Bioavailability refers to the rate and
extent to which a nutrient is absorbed.
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Vitamins As Precursors Or
Provitamins
Some vitamins occur in foods in
inactive forms.
Once in the body they are changed
chemically to an active form of the
vitamin.
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Solubility
Apparent in the different food sources
of the vitamins
Affects their absorption, transport,
and excretion by the body
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Water Soluble Versus Fat
Soluble Vitamins
Water Soluble
 Thiamin- B1
 Riboflavin- B2
 Niacin- B3
 Biotin
 Pantothenic Acid
 Vitamin B6
 Folate
 Vitamin B12
 Vitamin C
Fat Soluble
Vitamin A
Vitamin D
Vitamin E
Vitamin K
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Water
Soluble
Fat
Soluble
Absorption
Directly into blood
First into lymph, then
the blood
Transport
Travel freely
May require protein
carriers
Storage
Circulate freely in
water filled body
compartments
Kidneys detect and
remove excess
Possible to reach
toxic level from
supplements
Needed in frequent
doses
Trapped in the cells
associated with fat
Excretion
Toxicity
Requirements
Tend to remain in fat
cells
Likely to reach toxic
level from
supplements
Needed in periodic
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doses
Thiamin- B1
Part of coenzyme thiamin pyrophosphate
(TPP) which assists in energy metabolism
Recommended intake is 1.2 mg/day and
1.1mg/day for adult men and women,
respectively.
Best sources of thiamine are pork, liver,
sunflower seeds, legumes, whole grain
and enriched breads and cereals.
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Thiamine Deficiency
 Prolonged deficiency is known as Beriberi.
 First recognized in East Asia where rice
comprises ~80% of their diet. They began
“polishing” the rice which is removal of the hull.
Rice hulls were the principal source of thiamine.
 Characterized by edema (wet beriberi) or
wasting (dry beriberi), enlarged heart, muscle
weakness, loss of appetite, mental confusion,
paralysis.
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Thiamine Toxicity
None noted
Cannot occur from food sources
May occur with supplementation, however
excess is readily excreted in the urine
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Riboflavin- B2
 Part of coenzyme flavin mononucleotide (FMN) and
flavin adenine dinucleotide (FAD) used in energy
metabolism
 Supports normal vision and skin health
 Recommended intake is 1.3 mg/day and 1.1 mg/day
for adult men and women, respectively.
 Best food sources are milk, yogurt, cottage cheese,
meat, whole grain and enriched breads and cereals.
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Riboflavin Deficiency
Deficiency of riboflavin is referred to as
ariboflavinosis.
Characterized by angular cheilosis,
glossitis, photophobia, and inflamed, scaly
skin lesions
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Riboflavin Toxicity
None noted
Cannot occur from food sources
May occur with supplementation, however
excess is readily excreted in the urine
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Niacin- B3
 Part of the coenzyme nicotinamide adenine
dinucleotide (NAD) used in energy metabolism
 Supports the health of skin, nervous system, and
digestive system
 Recommended intake is 16 mg NE/day and 14 mg
NE/day for adult men and women, respectively.
 Best food sources are milk, eggs, meat, poultry, fish,
whole grain and enriched breads and cereals. 14
Niacin Deficiency
Deficiency of niacin is known as Pellegra.
Characterized by vomiting, diarrhea,
glossitis, fatigue, memory loss, bilateral
symmetrical dermatitis.
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Niacin Toxicity
“Niacin flush”- a burning, tingling, itching
sensation that occurs when a person takes
large doses of nicotinic acid.
Can effectively lower blood cholesterol but such
therapy needs close monitoring because of its
adverse side effects.
Common toxicity symptoms include nausea,
diarrhea, vomiting, peptic ulcers, headache,
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fatigue, low blood pressure, and liver damage.
Biotin
Functions as a coenzyme in the metabolism
of carbohydrates and fats
Biotin is needed in very small amounts.
Instead of an RDA, an Adequate Intake (AI)
has been established at 30 μg/day for both
adult men and women.
Biotin is widespread in foods, however, the
best sources are organ meats, soybeans,
fish, and whole grains.
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Biotin Deficiency
Deficiency is uncommon.
Symptoms include loss of appetite,
nausea, depression, lethargy,
hallucinations, muscle pain, weakness,
fatigue, dry scaly dermatitis, and hair loss.
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Pantothenic Acid
Involved in more than 100 different steps in
the synthesis of lipids, neurotransmitters,
steroid hormones, and hemoglobin
The principal active form is part of
coenzyme A called “CoA”.
CoA is involved in several metabolic
pathways.
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Pantothenic Acid {continued}
An AI for pantothenic acid has been set at
5mg/day to replace daily losses.
Pantothenic acid is widespread in foods,
however the best sources are organ
meats, mushrooms, broccoli, and whole
grains.
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Pantothenic Acid Deficiency
Deficiency is uncommon.
Characterized by nausea, vomiting,
stomach cramps, insomnia, fatigue, and
depression
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Vitamin B6- Pyroxidine
Part of coenzymes important in amino acid
and fatty acid metabolism
Helps convert tryptophan to niacin and
serotonin
Helps make red blood cells
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Vitamin B6- Pyroxidine {continued}
Recommended intake is 1.3 mg/day for
both adult men and women.
Best food sources are green leafy
vegetables, meats, fish, poultry, shellfish,
and legumes.
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Vitamin B6- Pyroxidine
Deficiency
Deficiency is uncommon.
Characterized by small cell type anemia,
glossitis, angular cheilosis, insomnia,
irritability, muscle twitching, convulsions,
scaly dermatitis, and kidney stones.
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Vitamin B6- Pyroxidine
Toxicity
Toxicity is uncommon.
First appeared in 1983 in people taking
greater than two grams per day for two
months or more
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Folate
 Functions as coenzyme used in DNA synthesis and
therefore is important in cell formation
 Folate prevents neural tube defects in the growing
fetus. The brain and spinal cord develop from the
neural tube in the early weeks of gestation.
 Neural tube defect- malformations of the brain, spinal
cord or both during embryonic development.
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Folate {continued}
Recommended intake is 400 μg/day for both
adult men and women.
Best food sources are green leafy
vegetables, legumes, seeds, and liver.
There is growing evidence that folate plays
a role in preventing heart disease by
decreasing homo-cysteine levels. Elevated
homocysteine is associated with increased
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risk of developing heart disease.
Folate Deficiency
Characterized by a large cell type of
anemia, heartburn, diarrhea or
constipation, immune system
suppression, glossitis, mental confusion,
weakness, fatigue, irritability, and
insomnia.
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Vitamin B12
Characterized by the presence of cobalt
The active forms of coenzyme B12 are
methylcobalamin and deoxyadenosylcobalamin.
Works closely with folate, thus also playing a
role in the prevention of heart disease
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Vitamin B12 {continued}
Recommended intake is 2.4 μg/day for
both adult men and women.
Only found in animal products
Best food sources are meat, fish, poultry,
shellfish, milk, cheese, and eggs.
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Vitamin B12 Deficiency
 B12 gets absorbed by attaching to a glygoprotein in
the stomach known as the intrinsic factor (IF).
 Pernicious anemia is due to lack of or ineffective
IF.
 It is characterized by a large cell type anemia and
memory loss.
 A deficiency can also occur from inadequate
dietary intake.
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Vitamin C
collagen synthesis
antioxidant properties
thyroxin synthesis
amino acid metabolism
immune system booster
aides in the absorption of iron
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Vitamin C {continued}
Recommended intakes are 60 mg/day for
both adult men and women, 100 mg/day
for pregnant women and smokers.
Best food sources are citrus fruits, dark
green vegetables, cantaloupe,
strawberries, peppers, and tomatoes.
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Vitamin C Deficiency
Referred to as Scurvy.
Characterized by small cell type anemia,
pinpoint hemorrhages, immune system
suppression, bleeding gums, loose teeth,
muscle pain, joint pain, and poor wound
healing.
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Vitamin C Toxicity
Cannot occur from food sources
May occur with supplementation, however,
excess is readily excreted in the urine
Characterized by nausea, diarrhea,
abdominal cramps, headache, fatigue, and
rashes
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Vitamin A
Three active forms in the body: retinol,
retinal, and retinoic acid, collectively
known as the retinoids.
Promotes vision
Participates in protein synthesis and cell
differentiation
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Vitamin A {continued}
Supports reproduction and growth
Recommended intake is 1000 μg and 800 μg
retinol equivalents (RE) per day for adult men
and women, respectively.
Best food sources of preformed vitamin A are
foods of animal origin such as liver, fish, milk
and milk products, butter, and eggs.
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Vitamin A Deficiency
 Deficiency takes one to two years to develop after
vitamin A intake has been stopped due to the
body’s effective storage of fat soluble vitamins.
 Characterized at first by night blindness, but if left
untreated can cause xeropthalmia or
keratomalacia
 Xeropthalmia- progressive blindness caused by
vitamin A deficiency.
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Vitamin A Deficiency
Keratomalacia- softening of the cornea seen in
severe vitamin A deficiency that leads to
irreversible blindness.
Other symptoms include diarrhea, plugging of
hair follicles with keratin forming white lumps,
immune system suppression and kidney
stones.
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Vitamin A Toxicity
Toxicity can occur when taking greater than ten
times the RDA.
Characterized by joint pain, headaches, dry,
itchy, peeling skin, jaundice, nose bleeds, hair
loss, loss of appetite, insomnia, fatigue, blurred
vision, nausea, and vomiting.
Can cause birth defects in pregnant women .
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Vitamin D
Synthesized in the body with the help of
sunlight
Chief function is the mineralization of bones.
Recommended intake is 5 μg per day for
both adult men and women, respectively.
Best food sources include milk, margarine,
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butter, cereals, veal, beef, and liver.
Vitamin D Deficiency
Deficiency disease known as rickets in
children and osteomalacia in adults.
Rickets- vitamin D deficiency disease seen
in children characterized by inadequate
mineralization of bone manifested in
bowed legs or knock knees.
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Vitamin D Deficiency
Osteomalacia- a bone disease
characterized by softening of the bones.
Symptoms include bending of the spine
and bowing of the legs, occuring most
often in adult women.
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Vitamin D Toxicity
Likely to be toxic when consumed in
amounts above the recommendations
Characterized by nausea, vomiting,
increased blood calcium and phosphorus,
loss of appetite, headache, muscle
weakness, joint pain, excessive thirst, and
irreversible kidney damage
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Vitamin E
One of the body’s primary antioxidants
Evidence suggests that vitamin E can reduce
the risk of heart disease.
Recommended intake is 10 mg α TE and 8 mg
α TE per day for adult men and women,
respectively.
Best food sources are wheat germ oil, soybean
oil, corn oil, and sunflower seeds.
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Vitamin E Deficiency
Deficiency is rare but may be encountered
in cases of fat malabsorption.
Characterized by a hemolytic anemia
Prolonged deficiency can cause
neuromuscular dysfunction, impaired
vision and speech
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Vitamin E Toxicity
Toxicity is rare.
Can occur with supplementation
May interfere with the blood clotting action
of vitamin K
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Vitamin K
Primary function is the synthesis of blood
clotting proteins
Participates in the synthesis of bone
proteins
Can be obtained from non food sources
such as the bacteria in the GI, however,
that can only meet 1/2 of a person’s needs.
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Vitamin K {continued}
Recommended intakes are 80 μg and 65
μg per day for adult men and women,
respectively.
Best food sources are liver, leafy green
vegetables, and cabbage like vegetables.
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Vitamin K Deficiency
Deficiency is rare but it may be encountered
in cases of fat malabsorption, which would
diminsh vitamin K absorption.
Antibiotics kill the vitamin K producing
bacteria in the intestine.
Deficiency would be characterized by
hemorrhaging.
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Vitamin K Toxicity
Toxicity is rare.
Can occur with supplementation
High dietary intakes of foods rich in vitamin
K may interfere with anticoagulating
medications.
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Antioxidants
A compound that protects others from oxidation
by being oxidized itself. An antioxidant donates
electrons to another substance, that substance
becomes reduced as the antioxidant
simultaneously becomes oxidized.
“Free radical scavengers”
Free Radicals- atoms and molecules that have
one or more unpaired electrons resulting in the
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high reactivity of free radicals.
Antioxidants
Research has linked antioxidants as
defenders against certain types of cancers
and heart disease.
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