Fat
Soluble
Vitamins
By Jennifer Turley and Joan Thompson
© 2013 Cengage
Presentation Overview
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Comparison of vitamins in the body.
Diagnosing deficiency and toxicity.
The fat soluble vitamins, A, D, E, K.
Notable health implications.
Vitamin A
Vitamin E
Vitamin D
Vitamin K
Chemical Forms. Intake Need. Functions. Deficiency. Toxicity. Food Sources.
Vitamin A
Vitamin D
Vitamin E
Vitamin K
Comparison of
Vitamins in the Body
Water Soluble:
absorbed into blood
stream directly, circulate,
travel, and stored in
water
compartments, excrete
in urine, without intake
deficiency signs and
symptoms occur more
quickly, toxicity is
possible though shorter
lived when intake is
normalized.
Fat Soluble: absorbed into lymph, many require protein carriers, associate with
fat, not readily excreted, without intake deficiency signs and symptoms occur more
slowly, toxicity is possible and longer lived even when intake is normalized.
Diagnosing Nutritional Deficiency
or Toxicity
1.
2.
3.
4.
Dietary records: Demonstrate low/high intake and/or
confirm a metabolic or physiological problem that
creates an altered need.
Clinical deficiency or toxicity symptoms: Are
compatible with low/high dietary intake or altered
need.
Biochemical tests: Such as blood levels, tissue
levels & urine levels demonstrate low/high body
levels of the nutrient.
Nutrient supplementation: Serves as biological
evidence by correcting the deficiency signs &
symptoms. For toxicity, removal of the excess.
The Fat
Soluble
Vitamins
Vitamin A Chemistry
• A family of compounds including:
– Retinol, Retinal, Retinoic acid
– Pro-Vitamin A carotenoids like beta-carotene
Retinyl Esters
(animal foods)
Retinol
(reproduction)
Beta-Carotene
(plant foods)
Retinal
(vision)
Retinoic Acid
(Growth Regulator)
Vitamin A Functions
• Vision
• Internal & external
surface linings
(epithelial cells)
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Growth
Reproduction
Embryonic development
Gene expression
Immune function
Provitamin A forms
have antioxidant
properties
Vitamin A
Deficiency vs Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
Approx. <500 µg RE/day
DRI: 700-900 µg RE/day
(>UL)
>3,000 µg RE/day
Hypovitaminosis A
Bone & tooth: Impaired
growth
Central Nervous System:
Night blindness, complete
blindness (Xerophthalmia)
GI System: Diarrhea
Immunity: Depressed
immunity, more
infections
Skin: Hyperkeratosis
(thickened skin)
RDI: 5,000 IU
Normal vision, gene
expression, reproduction,
embryonic development,
epithelial cell
maintenance, growth, and
immune function
25 mg betacarotene (provitamin A is safe
to take daily if you
are not a smoker
or drinker).
Bone & tooth: Decreased
bone mineral density
Central Nervous System:
Headache, vertigo
GI System: Nausea and
vomiting, liver
abnormalities
Neuro-Muscular:
Incoordination
Skin: orange color with
excess beta-carotene
Other: Retinoid
embryopathy
Adult deficient, adequate, toxic values
Vitamin A: Food Sources
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Retinol: (animal)
Fortified milk, cheese, butter, margarine
Eggs
Liver
Beta-Carotene: (Plant)
dark green leafy vegetables
broccoli, deep orange fruits, & vegetables
Vitamin A in Foods
Adult DRI: 700-900 µg
RE/day
Vitamin D Chemistry
Synthesis & Functions
REGULATES
Ca-P Balance
• Increases bone
mineralization
• Increases intestinal
absorption of
calcium
• Increase phosphorus
excretion
Antiproliferative
Prodifferentiation
Vitamin D
Deficiency vs Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
Approx. <3 µg/day
DRI: 15 µg/day
(>UL)
>50 µg/day
Rickets (children)
Osteomalacia (adults)
Bone & tooth: poor growth,
bowed legs, soft bones,
pigeon chest, knocked knees,
and malformed teeth in
children. Porous bones in
adults.
Cardio-Vascular:
increased circulating levels
(PTH) and (AlkP) and
decreased circulating levels of
serum phosphorus
GI System: Decreased
calcium absorption
RDI: 400 IU = 6.5 µg
Normal calcium
and
phosphorus
balance and
cell metabolism
Needs are based
upon an inadequate
exposure to
sunlight.
Sunlight not
implicated in
toxicity.
Hypervitaminosis D
characterized by high
levels of 25(OH)D from
supplementation
Cardio-Vascular: High
blood calcium
Central Nervous
System: Weakness
GI System: Nausea,
vomiting, anorexia
Other: Kidney stones,
increased thirst,
urination, and urinary
calcium
Adult deficient, adequate, toxic values
Vitamin D: Sources
• Fortified products like milk,
margarine, & some cereals
• Eggs & fatty fish
• Self-synthesis with unprotected
peak sunlight exposure
Vitamin D in Foods
Adult DRI: 15 µg/day
Vitamin E Chemistry
• A family of alpha, beta, gamma, delta
tocopherols & tocotrienols.
• Alpha-tocopherol is believed to be the
most active form.
Vitamin E Functions
And at the
molecular level
Vitamin E
Deficiency vs Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
Approx. <10 mg/day
DRI: 15 mg/day
(>UL)
>1,000 mg/day
Premature
infants:
hemolytic
anemia
Adults: not well
characterized
RDI: 30 IU
Normal cell
membrane
integrity, reduced
oxidative stress,
and molecular
functioning
Relatively nontoxic
Toxicity with
supplements
Interferes with
vitamin K’s role in
blood clotting,
augmentation of
anti-blood clotting
medication and
increases hemolysis
Adult deficient, adequate, toxic values
Vitamin E: Food Sources
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Nuts
Seeds
Plant oils
Wheat germ
Fortified cereals
Vegetables
Vitamin E in Foods
Adult DRI: 15 mg/day
Vitamin K Chemistry
• Phylloquinone (K1) from plant sources &
naphthaquinones (K2, multiple forms)
from animal sources & gut bacteria.
Vitamin K
Deficiency vs Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
Approx. <60 µg/day
DRI: 90-120 µg /day
RDI: 90 µg
(>UL)
Not Determined
Cardio-Vascular:
Increases
clotting time,
hemorrhaging
with cut or injury
Normal blood Poorly described in adults
clotting & bone GI System: High levels
from supplemented
metabolism
menadione causes
jaundice and liver
damage in infants
Cardio-Vascular:
Interference with antiblood clotting medication
Adult deficient, adequate, toxic values
Vitamin K: Sources
• Green leafy & cruciferous
vegetables
• Soybeans
• Some plant oils
Vitamin K is made by
bacteria in the
gastrointestinal tract
Vitamin K in Foods
Adult DRI: 90-120 µg/day
Summary
• Diagnosing & confirming a nutrient deficiency or toxicity
requires a diet analysis, clinical evaluation, biochemical
analysis, & evaluating the response to corrected intake levels.
• Toxicities and deficiencies take longer to develop for fat
soluble vitamins as compared to water soluble vitamins.
• The fat soluble vitamins are grouped by their solubility in oil.
• The fat soluble vitamins have specific chemical forms &
functions in the body.
• DRIs exist for essential fat soluble vitamins: A, D, E, & K.
• Deficiency & toxicity signs & symptoms are unique for each of
these nutrients as are their food sources.
References for this presentation are the same as those
for this topic found in module 5 of the textbook