Fat
Soluble
Vitamins
By Jennifer Turley and Joan Thompson
© 2016 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.
Chemical Forms. Intake Need. Functions. Deficiency. Toxicity. Food
Sources.
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.Dietary records: Demonstrate low/high intake and/or
confirm a metabolic or physiological problem that creates
an altered need.
2.Clinical deficiency or toxicity symptoms: Are compatible
with low/high dietary intake or altered need.
3.Biochemical tests: Such as blood levels, tissue levels &
urine levels demonstrate low/high body levels of the
nutrient.
4.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
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)
DRI: 700-900 µg RE/day
(>UL)
Approx. <500 µg RE/day
RDI: 5,000 IU
>3,000 µg RE/day
Hypovitaminosis A
Normal vision, gene
expression, reproduction,
Bone & tooth: Impaired
embryonic development,
growth
epithelial cell
Central Nervous System: maintenance, growth, and
Night blindness, complete immune function.
blindness (Xerophthalmia)
GI System: Diarrhea
25 mg beta-carotene (proImmunity: Depressed
vitamin A is safe to take
immunity, more
daily if you are not a
infections
smoker or drinker).
Skin: Hyperkeratosis
(thickened skin)
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)
RDI: 400 IU = 6.5 µg
>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
Normal calcium and
Hypervitaminosis D
phosphorus balance and cell characterized by high levels of
metabolism.
25(OH)D from supplementation
Cardio-Vascular: High blood
calcium
Needs are based upon an
Central Nervous System:
inadequate exposure to
Weakness
sunlight.
GI System: Nausea, vomiting,
Sunlight not implicated in
anorexia
toxicity.
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
Membrane
Antioxidant
& Stabilizer
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)
RDI: 30 IU
>1,000 mg/day
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 antiblood clotting medication
and increases hemolysis
Premature infants:
hemolytic anemia
Adults: not well
characterized
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
(<66% of DRI)
DRI: 90-120 µg
Approx. <60 µg/day
/day
Toxicity
(>UL)
Not Determined
RDI: 90 µg
Cardio-Vascular: Normal blood
Increases clotting clotting & bone
time, hemorrhaging metabolism
with cut or injury
Poorly described in adults
GI System: High levels from
supplemented menadione
causes jaundice and liver
damage in infants
Cardio-Vascular:
Interference with anti-blood
clotting medication
Adult deficient, adequate, toxic values
Vitamin K: Sources
• Green leafy & cruciferous
vegetables
• Soybeans
• Some plant oils
Vitamin K in Foods
Adult DRI: 90-120 µg/day
Some
Summary Points
• 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