Download Fat-Soluble Vitamins - 35-206-202

FAT-SOLUBLE VITAMINS
CHAPTER 12
LEARNING OUTCOMES
• Define the word vitamin and list 3 characteristics of
vitamins as a group
• Classify the vitamins according to whether they are
fat or water-soluble
• List 3 important food sources for each fat- soluble
vitamin
• List the major functions for each fat-soluble vitamin
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LEARNING OUTCOMES
• Describe the deficiency symptoms for each
fat-soluble vitamin and state the conditions
in which deficiencies are likely to occur
• Describe the toxicity symptoms caused by
excess consumption of certain fat-soluble
vitamins
• Evaluate the use of vitamin and mineral
supplements with respect to their potential
benefits and risks to health
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VITAMINS: ESSENTIAL DIETARY
COMPONENTS
• Two categories
• Fat-soluble: Vitamins A, D, E and K
• Water-soluble: Vitamin B complex (8) and C
• Compare and Contrast
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Absorption of vitamins
Malabsorption of vitamins
Transport of vitamins
Storage of vitamins in the body
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VITAMIN A
• Retinoids
• Active form:
preformed Vitamin
A
• Retinal, retinol and
retinoic acid
• Dietary sources:
liver, fish oils,
fortified dairy
products and eggs
• Caroteinoids
• Provitamins-can be
converted to
Vitamin A
• Dietary sources:
dark green and
yellow orange
vegetables and
fruits
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EQUIVALENTS
• Used for some vitamins when there are multiple
forms of the vitamin so there is one common unit
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VITAMIN A NEEDS
• RDA
• Men
• 900 micrograms retinol activity equivalent (RAE)
• Women
• 700 micrograms RAE
• Daily Value (used on packaging)
• Approximately 1,000 micrograms
• Average current intake meets DRI
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Which are vitamin A
and which are beta
carotene?
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ABSORPTION, TRANSPORT AND
EXCRETION OF VITAMIN A
• Absorption
• Packaged with chylomicrons and transported via the
lymphatic system
• Transport
• Retinoids-bound to retinol binding protein
• Carotenoids-carried by VLDL
• Excretion
• Small amount in urine
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FUNCTIONS OF VITAMIN A (RETINOIDS)
• Growth and Development
• Embryonic development
• Epithelial cells and mucus production in lungs, trachea, skin,
GI tract
• Immune Function
• Maintains the ephithelium
• Increased infections w/vit A deficiency
• Dermatology
• Topical and oral medications
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FUNCTIONS OF VITAMIN A
(RETINOIDS)
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FUNCTIONS OF VITAMIN A
(RETINOIDS)
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FUNCTIONS OF CAROTENOIDS
• Provitamin A activity
• Beta carotene (most Vitamin A activity of the
carotenoids)
• NOT toxic
• Other health benefits
• Cataracts
• Lung cancer
• Macular degeneration
• Other carotenoids
• Lutein and zeaxanthin
• Lycopene
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VITAMIN A DISEASES
• Deficiencies
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•
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Night blindness
Xerophthalmia (permanent blindness)
Follicular hyperkeratosis
Impaired growth
Increased infections
Increased transmission of maternal/fetal HIV
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VITAMIN A DISEASES
• Toxicities
• Hypervitaminosis A
• Upper limit-3000 micrograms/day retinol (not
carotenoids)
• Appears w/ chronic supplement use at 5-10x the RDA
• Acute (100x RDA for a few days)
• GI upset, headache, poor muscle coordination
• Chronic (chronic use of 10x RDA)
• Joint pain, liver damage, coma, death
• Teratogenic
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VITAMIN D
• “Conditional” or prohormone
• Requirement-sunlight 2-3 times a week for 10-15
minutes
• Skin formation:
• In skin, sunlight (UV light) changes 7-dehydrocholesterol
(made from cholesterol) to vitamin D3
• Whether it is made in the skin or ingested, D3 is converted
to form 25-hydroxycholecalciferol or 25(OH)D) in the liver.
Once made, the product is released into the plasma,
where it binds to vitamin D binding protein.
• 25(OH)D travels to liver and kidney and converted to bio
active form-1,25(OH)2D (ligand for VDR, responsible for
most actions of vitamin D)
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Table 2: Recommended Dietary Allowances (RDAs) for Vitamin D [1]
Age
Male
Female
Pregnancy
Lactation
0–12 months*
400 IU
(10 mcg)
400 IU
(10 mcg)
1–13 years
600 IU
(15 mcg)
600 IU
(15 mcg)
14–18 years
600 IU
(15 mcg)
600 IU
(15 mcg)
600 IU
(15 mcg)
600 IU
(15 mcg)
19–50 years
600 IU
(15 mcg)
600 IU
(15 mcg)
600 IU
(15 mcg)
600 IU
(15 mcg)
51–70 years
600 IU
(15 mcg)
600 IU
(15 mcg)
>70 years
800 IU
(20 mcg)
800 IU
(20 mcg)
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VITAMIN D NEEDS
• The new reference intakes (RDA) for vitamin D are
based on amount need to maintain serum 25hydroxyvitamin D level of 20 ng/mL (for optimal
bone and overall health):
• 1–70 years of age: 600 IU/day (15 μg equivalent)
• 71+ years of age: 800 IU/day
• Recommendations assumes no skin synthesis of
vitamin D and refers to total intake from food,
beverages and supplements.
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ABSORPTION, TRANSPORT AND
EXCRETION OF VITAMIN D
• Absorption and Transportation
• Absorbed via micelles and transported via
chylomicrons in the lymphatic system
• Bound to a protein
• Synthesis of the active form is regulated by
parathyroid hormone and kidneys
• Excretion
• Small amount in urine and bile
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FUNCTIONS OF VITAMIN D
• Calcium and Phosphorus Homeostasis
• Aid in increasing absorption of calcium
• Aid in releasing calcium from bone, if
necessary
• Bone Health
• Immune Function (cold and flu)
• Cancer (breast, colon, prostrate)
• Heart disease
• Type 1 diabetes
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VITAMIN D DISEASES
• Deficiencies
• Children-rickets
• Adults-osteomalacia
• Toxicities
• Does not occur from sunlight or dietary
sources
• Does occur with supplementation
• Upper limit
• 4000 IU daily
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VITAMIN E
• 8 compounds
• 4 tocopherols
• 4 tocotrienols
• Dietary sources:
• Plant oils, wheat germ, asparagus,
almonds, peanuts and sunflower
seeds
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VITAMIN E NEEDS
• RDA
• 15 mg daily of alpha-tocopherol
• Daily Value
• 30 IU (approximately 20 mg)
• Adults consume approximately
2/3 the RDA
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ABSORPTION, TRANSPORT AND
EXCRETION OF VITAMIN E
• Absorption and Transportation
• Micelles into chylomicrons
• Transported via lipoproteins
• Stored in adipose tissue
• Excretion
• Bile, urine and skin
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VITAMIN E FUNCTIONS
• Antioxidant
• Reduces oxidative stress
• Other antioxidant compounds
• Glutathione peroxidase
• Selenium
• Superoxide dismutase
• Copper, Zinc and Manganese
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VITAMIN E DISEASES
• Deficiencies
• Hemolytic anemia-rare in humans
• Toxicities
• Interfere with Vitamin K and cause
hemorrhaging
• Upper limit:
• 1000 mg natural sources
• 1100 IU synthetic sources
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VITAMIN K
• Menaquinones
• Synthesized by gut bacteria
• Fish oils and meats
• Phylloquinones
• Plants: green leafy vegetables,
broccoli, peas and green beans
• Most biologically active
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VITAMIN K NEEDS
• AI
• Women
• 90 micrograms daily
• Men
• 120 micrograms daily
• Daily Value
• 80 micrograms
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ABSORPTION, TRANSPORT AND
EXCRETION OF VITAMIN K
• Absorption and Transportation
• Absorbed in small intestine, via
chylomicrons in lymphatic system.
• Transported via lipoproteins and stored in
the liver
• Excretion
• Primarily bile, small amount urine
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VITAMIN K
• Functions
• Blood clotting factors
• Bone health
• May protect the body from inflammation
• Deficiency
• Rare: long term antibiotic use or fat
malabsorption
• Toxicity
• No UL
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DIETARY SUPPLEMENTS
• Dietary Supplement Health and
Education Act of 1994 (DSHEA)
• A mineral
• A vitamin
• An amino acid
• A herb, a botanical, or a plant extract
• A combination of any of the above
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VITAMIN/MINERAL
SUPPLEMENTATION
• Individuals that may benefit
• Things to look for:
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No more than 100% Daily Value
USP certification
Diet and supplement shouldn’t exceed ULs
Check for superfluous ingredients
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