1. Fat Soluble Vitamins
Module 5.1 A D E K

2. Vitamins
An organic* substance-coenzyme and/or regulator of metabolic processes
Do not supply calories (energy)
Vitamins are classified by their biological and chemical activity, not their structure-made of single units not long chains
Vitamins must be absorbed by the body in order to perform their functions.
Approximately 40–90% of vitamins are absorbed in the small intestine.
Some vitamins are absorbed in inactive provitamin or vitamin precursor forms that must be converted into active forms by the body
Two classes: water soluble; fat soluble
Water soluble not stored in body
8 B vitamins, Vitamin C
Fat soluble stored in the liver and fat tissue
Vitamin A, D, E, K
* organic – contains carbon

3. Comparison of Vitamins in the Body
Fat-soluble vitamins require fat in the diet to be absorbed.
Micelles transport to intestinal wall for absorption
Escorted by chylomicrons via lymph into blood to the liver
Stored in the liver and body fat
absorbed into lymph, many require protein carriers, not readily excreted,
intake deficiency signs and symptoms occur more slowly
toxicity is possible even when intake is normalized.
Water-soluble vitamins may require transport molecules or specific molecules in the GI tract.
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. 3

4. DIAGNOSING Nutritional Deficiency or Toxicity
Dietary records: Demonstrate low/high intake. Medical records can confirm a metabolic or physiological problem that creates an altered need.
Toxicity often found with history of excessive intake of supplements
Clinical deficiency or toxicity symptoms: Observable deficiency in actual patients; compatible with low/high dietary intake or altered need. Deficiency attributed to lack of proper nourishment seen in poverty situations, young children and frequent pregnancies.
Toxicity-intake of single supplements such as Vitamin C, E
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.

5. Fat-Soluble - Vitamin A
Functions: vision, maintenance of healthy epithelial tissue (skin and cells lining cavities), sperm production, fetal development, immune response, hearing, taste, and growth
Two types
Retinoids –preformed / active form- animal form
Carotenoids –precursor- plant form
RETINOIDS - preformed or active form
Retinol – active form of vitamin A
Retinal – vision- combines with opsin to form pigment rhodopsin
Retinoic acid- cellular growth and maintenance; skin: wrinkles (Retin-A), acne
Conversion reactions: Retinol ↔ Retinal → Retinoic Acid
The amount of vitamin A present in foods is expressed as retinol activity equivalents (RAE) - a measure of the amount of retinol the body will derive from food.
RAE Equivalents: Based on active form retinol
1 RAE = 1 µg retinol
1 RAE = 2 µg supplemental beta-carotene
1 RAE = 12 µg dietary beta-carotene

6. Vitamin A Fat-Soluble Vitamins
Carotenoids – Vitamin A precursor
Intestinal cells convert carotenoids into vitamin A.
Found in plant products
Beta-carotene: an orange pigment found in plants that is converted into vitamin A inside the body. Beta-carotene is also an antioxidant
Sources: apricots, cantaloupe, carrots

7. Vitamin A Functions Vision, hearing, taste
Growth; Embryonic development
Gene expression
Immune function
Maintenance of healthy epithelial tissue (skin, internal & external surface linings)
Reproduction (sperm and fetal development)
Antioxidant properties

8. Fat-Soluble Vitamins - Vitamin A
Up to a year’s supply can be stored; 90% in the liver.
Transported through the blood by retinal binding protein.
Vitamin A toxicity can lead to consequences.
Hypercarotnemia – orange hue to skin – result of excessive intake – often seen in vegetarians
Vitamin A deficiency result of insufficient intake of vitamin A, fat, protein or zinc
Deficiency occurs after reserves depleted.
Consequences include night blindness and reduced resistance to infection, skin conditions, poor bone growth
Xerophthalmia - dry eyes- condition where the eye fails to produce tears. Cornea thickens- interferes with light entering the eye-results in irreversible blindness
Medications made from vitamin A, such as Retin A or Accutane, can cause serious side effects – birth defects, increase in LDL cholesterol

9. Vitamin A Deficiency vs Toxicity
(<66% of DRI)
Approx. <500 µg RE/day
Adequacy
DRI: µg RE/day
RDI: 5,000 IU
Toxicity
(>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)
Normal vision, gene expression, reproduction, embryonic development, epithelial cell maintenance, growth, and immune function
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
25 mg beta-carotene (pro-vitamin A is safe to take daily if you are not a smoker or drinker).
Adult deficient, adequate, toxic values

10. Vitamin A in Foods Retinol: (animal) Beta-Carotene: (Plant)
Adult DRI: µg RE/day
Vitamin A in Foods
Retinol: (animal)
Fortified milk, cheese, butter, margarine
Eggs
Liver 
Beta-Carotene: (Plant)
dark green leafy vegetables
broccoli, deep orange fruits, & vegetables

11. Fat-Soluble Vitamins Vitamin D
Both a vitamin and a hormone
Functions in bone production and maintenance osteomalacia
Increases bone mineralization
Body synthesizes with sunlight (5-15 mins)
Deficiency diseases
In children, rickets
In adults, osteomalacia
Assists in the absorption of dietary calcium
Increases intestinal absorption of calcium (Absorption from food in intestines)
Re-absorption of calcium in kidneys
Regulates and balances calcium and phosphorus availability in blood
Increase phosphorus excretion rickets
Reduces cell division (Antiproliferative) – of cancer cell formation and promotes cellular differentiation of new cells (Prodifferentiation)

12. Vitamin D Synthesis
Vitamin D3 (cholecalciferol) synthesized by the cholesterol in skin’s exposure to sun.
Cholecalciferol converted to calcidiol in liver
Calcidiol converted to calcitriol in kidneys to active form of Vitamin D

13. Vitamin D Deficiency vs Toxicity
There is an epidemic of vitamin D deficiency
Vitamin D Deficiency vs Toxicity
Deficiency
(<66% of DRI)
Approx. <3 µg/day
Adequacy
DRI: 15 µg/day
RDI: 400 IU = 6.5 µg
Toxicity
(>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
Normal calcium and phosphorus balance and cell metabolism
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
Needs are based upon an inadequate exposure to sunlight.
Sunlight not implicated in toxicity.
Adult deficient, adequate, toxic values

14. Vitamin D in Foods Food sources:
Fortified products like milk, margarine, & some cereals
Eggs & fatty fish
Self-synthesis with unprotected peak sunlight exposure
Adult DRI: 15 µg/day

15. Fat-Soluble Vitamins Vitamin E-Tocopherol
Vitamin E chemistry
A family of alpha, beta, gamma, delta tocopherols & tocotrienols.
Alpha-tocopherol is believed to be the most active form.
Known as a vitamin in search of a disease
Needed for growth and fertility
Vitamin E deficiency in newborns might result in hemolytic anemia.
Antioxidant
Absorbed from small intestine and transported by chylomicrons
Sources: vegetable oils, nuts, seeds, margarine, soybean
Deficiencies of the nutrient are rare.
risk of deficiency:
Premature infants not receiving vitamin E from mothers.
Fat malabsorption diseases.
certain blood disorders.

16. Vitamin E Functions Membrane Antioxidant & Stabilizer And at the
molecular level

17. Vitamin E in Foods Food sources: Nuts Wheat germ Seeds
Plant oils
Wheat germ
Fortified cereals
Vegetables
Adult DRI: 15 mg/day

18. Vitamin E Deficiency vs Toxicity
(<66% of DRI)
Approx. <10 mg/day
Adequacy
DRI: 15 mg/day
RDI: 30 IU
Toxicity
(>UL)
>1,000 mg/day
Premature infants: hemolytic anemia
Adults: not well characterized
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

19. Fat-Soluble Vitamins Vitamin K
Found in several forms, including phylloquinon and menaquinone.
BLOOD-CLOTTING system of the body.
Works with vitamin D to regulate calcium levels in the blood. Calcium required in blood clotting mechanisms
Deficiencies rare-obtained both in the diet and via the intestinal bacteria. Antibiotics can decrease flora and production of Vitamin K
Newborn babies are the one group that is commonly susceptible to a vitamin K deficiency.
A baby’s digestive tract is free of bacteria until birth.

20. Vitamin K Deficiency vs Toxicity
(<66% of DRI)
Approx. <60 µg/day
Adequacy
DRI: µg /day
RDI: 90 µg
Toxicity
(>UL)
Not Determined
Cardio-Vascular:
Increases clotting time, hemorrhaging with cut or injury
Normal blood clotting & bone metabolism
Poorly described in adults
GI System: High levels from supplemented menadione causes jaundice and liver damage in infants
Interference with anti-blood clotting medication
Adult deficient, adequate, toxic values

21. Vitamin K in Foods Food Sources: Green leafy & cruciferous vegetables
Soybeans
Some plant oils
Adult DRI: µg/day