Chapter 12 Fat Soluble Vitamins

Question 1

Vitamin K (overview)

Answer 1

• Synthesized by Bacteria in the colon and absorbed
• Role in Coagulation process
• Role in calcium-binding potential

Question 2

Vitamin K (sources)

Answer 2

Quinones family
Plylloquinone: Plant derived
Menaquinone: Animal derived
Menadione: Synthetic form (Rx from MD)

Question 3

Vitamin K (functions)

Answer 3

Helps synthesis of blood clotting proteins
Fibrinogen –> fibrin (traps RBC & platelets)
Thrombin – activated by prothrombin
Prothrombin – vitamin K dependent
Koagulation = vitamin K

Question 4

Vitamin K (Deficiency, toxicity)

Answer 4

Deficiency Is rare

• -Possible with long term antibiotics
• -Leads to hemorrhaging (bleeding)

Question 5

Vitamin K (sources)

Answer 5

Sources

• -50% from food: Liver, green leafy vegetables, cabbage family, milk
• -50% synthesized by bacteria in large bowel

Question 6

Vitamin K (toxicity)

Answer 6

Toxicity
One way – Prescription of Menadione
Causes breakdown of RBC
RBC remnants accumulate and cause nerve damage

Question 7

Dietary Supplements

Answer 7

Dietary Supplement Health and Education Act of 1994 (DSHEA)

• -A minerals
• -A vitamin
• -An Amino acids
• -A herb, a botanical, or a plant extract
• -A combination of all the above

*They have to be proven to be harmful to de taken off the market

Question 8

Vitamin/Mineral Supplementation

Answer 8

Things to look for:

• -No more than 100% of Daily Value
• -USP certification  standards in production of supplement
• -Diet and supplement shouldn’t exceed ULs
• -Check for superfluous ingredients

Question 9

Vitamin A (retnoid carotenoid)

Answer 9

Retinoids
–Active form: preformed Vitamin A
–Retinal(reproduction), retinol(vision) and retinoic acid(growth)
–Dietary sources: liver, fish oils, fortified dairy products and eggs
–Animal origin
›Retinyl ester = vitamin A + FA
Carotenoids
–Provitamins can be converted to Vitamin A
›Needs to be some activation in body for it to be used as Vit A
–Dietary sources: dark green and yellow orange vegetables and fruits

Question 10

Functions of Vitamin A (Retinoids)

Answer 10

•	Growth and development
•	Cell differentiation 
•	Vision
•	Immune function 
•	Dermatology
Carotenoid functions
–Beta-carotene
›Decrease risk of some cancers, eye diseases, and CVD

Question 11

Vitamin A (deficiencies & toxicity)

Answer 11

Deficiencies 
–Night blindness
–Xerophthalmia (permanent blindness)
›	Dryness from the inside out 
–Follicular hyperkeratosis
›	Buildup of keratin in hair follicles 

Toxicity
•Depends if from retinol or beta-carotene
Retinol
› Stored in liver  lead to liver failure  hypervitaminosis A

Beta-Carotene
›Stored in adipocytes  build up called hypercarotenemia
–Due to overzealous supplementation
›Margin of safety 80-300%
›Upper limit: 3000 micrograms/day retinol

Question 12

Vitamin D - calciferol

Answer 12

•	Prophormone 
•	Fat soluble 
•	Essential in diet
Sources:  Fatty fish, cod liver oil, fortified dairy products and some fortified breakfast cereals
•	Can be synthesized by body
–	Requirement – sunlight 2-3 times a week for 10-15 minutes
Chemistry
–Provitamins & related compunds
›7-dehydrocholesterol (precursor)
–Form of cholesterol in skin 
›Cholecalciferol (inactive vitamin D3)
›Calcitriol (active form of vitamin D)

Question 13

Functions of Vitamin D

Answer 13

•Regulates blood calcium at 1%
–Along with the parathyroid hormone
–Regulates calcium + phosphorus absorption
–Reduces kidney excretion of calcium
–Regulates calcium deposition in bones
•Bone mineralization 
–Development & maintenance
•Influences normal cell development 
–Linked to reduction of breast, colon, and prostate cancer

Role in Bone Formation
• Causes calcium + phosphorus to deposit in the bones
– Strengthens bones

Question 14

Vitamin D deficiency

Answer 14

Rickets is the result of low vitamin D 
–	Bones fail to calcify normally
›	Bone softness
›	Breastfed infants with little sun exposure
›	Bowing legs

Osteomalacia (soft bones)
– Rickets-like disease in adults
– Bones lose minerals and become porous

Question 15

Vitamin D toxicity

Answer 15

hypervitaminosis D
–	No risk of toxicity from sun exposure
–	Increased vitamin D leads to increased calcium absorption 
–	Calcium stores in kidneys and joints
–	Monitor supplementation 
–	Adult margin of safety – UL 50µg/day

Question 16

Vitamin E - Introduction

Answer 16

Misconceptions 
–	Many claims – some not fact
–	Cannot improve physical performance
–	Enhance sexual performance
–	Slow or prevent aging
–	Slow progression of Parkinson’s 

Antioxidant
– Prevents breakdown of cellular membranes

Question 17

Vitamin E

Answer 17

Chemistry
–Tocopherols
›	α alpha * most active in humans
›	β beta
›	γ gamma    		 Not readily converted to a
›	δ delta

Question 18

Vitamin E (Functions)

Answer 18

–Antioxidant 
›	Stabilizes cell membranes
›	Removes free radicals
–Reduces oxidative stress
–Other antioxidant compounds
›	Glutathione peroxidase
–Selenium 
›	Superoxide dismutase
–Copper,  Zinc and Manganese

Question 19

Vitamin E (Toxicity & deficiency)

Answer 19

Toxicity
– Rare
– UL 1000mg/day
•Can at times interrupt Vit K and cause hemorrhage

Deficiency
–Hemolytic anemia
› Breakdown of red blood cell