Exam 3: Chapter 12

Question 1

What four vitamins are fat soluble?

Answer 1

Vitamins A, D, E and K

Question 2

Main functions of Vitamin A:

Answer 2

• Growth and Development
• Cell Differentiation
• Vision
  
  • rhodopsin
• Immune Function
  
  • Maintenance of the epithelium
• Use of vitamin A analogs in Dermatology

Question 3

What are the main functions of Vitamin D?

Answer 3

• Calcitriol is the active form
• Calcium and Phosphorus Homeostasis•
  
  • Aids in increasing absorption of Ca & P
  • Aids in releasing Ca & P from bone, if blood levels are low
• Bone Health
• Immune Function
• Chronic diseases

Question 4

What are the main functions of Vitamin E?

Answer 4

• Antioxidant
  
  • Stops lipid peroxidation (chain reactions) caused by free radicals
  • Works with vitamin C

Question 5

What are the functions of Vitamin K?

Answer 5

• Synthesis of blood clotting factors
• Bone metabolism

Question 6

Food sources of Retinoids/Vitamin A:

Answer 6

• liver
• fish oils
• fortified dairy products
• eggs

Question 7

Food sources of carotenoids/Vitamin A:

Answer 7

• dark green
• yellow orange vegetables and fruits

Question 8

Food sources in Vitamin D:

Answer 8

• Fatty fish
• cod liver oil
• fortified dairy products
• fortified breakfast cereals

Question 9

Food sources of Vitamin E:

Answer 9

• Plant oils (e.g., canola)
• wheat germ
• avocado
• almonds
• peanuts
• sunflower seeds

Question 10

Food sources of Menaquinones/Vitamin K:

Answer 10

• fish oils and meats

Question 11

Food sources of Phylloquinones/Vitamin K:

Answer 11

• green leafy vegetables
• broccoli
• peas
• green beans

Question 12

Vitamin A Deficiencies

Answer 12

• Night blindness
• Xerophthalmia (irreversible blindness)
• Follicular hyperkeratosis
• Bitot’s spots, which are dry, foamy areas in the eye
• dry eye membranes, corneal dryness, softening of the cornea and eventually blindness.

Question 13

Vitamin A Toxicities

Answer 13

• Hypervitaminosis A
• Upper Limit: 3000 micrograms/d retinol
• Acute, chronic and teratogenic toxicity

Question 14

Vitamin D deficiencies:

Answer 14

• Children: rickets
• Adults: osteomalacia

Question 15

Vitamin D Toxicities:

Answer 15

• Does not occur from sunlight or dietary sources
• Can occur with supplementation
• Upper Limit: 4000 IU
  
  • Calcium deposits in soft tissues

Question 16

Vitamin E Deficiencies:

Answer 16

• Hemolytic anemia – rare in humans
• Pre-term infants and smokers are most susceptible
• Immune function impairment and neurological changes

Question 17

Vitamin E Toxicities:

Answer 17

• Can interfere with Vitamin K and cause hemorrhaging
• Upper Limit:
• 1000mg natural sources (1100 IU from synthetic sources)

Question 18

Vitamin K Deficiency:

Answer 18

• Deficiency is rare
• Newborns; long-term antibiotic use; fat malabsorption

Question 19

Vitamin K Toxicity:

Answer 19

• No UL

Question 20

What is the difference between Vitamin D₂ and Vitamin D3_?

Answer 20

• Vitamin D2 in Foods:
  
  • Fatty fish, cod liver oil, fortified dairy products and some fortified breakfast cereals
• Vitamin D3 is formed in skin from cholesterol:
  
  • Sunlight changes 7-dehydrocholesterol to cholecalciferol
  • Travels to liver and then kidneys, where converted to bioactive form (calcitriol)

Question 21

How is Vitamin D₃ formed and what is the requirement to form this?

Answer 21

• Vitamin D3 is formed in skin from cholesterol:
  
  • Sunlight changes 7-dehydrocholesterol to cholecalciferol
  • Travels to liver and then kidneys, where converted to bioactive form (calcitriol)
• Requirement: sunlight 2-3 times/week for 10-15min
  
  • Several factors influence this

Question 22

What is the active form of Vitamin D?

Answer 22

calcitriol

Question 23

What compounds compose Vitamin E?

Answer 23

• 8 compounds
  
  • 4 tocopherols
  • 4 tocotrienols

Question 24

What compounds besides Vitamin E can serve as antioxidants?

Answer 24

• Glutathione peroxidase
• Selenium
• Superoxide dismutase
• Copper, Zinc and Manganese

Question 25

What compounds compose Vitamin K?

Answer 25

• Menaquinones
  
  • Synthesized by bacteria in colon (10%)
  • From fish oils and meats
• Phylloquinones
  
  • From plants: green leafy vegetables, broccoli, peas, and green beans
  • Most biologically active

Question 26

Which compound of Vitamin K is the most biologically active?

Answer 26

Phylloquinones

Question 27

What ingredients are part of a dietary supplement?

Answer 27

• a supplement is defined as any product intended to supplement the diet that contains one or more of the following ingredients:
  
  • A vitamin
  • A mineral
  • An amino acid
  • An herb, a botanical, or a plant extract
  • A combination of any of the above

Question 28

What types of individuals may require a dietary supplement?

Answer 28

• Women with excessive bleeding during menstruation may need iron
• Women who are pregnant or breastfeeding may need folate and iron
• Vegans may need extra calcium, iron, zinc and Vitamin B12
• Newborn infants may need a single dose of Vitamin K
• Individuals with lactose intolerance may need Vitamin D and Calcium supplements

Question 29

What is the most active form of Vitamin E?

Answer 29

Alpha-tocopherol is the most active form in humans.

Question 30

What is the definition of a Vitamin?

Answer 30

Vitamins are essential, organic substances needed in small amounts in the diet. They are NOT a source of energy. They instead aid in metabolism as well as in the growth, development, and maintencance of body tissues.