Exam 3: Chapter 12 Flashcards
What four vitamins are fat soluble?
Vitamins A, D, E and K
Main functions of Vitamin A:
- Growth and Development
- Cell Differentiation
- Vision
- rhodopsin
- Immune Function
- Maintenance of the epithelium
- Use of vitamin A analogs in Dermatology
What are the main functions of Vitamin D?
- 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
What are the main functions of Vitamin E?
- Antioxidant
- Stops lipid peroxidation (chain reactions) caused by free radicals
- Works with vitamin C
What are the functions of Vitamin K?
- Synthesis of blood clotting factors
- Bone metabolism
Food sources of Retinoids/Vitamin A:
- liver
- fish oils
- fortified dairy products
- eggs
Food sources of carotenoids/Vitamin A:
- dark green
- yellow orange vegetables and fruits
Food sources in Vitamin D:
- Fatty fish
- cod liver oil
- fortified dairy products
- fortified breakfast cereals
Food sources of Vitamin E:
- Plant oils (e.g., canola)
- wheat germ
- avocado
- almonds
- peanuts
- sunflower seeds
Food sources of Menaquinones/Vitamin K:
- fish oils and meats
Food sources of Phylloquinones/Vitamin K:
- green leafy vegetables
- broccoli
- peas
- green beans
Vitamin A Deficiencies
- 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.
Vitamin A Toxicities
- Hypervitaminosis A
- Upper Limit: 3000 micrograms/d retinol
- Acute, chronic and teratogenic toxicity
Vitamin D deficiencies:
- Children: rickets
- Adults: osteomalacia
Vitamin D Toxicities:
- Does not occur from sunlight or dietary sources
- Can occur with supplementation
- Upper Limit: 4000 IU
- Calcium deposits in soft tissues
Vitamin E Deficiencies:
- Hemolytic anemia – rare in humans
- Pre-term infants and smokers are most susceptible
- Immune function impairment and neurological changes
Vitamin E Toxicities:
- Can interfere with Vitamin K and cause hemorrhaging
- Upper Limit:
- 1000mg natural sources (1100 IU from synthetic sources)
Vitamin K Deficiency:
- Deficiency is rare
- Newborns; long-term antibiotic use; fat malabsorption
Vitamin K Toxicity:
- No UL
What is the difference between Vitamin D2 and Vitamin D3?
- 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)
How is Vitamin D3 formed and what is the requirement to form this?
- 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
What is the active form of Vitamin D?
calcitriol
What compounds compose Vitamin E?
- 8 compounds
- 4 tocopherols
- 4 tocotrienols
What compounds besides Vitamin E can serve as antioxidants?
- Glutathione peroxidase
- Selenium
- Superoxide dismutase
- Copper, Zinc and Manganese
What compounds compose Vitamin K?
-
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
Which compound of Vitamin K is the most biologically active?
Phylloquinones
What ingredients are part of a dietary supplement?
- 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
What types of individuals may require a dietary supplement?
- 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
What is the most active form of Vitamin E?
Alpha-tocopherol is the most active form in humans.
What is the definition of a Vitamin?
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.
