Vitamins Flashcards
what are vitamins?
Vitamins are micronutrients (organic compounds) required by the body to carry out a range of normal functions
what are factors that determine the amount of vitamin that are readily available?
– Source (animal vs. plant)
– Sunlight
– Moisture
– Growing conditions
– Plant’s maturity at harvest
– Packaging and storage
what are reasons why we wouldn’t get enough vitamins?
- dietary interactions
- drug interactions
- physiological state
- disease
- genetic
- food processing
what is a provitamin?
a substance that may be converted within the body to a vitamin (is the inactive form)
what are the water-soluble and the fat-soluble vitamins?
- water: B1, B2, B3, B5, B6, B7, B9, B1, C
- fat: A, D, E, K
differences in absorption of water-soluble and fat-soluble vitamins.
fat:
- are solubilized by bile salts (make micelles)
- released at enterocyte brush border membrane
- incorporated into chylomicrons
- secretion into lymphatics and ultimate uptake by the liver (can accumulate in body)
water:
- can go through enterocytes
- go to blood vessels
- doesn’t stay long since it secreted in urine
what are the active and precursors of vitamin A?
- active: retinoids
- pre: carotenoids
vitamin A is important for:
- Vision: night and day
* Becomes part of the retina
* Keeps eye surface healthy
* Allows night and color vision - Immune function
* Produce immune cells to fight microorganisms - Cell Production and differention
* Regulates production of enzymes, blood carrier proteins,
And structural
Proteins (like those in the skin) - Skin
* Needed to replace epithelial cells of your skin - Reproduction
* Keep reproductive tracts healthy
* Women:maintain fertility; Men:Sperm production
* Embryo development - Bones
* Helps produce bone cells
* Required For bone remodeling a increase In osteoclasts
how does vitamin A affect vision?
- is a precursor of rhodopsin, the photopigment
found in rods within the retina of our eye that helps us to see at night. - Without vitamin A, “night blindness” occurs
what are sources of vitamin A?
- fruits and vegetables (carrot and sweet potato very high)
- liver
- oat/bran
- milk
what are the effects of vitamin A deficiency?
- eyes: Xerophthalmia (blindness)
- skin: hyperkeratosis
- immune: vulnerable to infection
- other: Growth retardation, bone deformations, defective teeth, and kidney stones
what are the effects of vitamin A toxicity?
- symptoms: Fatigue, vomiting, abdominal pain, bone and joint pain, loss of appetite, Skin disorders, headache, blurred or double vision, and liver damage
- is a teratogen
- causes skin discoloration
- acne treatment
how is vitamin D activated?
by liver and kidney
what are the functions of vitamin D?
- Essential for bone health (important for calcium absorption)
- Helps regulate Insulin formation and secretion
what are sources of vitamin D?
- exposure to sunlight
- fortified foods (milk, cereals)
- oily fish, egg yolk, liver
- supplements
what happens with vitamin D deficiency and toxicity?
- deficiency: rickets in children, osteomalacia and osteoporosis in adults
- toxicity: hypercalcemia
what are the different forms of vitamin E?
- 8 similar compounds but only alpha-tocopherol required for humans
what are the functions of vitamin E?
- antioxidant (protect cell membrane form free radicals)
what is the recommended daily intake of vitamin E?
- 15mg/day for adult
- 19mg/day for breastfeeding
what are food sources of vitamin E?
-nuts/seeds
- vegetable oil
- whole grain/wheat germ oil
- fruits and vegetables
- animal products
when does vitamin E deficiency occurs? what about toxicity?
- deficiency: occurs with fat malabsorption or rare genetic disorders
- toxicity: nontoxic and adverse effects have not been found, but can interfere with blood clotting and causes lung injury when inhaled
what are the forms of vitamin K?
K1 and K2
what are the functions of vitamin K?
- blood clotting (necessary for the synthesis of thrombin)
- bone health
what are the dietary recommendations of vitamin K?
- men: 120 mg/day
- women: 90 mg/day