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2 forms of Vitamin A and where they come from
- retinol FAs- animal foods
- Beta-carotene- plants
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What are retinol-FAs and beta-carotene converted to?
Retinoids
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3 types of Retinoids
- Retinol
- Retinal
- Retinoic acid
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Precursors to Vitamin A
Carotenoids
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How is Vit A important in vision?
- Maintainance of cornea
- Component of rhodopsin which is an eye protein that converts light impulses to nerve impulses & is important for color vision
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General functions of Vit A (6)
- Vision
- Cell Differentiation
- Growth & Bone Dvlpmt
- Immunity
- Antioxidant
- Regulation of Gene Expression
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What role does vit A play in cell differentiation?
It can turn on or off certain genes (esp epithelial skin cells), which affects what type of cell an immature cell will become
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Vit A affects the activity of cells that form and break down bone
T
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How does vit A affect immunity?
Maintains health of epithelial tissue
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What type of Vit A precursor is antioxidant?
Carotenoids
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Food sources of vit A
- Retinoids: liver, fish oils, eggs, fortified milk & cereal
- Carotenoids: dark green, orange/deep yellow veg, some fruits
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RDA vit A
Adults 19-30:
M= ___ ug RAE/dy
F= ___ug RAE/dy
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RDA Retinoids vs Precursor vit A
1 ug retinol = ___ RAE (retinol activity equivilants)
___ ug beta-carotene = 1 ug retinol = 1 RAE
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Symptoms ___ deficiency:
Reduced immunity
Perm blind (xerophthalmia)
Keratinization (hardening) of tissues
Growth retardation
Vit A
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Symptoms Vit A excess are only when ___ are consumed in excess
retinoids
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Permanent liver, bone, eye damage, maybe birth defects all may result from:
Excess retinoid intake
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UL of retinol
3000 mcg/day (2x DV)
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Apricots, spinach, sweet potatoes, mango are all rich in ____
Vit A
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Active form vs inactive forms of vit D (names)
- Active form: 1,25-dihydroxycholecalciferol
- -or 1,25 (OH)2 D3 or calcitriol (stored in kidney)
- Inactive: 25-hydroxycholecalciferol (stored in liver)
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What is precursor to vit D?
cholesterol
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In order for Vit D to be activated, there are ____ steps in the kidneys and liver
hydroxylation
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Vit D increases ___ & ___ absorption of calcium, and increases reabsorption of calcium from ___ to ___
- intestinal, kidney
- bone to blood
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Both vit __ and vit __ can participate in cell differentiation
A, D
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Food sources of ___ include eggs, liver, fatty fish, butter, fortified milk & cereals
Vit D
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Adult AI values of Vit D
19-50 yrs: ___ ug/dy
51-70 yrs: ___ ug/dy
71+ yrs: ___ ug/dy
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Vit D Deficiency
Reduced bone ____
____ which causes stunted growth, skeletal abnormalities
____ which causes increased fracture risk "soft bones"
- mineralization
- Rickets
- Osteomalacia
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Vit D Excess
___ : calcium deposits in ____ (3)
- Hypercalcemia
- heart, kidneys, blood vessels
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UL of Vit D supplementation
50 mcg/day
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Vit E forms (2) & most active form
- Tocopherols
- -alpha-tocopherol most active form
- Trienols
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Vit E protects ___ (3), as well as lipids, and is ___ (prevents DNA mutations)
- cell membranes, lungs, blood cells
- antioxidant
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Food sources Vit E (7)
plant oils, whole grains, nuts & seeds, avocado, spinach, broccoli
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Vits __ are stable when cooked
A, D, K
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Vits __ are not vulnerable to heat and oxidation
E
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Vit E RDA for adults 19+
15 mg/dy
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Vit E deficiency can cause:
___ nerve ___
hemolytic ___ in preterm infants
- peripheral nerve degeneration
- anemia
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Vit E is relatively non-toxic, however can interfere w/___
vit K
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Forms of Vit K
Plants:
Animals & bacteria:
Menatione:
- phylloquinones
- menaquinones
- menadione
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Vit K is important in blood clotting & ____
bone protein synthesis
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Why is vit K important for bones?
Bone protein synthesis by activating osteocalcin
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Food sources vit K (4)
- liver
- green veggies
- milk, eggs
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AI Vit K
M: ___ ug/dy
F: ___ ug/dy
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Vit K deficiency causes: (2)
- impaired clotting
- imparied bone formation
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Rare to have toxic levels of ___ unless supplementing w/high doses
Vit K
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__ is produced by intestinal bacteria but not in sufficient amts
Vit K
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How can levels of vit K be negatively affected?
- Antibiotic therapy
- Excess A or E
- Anti-coagulant meds
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__ injections are given to newborns
Vit K
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