Chapter 9 Flashcards
Fat soluble vitamins
Vitamin A, D, E, K
Fat soluble vitamins require what for absorption
Bile and dietary fat
Vitamin A function
- Vision
- regulate growth and cellular differentiation
- necessary for maintenance of epithelial tissue
Vitamin A sources
- found preformed
- animal products or supplements or in precursor form from plant foods
Eggs, dairy, liver, fish
Orange, yellow and dark green veggies
Retinoids
The chemical forms of preformed vitamin A: retinol, retinal and Retinoic acid
-liver, fish, egg yolk and milk
Animal products
Carotenoids
Natural pigments synthesized by plants and many micro-organisms. They give yellow and red-orange fruits and veggies their colour.
- a precursor converted to retinoids
- provitamin A
- function as antioxidants
Ex: beta-carotene, provitamin converted into vitamin A
Beta-carotene
A carotenoid that’s has more provitamin A activity than other carotenoids. It also acts as an antioxidant.
Vitamin A digestion steps
- Preformed vitamin A and carotenoids are bound to proteins in food. To be absorbed they must be release from the rite in by pepsin
- In small intestine, released retinol and carotenoids combine with bile acids to form micelles which facilitate diffusion into mucosal cells.
- Preformed vitamin A is absorbed more than carotenoids.
- Once inside mucosal cells, much of Beta-carotene is converted to retinoids.
- Preformed vitamin A and carotenoids absorbed are transported from intestine by chylomicrons to body tissues
Retinol-binding protein
A protein that is necessary to transport vitamin A from the liver to other tissues
Rhodopsin
A light absorbing compound found in the retina of the eye that is composed of the protein Opsin loosely bound to retinal
-rhodopsin helps transform the energy from light into a nerve impulse that is sent to the brain
Night blindness
The inability of the eye to adapt to reduced light, causing poor vision in dim light
-caused by vitamin A deficiency
Keratin
A hard protein that makes up hair and nails
-mucus secreting cells during vitamin A deficiency become keratinized and hard
All _______tissues are affected by a deficiency in vitamin A
Epithelial
Xerophthalmia
A spectrum of eye conditions resulting from vitamin A deficiency that may lead to blindness. An early symptom is night blindness, and as deficiency worsens, lack of muscle leaves the eye dry and vulnerable to cracking and infection
- abnormal jaw bone growth in children
- increased infections
Keratomalacia
Softening and drying and ulceration of the cornea resulting from vitamin A deficiency
Vitamin A and D in gene expression
Have functions that regulate gene expression
- cell differentiation: immature cells change in structure and function to become specialized by changing gene expression (on and off)
- vitamin A helps ensure healthy eyes
- vitamin D promoters strong bones
Unconverted carotenoids circulate in blood and may function as
Antioxidants
Retinol activity equivalents (RAE)
The amount of retinol, B-carotene, alpha-carotene or B-cyrptoxanthin that provides vitamin A activity equal to 1 microgram of retinol
Toxicity of vitamin A symptoms
- acute
- chronic
Nausea, vomiting, headache, dizziness, blurred vision, and lack of muscle coordination
Weight loss, muscle and joint pain, liver damage, vision defects, dry scaling skin
Due to excess supplementation
Hypercarotenemia
A condition in which carotenoids accumulate in the adipose tissue, causing the skin to appear yellow-orange, especially the palms of the hands and the soles of the feet
- not dangerous
- when intake lowers, colour disappears
Caused by excess B-carotene
Vitamin D is produced where
In the skin by exposure to ultraviolet light
- inactive until modified in liver and kidneys
- essential in the diet only hen exposure to sunlight is limited or the body’s ability to synthesize it is reduced (winter)
Natural food sources of vitamin D include
Liver, fatty fish like salmon, cod liver oil and egg yolks. These foods contain cholecalciferol
Cholecalciferol
The chemical name for vitamin D3. It can be formed in the skin of a sinks by the action of sunlight in a form of cholesterol called 7-dehydrocholesterol
Principle function of Vitamin D
Maintain levels of calcium (helps calcium be absorbed) and phosphorus in the blood
-low blood calcium stimulates parathyroid hormone release which stimulates vitamin Activation
(Bone health)
-changes gene expression: intestine: turns on genes for calcium absorption. Bone: turns on genes for bone breakdown
-working of the brain, heart, stomach, pancreas, skin and reproductive organs
-immune system
-functions as a hormone
Parathyroid hormone
A hormone released by the parathyroid gland that acts to increase blood calcium levels
Vitamin D receptor
A protein to which vitamin D binds. This receptor vitamin complex is then able to bind to DNA and alter gene expression
To increase blood calcium levels
Rickets
A vitamin D deficiency disease in children that is characterized by poor bone development because of inadequate calcium absorption
-causes bowed legs, reduced height, weak bones
Osteomalacia
A vitamin D deficient disease in adults, characterized by a loss of mineral from bones. Bones bend. It causes bone pain, muscle aches, and an increase in bone fractures
Vitamin E function
A fat-soluble vitamin with an antioxidant function
Protects lipids in membranes
- RBC, WBC, nerve cells, lungs cells
- role in modulating immune response
- reducing inflammation
- allowing cells to communicate
- regulating genes
- inhibiting an early step in blood clot formation
Tocopherol
Chemical name for vitamin E
- vitamin E absorption depends on normal fat absorption
- once absorbed, vitamin E is incorporated into chylomicrons
Two groups of vitamin E in foods
Tocopherols
Tocotienols
Alpha-tocopherol
The most common form of vitamin E in the human body that is absorbed
Dietary sources of Vitamin E
Nuts, plant oils, leafy greens and wheat germ
Vitamin E deficiency issues
- membrane changes
- nerve degradation
- hemolytic anemia in newborns
Hemolytic anemia
Anemia that results when red blood cells break open
- poor muscle coordination
- weakness
- impaired vision
(Newborns)
Coagulation
The process of blood clothing
Phylloquinone
Menaquinones
The form of vitamin K found in plants
The forms of vitamin K synthesized by bacteria and found in animals
Dietary sources of vitamin K
Liver, leafy green veggies like spinach, Kale, and Brussels sprouts, and veggie oils, kiwi
Prothrombin
-what is needed to produce this
A blood protein required for blood clotting
- vitamin K is a coenzyme needed for the production of this
- creates thrombin used to make fibrin threads to form blood clots
Deficiency of vitamin K causes
Blood does not clot!!!!
Rhodopsin
Visual pigment in the eye
-when light strikes rhodopsin, it initiated a series of events that result in a nerve signal being sent to the brain, which allows us to see
Vitamin A
Vitamin A deficiency skin symptom
Dry and hard skin
Medications using vitamin A
Retin A
Accutane
Deficiency of vitamin A may be cause by….
Insufficient intake of fat, protein or zinc
Excess vitamin D
Causes high calcium concentrations in blood and urine, deposition of calcium in soft tissues such as the blood vessels and kidneys, and cardiovascular damage
/increase risk of high blood pressure, some cancers, type 1 diabetes, heart disease, arthritis, IBS, MS
When to take Vitamin D supplements
All months with “r”
September-April
Excess vitamin E in supplements
No reported effects from food but large supplements doses can interfere with blood clotting
Vitamin K1/K2 functions
- fat soluble
- production of clotting factors
- synthesis of proteins involved in bone formation and breakdown
- inhibit blood vessel calcification
- regulate cell growth
- decrease risk of fractures due to osteoporosis
- reduce risk of atherosclerosis and cancer
Anticoagulants
Blood thinners like warfarin that inactivates vitamin K
Excess of Vitamin K
No reported effects from food but large doses can interfere with blood clotting
Functional foods
Provide health benefits beyond basic nutrition
Phytochemcials
Zoochemicals
Health promoting substances found in plant foods
Health promoting substances found in animal foods
Phytochemicals-Carotenoids
- Yellow-orange pigments found in plants (and in some fish and birds)
- antioxidants; some have vitamin A activity
- B-carotene, alpha-carotene, B-cryptoxanthin, lycopene, lutein, zeaxanthin
Suggested health benefits: reduced risk of certain cancers, cardiovascular disease and age related eye disease
Phytochemicals-Polyphenols (flavonoids)
- anthocyanidins (blue and red)
- blue, red or yellow pigments found in veggies, fruits, wine, grape juice, chocolate, and tea
- strong antioxidants
- some also have anti-inflammatory and anti cancer properties
Suggested health benefits: protecting against cancer and cardiovascular diseases
Phytochemicals-Indoles and Alliums
- sulfur-containing phytochemicals
- rich in cruciferous vegetables and garlic, onions, leeks and shallots
- stimulating the activity of enzymes that detoxify carcinogens
- insoles inactivate estrogen (estrogen exposure increases cancer)
Alliums
- boost the activity of cancer-destroying enzymes
- prevent future bacteria from converting nitrates to nitrites
- protect against oxidative damage
- garlic, onions and leeks
Phytoestrogens and other plant hormones (phytochemcials)
- phytoestrogens include isoflavones and lignins: soybeans, flaxseed and barley
- suggested functions: blocking estrogen receptors, may protect against certain cancers and osteoporosis
Choosing a phytochemical-rich diet
- eat more veggies and fruits with colour!
- choose whole grain foods: more phytochemicals and antioxidants than fruits and veggies
- eat protein foods especially plant based
- add nutraceuticals, designer foods, photochemical supplements, and photochemical-fortified foods with caution
Chocolate
Cocoa-antioxidant, rich in minerals like magnesium, zinc, copper, iron, poly phenols
- helps with stress, mood, pain, insulin sensitivity, BP
- NOT CADBURY MINI EGGS
