Chapter 9 - Nutrition
vitamin A and the oral cavity:
-assists in the formation of ameloblasts and odontoblasts -keeps oral tissues healthy, especially the sulcus
Ways to preserve the vitamin content of food:
-consume highly perishable produce like berries and leafy veggies soon after harvest or purchase -store fresh produce at temperatures near freezing -avoid exposure to excessive heat, alkaline substances, light, and air -cook veggies in small amounts of water, using quick cook methods
Natural forms of vitamins can be found in:
-plants -animals -fungi -bacteria
Roles of vitamins:
-some act as hormones -regulate body process -NOT sources of energy
Under certain conditions, the body can synthesize which vitamins?
-vitamin D -niacin -choline
UL for vitamin D
100
UL for vitamin E
1000 mg/day of alpha-tocopherol
AI for vitamin K
120 - men 90 - women
vitamin D RDA for adults under 70
15
RDA for vitamin E
15 mg/day of alpha-tocopherol
When were vitamins first defined? vita = necessary for life amine = a type of nitrogen-containing substance
1912
UL for vitamin A
3000
Breastfed infants should consume a supplement containing ____ of vitamin D PER DAY to reduce their risk of Rickets.
400 IU
RDA for vitamin A
700-900
Fat-soluble vitamins
A, D, E, and K
Vitamin E may decrease risk for _________.
Alzheimer's
disease/conditions that affect __________ can decrease absorption and result in deficiencies
GI tract
What is a vitamin?
a complex organic compound that regulates certain metabolic processes
tocopherols (vitamin E)
a group of four structurally similar forms of vitamin E
retinol
alcohol form of vitamin A and the most active form of vitamin A in the body
What populations are more at risk for vitamin deficiency/toxicity
alcoholics, elderly, anorexics
What are good sources of preformed vitamin A
animal foods (liver, butter, fish, liver oils, eggs)
vitamin E is an ________.
antioxidant
Vitamin D is necessary for the metabolism of calcium and phosphorus, and the production and maintenance of healthy ________.
bones
beta-carotene
carotenoid that the body can concert to vitamin A
macula of the eye contains _________, ___________, and _________.
carotenoids, lutein, and zeaxanthin
vitamin toxicity
cells saturated with vitamins cannot accept more, continuous excess consumption can cause liver damage
osteomalacia
condition characterized by softening of the bones as a result of inadequate vitamin D status in adults
Lack of vitamin A causes what?
decrease in mucus, fertility, bone growth/development, and increased risk of infection and xerostomia
biological activity
describes a vitamin's degree of potency or effects in the body
What enhances digestion/absorption of vitamin K?
dietary fat
xerophthalmia
dry eyes, can damage cornea and could lead to blindness
Vitamin A is necessary for production and maturation of what?
epithelial cells
age-related macular degeneration (AMD)
eye disease resulting in changes in the macula or the eye, causing distorted vision
T/F Vitamins CAN be synthesized by the body.
false
retinoids (preformed vitamin A)
family of compounds commonly called vitamin A (retinol, retinal, and retinoic acid)
What are fat-soluble vitamins digested and absorbed with?
fats
naturally occurring food sources of vitamin D
fish liver oils and fatty fish (especially salmon, herring, and catfish)
Other important dietary sources of vitamin E
fish, whole grains, nuts and seeds, and certain veggies
gamma-tocopherol (vitamin E)
form of vitamin E found in foods; has a significantly lower biological activity than alpha-tocopherol
menaquinone (vitamin K)
form of vitamin K found in egg yolks, butter, and beef as well as synthesized by bacteria in the large intestine
Phylloquinone (vitamin K)
form of vitamin K found in plants
food sources of vitamin D
fortified milk, cereal, orange juice, and margarine
Vitamin-A sources
fortified milk, yogurt, margarine, cereals, carrots, spinach, leafy greens, pumpkin, sweet potatoes, broccoli, mangoes, and cantaloupe
cholecalciferol (vitamin D3)
found in animal food sources
calciferol (form of vitamin D)
found in both plant and animal foods
ergocalciferol (vitamin D2)
found in plant food sources
major food sources of vitamin K:
green leafy veggies, kale, turnip greens, salad greens, cabbage, spinach, broccoli, green beans, soybean and canola oils
Full activation of Vitamin D requires what two things?
healthy liver and healthy kidneys
What can free radicals lead to?
heart attach, Alzheimer's disease, stroke
free radicals are _______
highly reactive; damage or destroy cells
Structure of a fat-soluble vitamin
hydrocarbon chain
Where does a healthy body store vitamin E
in body fat, skeletal muscle, and liver
Where are fat-soluble vitamins found?
in lipid portions of foods
Where do water-soluble vitamins dissolve?
in watery components of food and body
25-hydroxyvitamin D
inactive form of vitamin D, made in the liver from cholecalciferol
Intake of vitamin K tends to ______ with age.
increase
cystic fibrosis
inherited respiratory disease caused by a defective gene that leads to overproduction or thick and sticky mucus
vitamin-A deficient epithelial cells produce too much what?
keratin
What filters excess water-soluble vitamins and eliminates them in urine?
kidneys
Water-soluble vitamins are more or less likely to be toxic compared to fat-soluble?
less
Where is 90% of vitamin-A stored?
liver
_________ needs vitamin K to synthesize clotting factors such as prothrombin
liver
Where are fat-soluble vitamins (A, D, E, K) store?
liver and fatty tissues
What does cystic fibrosis affect?
lungs, pancreas, liver, intestines, sinuses, and reproductive organs
Other roles of vitamin E:
maintaining nervous tissue and immune system function
Vitamins are required in ________.
milligram and microgram
calcitriol (1,25-dihydroxyvitamin D)
most biologically active form of vitamin D
Are ALL vitamins amines?
no
Are vitamins metabolized for energy?
no
Is vitamin D essential?
no
Retinal binds to ________ to form ________.
opsin, rhodopsin
Vitamin E is highly susceptible to destruction by what?
oxygen, metals, light, and high temperatures
vitamin D works with what hormone?
parathyroid hormone (PTH)
carotenoids
plants contain hundreds, yellow-orange pigments in fruits and green veggies; vitamin precursors
Vitamin E protects what?
polyunsaturated fatty acids in cell membranes from being damaged by free radicals (antioxidant)
7-dehydrocholesterol (form of vitamin D)
precursor for vitamin D found in skin-UV radiation converts it into D3
bioavailability
refers to the extent to which the digestive tract absorbs a nutrient and how well the body uses it
Vitamin A precursors in plant foods are not as well absorbed as what?
retinol in animal foods
Rods convert _________ to _________.
retinol, retinal
What is the primary site for vitamin absorption?
small intestine
Vitamin D stimulates what?
small intestine to absorb calcium and phosphours
retinyl esters
storage form of vitamin A
antioxidant
substance that gives up electrons to free radicals to protect cells
oxidizing agent
substance that removes electrons from atoms or molecules such as proteins, FAs, and DNA
free radical
substance with an unpaired electron
food sources of vitamin E
sunflower seeds, almonds, plant oils (sunflower, safflower, canola, and olive oils) and products made from them (margarine and salad dressing)
vitamin D is AKA:
sunshine vitamin (considered a hormone)
multivitamin-multimineral supplement
supplement that contains two or more vitamins and minerals
menadione (vitamin K)
synthetic form of vitamin K
Vitamin A should NOT be taken in excess during pregnancy because it is a ________.
teratogen
alpha-tocopherol (vitamin E)
the form of vitamin E found in plasma and used by the body; found in most foods and vitamin E supplements
What contains rods and cones and needs retinol to function properly?
the retina
UL for vitamin K
there is no UL
Water-soluble vitamins
thiamin, riboflavin, niacin, vitamin B6, pantothenic acid, folate, biotin, vitamin B12, vitamin C, choline, carnitine, and lipoic acid
retinol-binding protein (RBP)
transports vitamin A in the blood
T/F Fat-soluble vitamins CAN cause toxicity not readily excreted.
true
T/F It is unlikely that any vitamins still need to be discovered.
true
T/F Vitamins occur naturally in foods.
true
T/F Limited amounts of water-soluble vitamins are stored.
true (exception is vitamin B12)
rhodopsin
vitamin A-containing protein that is needed for vision in dim light
Rickets
vitamin D deficiency disorder in children resulting in improper bone growth
Excessive amounts of vitamin E taken as supplements may interfere with what?
vitamin K's role in blood clotting
When can vitamin toxicity occur?
when megadoses are taken - not through food
How is vitamin-A transported?
with lipids in chylomicrons to tissues for storage
carotenemia
yellowing of the skin that results from excess beta-carotene in the body (harmless)
Is severe vitamin deficiency UNCOMMON in the US?
yes