Chapter 7 vitamins Flashcards
why are vitamins important?
they are required for growth and health
what happens when we have low vitamin intake?
we develop a deficiency
what is the response to correcting deficiencies?
you see dramatic improvements in health
true or false: we only need a very small amount of a given vitamin
true
what are fat soluble vitamins?
A, D, E, K
What are water soluble vitamin?
B and C
how are fat soluble vitamins absorbed?
they are absorbed like fats. they are first absorbed into the lymph and then into the blood.
how are fat soluble vitamins transported and stored?
they are transported with protein carriers in watery fluids and are stored in the liver or fatty tissues
how are fat soluble vits excreted?
they are not readily excreted and tend to build up in the tissues
How do we usually reach toxic levels of fat sol vits?
they likely are caused by supplements.
rarely occur from food.
what are our requirements for fat sol vits?
we need them in periodic doses, maybe weeks or even months, since our body can draw on its stores
how are water soluble vits absorbed?
they are absorbed directly into the blood
how do water sol vits transported and stored?
they travel freely in watery fluids and are not usually stored in the body.
how are water sol vits excreted?
they are readily excreted in the urine
how do we reach toxic levels of water sol vits?
toxicity is unlikely but when it happens it is caused by supplements
what are our requirements for water sol vits?
they are needed in frequent doses (1 to 3 days) because the body foes not store most of them to any extent.
what happens to the cornea without vit A?
The cornea becomes cloudy (keratinization) and dry (xerosis) and the eventual result is irreversible blindness (xeropthalmia)
keratinization
when the cornea becomes cloudy
Xerosis
when the eye becomes dry
xeropthalmia
irreversible blindness.
what role does vit A play in eyesight?
vit A is necessary for regenerating rhodopsin in the retina after a visual signal is sent to the brain.
night blindness
without vit A it takes a long time to regenerate rhodopsin so we have a hard time adjusting to be able to see in dim light.
what are some functions of vit A?
Eyesight regulates gene expression like which proteins cells make cell differentiation immunity growth(bones and teeth)
cell differentiation
cells develop to perform specific functions
what are the effects of vit A deficiency on cells?
decreased cell division
deficient cell development
what are the health consequences of a vit A deficiency?
night blindness keratinization xerophthalmia impaired immunity reproductive and growth abnormalities exhaustion death
what are the effects of vit A toxicity on cells?
overstimulated cell division
what are the health consequences of a vit A toxicity?
skin rashes hair loss hemorrhages bone abnormalities birth defects fractures liver failure death
beta carotene
provitamin
precursor of vit A
what are the functions of beta carotene?
the same as vit A plus it also functions as an antioxidant
hypercarotenemia
too much carotene in blood
not harmful
what are some food sources of Vit A?
liver
eggs
fortified milk
what are some food sources of beta carotene?
dark green leafy vegetables (spinach, broccoli, collard greens)
Orange fruits and vegetables (carrots, sweet potatoes, pumpkins, mango, cantaloupe, apricots)
what is the function of vit D
it maintains blood calcium which is needed in all cells. increases ca absorption from gut decreases ca loss through the kidney Gene regulation bone development
how does vit D effect bones ?
it releases ca from the bones and/or deposits ca into bones according to blood ca level
what is the role of vit D and vit K in bone development?
Vit D-Ca absorption and bone formation
Vit K- incorporating Ca into bone
what are the effects of Vit D deficiency?
rickets in children
osteomalacia in adults
rickets
bowed legs and beaded ribs (Ca on ribs and not in ribs)
osteomalacia
soft bones
what is the result of vit D toxicity?
calcium deposites in joint, heart, blood vessels, lungs, and kidneys which all ultimately lead to death
what are some food sources of Vit D?
milk
dairy products
fatty fish
some fortified foods
what are some non-food sourced of Vit D?
Sunlight
What are some factors that affect vitamin D synthesis?
old age air pollution tall buildings (cities) cloudy skies geography (high or low latitudes) being homebound seasons skin pigment (darker skin makes less vitD) sunscreen time of day So pretty much anything that keeps sun rays from hitting your skin.
when are free radicals produced?
during normal metabolism and by exposure to sunlight and pollutants
what do antioxidants do?
they help protect us from free radicals that damage other molecules.
which antioxidants and minerals act as antioxidants?
beta carotene
Vit E
Vit C
mineral selenium
Why is vit K important?
it’s necessary for blood clotting
excess vit E
makes blood too thin
increases risk of hemorrhaging
excess vitamin K
makes blood too thick
increases risk of clots and stroke
food sources of Vit E
PUFA oils
nuts/seeds
heating oil can destroy vit E
food sources of vit K
leafy greens
what are he functions of vit C?
connective tissue formation
antioxidant
UL of vit C
look up
RDA adults of vit C
look up
how many mg of vit C should you intake to prevent scurvy?
10 mg
does vit C prevent colds?
no its a placebo effect
what are some food sourced of vit C?
citrus melons green peppers berries broccoli potatoes cabbage tomatoes
what are the 8 B vitamins?
thiamin riboflavin niacin folate B6 B12 biotin pantothenic acid
B vitamins serve as:
coenzymes in energy metabolism
what is the cause of a thiamin deficiency?
beri beri
what are the symptoms of Beri-Beri?
muscle weakness
enlarged heart
apathy
sometimes edema
what are food sources of thiamin?
thiamin is found in any nutritious foods
what is wernicke-korsakoff syndrome caused by?
alcohol abuse
if thiamin is deficient, _____ probably is also deficient
riboflavin
what destroys riboflavin?
light
what are some good sources of riboflavin?
milk and dairy products
what is the function of a coenzyme?
when they are present they allow the various parts of an enzyme to come together to form an the enzyme
niacin deficiency causes
pellagra
what are the symptoms of pellagra (4Ds)
dermatitis
diarreah
dementia
death
food sources of thiamin
most whole foods
whole and enriched grains
food sources of riboflavin
dairy products
whole and enriched grains
food sources of niacin
most meats
whole and enriched grains
what is the function of folate?
DNA synthesis for new cells
red blood cell division and maturation
what happens when you have a deficiency in folate?
some neural tube defects
spina bifida
an excess of folate can:
compensate for B12 deficiency and RBC appear normal but the nerve damage that arises from a B12 deficiency will continue
what is the function of vit B12?
maintain covering of nerve cells
synthesis of RBC
what happens when you have a B12 deficiency?
nerve damage
irreversible paralysis
anemia
what are 2 ways that a B12 deficiency can happen?
inadequate dietary intake (vegans)
poor absorption: pernicious anemia
what are some requirements for B12 absorptions?
adequate stomach acid
intrinsic factor
pernicious anemia
a B12 deficiency that arises when (intrinsic factor) IF is lacking
why are elderly susceptible to B12 deficiency?
not enough stomach acid
need supplements
what are food sources of B12?
animal products
what are some food sources of folate?
enriched grains
green leafy vegetables (foliage)
fruits and vegetables
what is the result of vit B6 toxicity?
nerve damage
numbness
what are food sources of B6?
many nutritious foods
what can vitamins be destroyed by?
cooking heart air light acidity freezing
is depleted soil a problem for preserving nutrients?
no. fruits and vegetables make the nutrients that they have
where should you be getting your nutrients from?
food is best not supplements
isolated vitamins in supplements sometimes cause
unexpected problems
when are supplements recommended?
people with specific deficiencies newborns (vitK) vegans (B12 and D) pregnant women (iron and folate) elderly with poor diets restricted diets extended illnesses
what are some good habits for preparing veggies?
steam over water
use the cooking water in soup
microwave veggies
refrigerate milk when not using it
what are some ways we shouldnt prepare veggies ?
leaving peeled and cut veggies in water
boiling frozen veggies
store pasta in clear glass jar on kitchen counter
