Module 9: Vitamins Flashcards
what type of nutrients are vitamins
micronutrients
are vitamins organic or inorganic
organic (contain carbon)
how do vitamins assist is providing energy
through metabolic processes
which vitamins are fat soluble
K, A, D, E
describe fat soluble vitamins storage in the body (time, amount, place)
- stored for long periods of time, not required in diet every day
- stored in large quantities
- stored in liver and fat cells
describe water soluble vitamins storage in the body (time, amount)
- stored for short periods of time, required in diet everyday
-not generally stored in large quantities
are fat soluble vitamins more likely to be deficient or toxic
toxic
are water soluble vitamins more likely to be deficient or toxic
deficient
what are the three chemical forms of vitamin A
- retinol
- retinal
- retinoic acid
which form of vitamin A is the most active
retinol
what is a precursor to vitamin A that is found in the pigment of carrots
beta carotene
what are the functions of vitamin A
- integrity of epithelial cells
- bone growth
- cell membrane stability
- gene regulation
- vision
- immune function
what does RAE stand for
retinol activity equivalent
who needs an increased amount of vitamin A and why
- women who are pregnant and breastfeeding
- needed for epithelial tissue growth of babies
define preformed vitamin A
ready to use, not needed to be converted
what are food sources of preformed vitamin A
- animal-based foods
- fortified foods
define provitamin A
- must be converted to active form of vitamin A as needed
- ex: beta carotene
what are food sources of provitamin A
plant-based foods
what are the effects of early stages of deficiency of vitamin A on vision and can it be reversed
- night blindness
- reversible
what are effects of short term vitamin A deficiency on the cornea
cornea becomes dry and damaged
what are effects of long term vitamin A deficiency on the cornea
xerophthalmia: permanent loss of vision
describe how vitamin A assists immune function
- disease resistance, particularly for children
- production of white blood cells
describe how vitamin A assists in the integrity of epithelial cells
- epithelial tissue in the skin, lungs, and lining of the GI tract
- vitamin A aids in proliferation of cells
which vitamin is linked with cell differentiation (development of specialized cells)
vitamin A
describe how vitamin A assists with gene regulation
- role in turning genes on and off
- indirect role in the regulation of metabolism
describe how vitamin A assists with bone metabolism
stimulates osteoclasts that break down the inner part of bone
why should children 1-3 get less vitamin A than older people
- vitamin A assists in bone metabolism
- too much vitamin A can lead to poor growth in children
what is the difference between osteoclasts and osteoblasts
- osteoclasts: break down bone
- osteoblasts: build up bone
where is vitamin A stored
- fat tissue
- liver
what are symptoms of vitamin A toxicity
- liver damage
- birth defects
is provitamin A toxic
no
what can beta carotene help prevent
- heart disease
- cancer
why are smoker encouraged to avoid vitamin A
- increased risk of lung cancer in smokers
- vitamin A can cause proliferation of cells which can lead to cancer in smokers
should the general public take beta carotene supplements
no
what is the scientific name for vitamin D
cholecalciferol
what is vitamin D classified as
- vitamin
- hormone
- steroid
what is the function of vitamin D
- regulation of calcium metabolism:
- producing calbindin
- stimulating kidneys to conserve calcium
- stimulating calcium release from bone to blood
what does vitamin D stimulate the small intestines to produce and what does it do
- calbindin
- calcium-binding protein
- increases calcium absorption
how does vitamin D affect the kidneys
- stimulates kidneys to conserve calcium
- decreases urinary calcium excretion
why are bones broken down for calcium
broken down when calcium is needed for other functions throughout the body
how often do you have a completely new skeleton
every 10 years
what happens to the recommendation for amount of vitamin D as we age and why
- requirement increases as we age
- less ability to convert vitamin D into its active form
- less likelihood of adequate sunlight exposure
what food sources do we get a majority of vitamin D from
fortified foods
is vitamin D essential or nonessential and why
- non essential
- body can make it through exposure to sunlight
how does the body make vitamin D from sunlight
- cholesterol in skin combine with UV rays from the sun
- cholesterol enters bloodstream
- converted into precursor of vitamin D
- sent to liver where it is converted to another inactive form
- goes to kidneys
- converted to active form D3
what factors influence vitamin D synthesis
- distance from equator
- amount of clothing coverage
- sun block use
- cloud cover
- skin color
- age
describe rickets
- caused by vitamin D deficiency in children
- softening and deformity of long bones, bowing of legs
- inability to deposit calcium in newly formed bone
- malformation of skull, rib cage, and ends of long bones
describe osteomalacia
- caused by vitamin D deficiency in adults
- softening of bone caused by decalcification
- similar to rickets in children
is vitamin D toxicity common
no
what could cause vitamin D toxicity
overuse of supplements
what are symptoms of vitamin D toxicity
- nausea, vomiting, diarrhea
- calcification of soft tissue
why do ethnic populations have higher rates of vitamin D insufficiency
- less conversion of cholesterol to vitamin D due to melanocytes in skin
- consume less milk due to culture, many are lactose intolerant
what are chronic diseases linked with vitamin D insufficiency
- diabetes
- hypertension
where is vitamin E primarily found
cell membranes
what is the group of compounds that makes up vitamin E called
tocopherols
what are the 4 types of tocopherols
- alpha
- beta
- gamma
- delta
what are the functions of vitamin E
- antioxidant: neutralizes free radicals
- enhances immune function
- required for nerve cell development
what is the number 1 antioxidant
vitamin E
define free redicals
- unstable compounds with unpaired electrons
- attack other molecules with electrons which damages cell membranes, proteins, enzymes, and DNA
how does vitamin E act as an antioxidant
neutralizes free radical by donating electrons
describe how vitamin C and E work together to neutralize free radicals
- vitamin C gives an electron to vitamin E which gives the electron to the free radical
- vitamin C becomes radicalized, but its water soluble so it will be eliminated quickly
where can free radicals come from
- UV rays (sun)
- pollution
- stress
- poor diet
- small amounts form normal metabolism
why are smokers discouraged from taking vitamin E supplements
increase incidence of brain hemorrhage
what vitamins are smokers discouraged from taking
vitamins A and E
is vitamin E deficieny common or rare
rare
who is most likely to experience vitamin E deficiency
- premature infants
- those with insufficient stores
what condition results from vitamin E deficiency
anemia
why does vitamin E deficiency cause anemia
red blood cells become fragile and malformed and eventually rupture
what are symptoms of vitamin E deficiency
- loss of muscle coordination and reflexes
- muscle weakness
- reproductive failure
- impaired vision
what are signs of vitamin E toxicity
- headache, nausea, blurred vision
- reduced sexual function in men
- accelerated signs of aging
- inflammation of the mouth
- chapped lips
- fatigue
- GI disturbances
- muscle weakness
- increased bleeding
what is the primary function of vitamin K
blood clotting
how does vitamin K promote blood clotting
activates the protein fibrin which is required to form blood clots
what is a secondary function of vitamin K
synthesis of the bone protein osteocalcin
who requires more vitamin K: men or women
men
do childbearing women require more vitamin K than non-childbearing women
no
what population is at the highest risk of vitamin K deficiency
newborns
why are newborns at a higher risk for vitamin K deficiency
- sterile GI tract at birth: E coli produce 80% of vitamin K
- breast milk is poor source
what vitamin is given to babies at birth
vitamin K
what is a potential risk factor for vitamin K deficiency
prolonged antibiotic use
what is the most significant source of vitamin K for humans
E coli in large intestine (80%)
what vitamins are water soluble
- vitamin C
- B vitamins
which vitamins are less toxic: fat or water soluble, and why
- water-soluble are less toxic
- eliminated more often
what is the scientific name for vitamin C
ascorbic acid
describe scurvy
- disease causing death of sailors in 1800s
- caused by vitamin C deficiency
symptoms of scurvy
- bleeding gums
- tooth loss
- poor wound healing
- small hemorrhages on skin
what are the functions of vitamin C
- antioxidant
- synthesis of collagen
- facilitates iron absorption in GI tract
what vitamin in second to vitamin E as an antioxidant
vitamin C
what body system do antioxidants support
immune system
define collagen
- protein that forms connective tissues of tendons, bone, teeth, and skin
- high strength
- highly recycled in the body
what are the functions of collagen
- wound healing
- maintenance of blood vessel structure
who has an increased need for vitamin C and why
- smokers
- protects body against damaging compounds in tobacco smoke
how much more vitamin C should smokers get than non-smokers
additional 35 mg per day
what is the best known source of vitamin C
orange juice
what affects the levels of vitamin C in food
- food preparation
- vitamin C is vulnerable to heat and oxygen
why does vitamin C deficiency cause anemia
- vitamin C needed for iron absorption
- less vitamin C = less iron absorption = anemia
what are signs of vitamin C deficiency
- bleeding gums
- loss of appetite
- pinpoint hemorrhaging
- impaired growth
- weakness
- scorbutic rosary in infants
how much vitamin C is toxic
2 g per day
what often causes vitamin C toxicity
supplementing at greater than 1g per day
list all B vitamins
- B1: thiamin
- B2: riboflavin
- B3: niacin
- B5: pantothenic acid
- B6: pyridoxine
- B7: biotin
- B9: folate
- B12: cobalamine
why is there no vitamin B4
- existed at one time
- lost status as vitamin\
- compound now known as adenine (one of the nitrogenous bases)
what is a common function of all B vitamins
coenzymes or cofactors in energy metabolism
what is the scientific name for vitamin B1
thiamin
what was the first individual B vitamin identified
thiamin (B1)
what are the functions of vitamin B1 (thiamin)
- part of coenzyme thiamin pyrophosphate (TPP)
- assists in function of nerve and muscle cell activity
what is the active form of vitamin B1 (thiamin)
thiamin pyrophosphate (TPP)
what does thiamin pyrophosphate (TPP) do
- assists in metabolism of carbohydrates and some amino acids
- conversion of pyruvate to acetyl CoA
- used in Kreb’s cycle
is there an upper limit for vitamin B1 (thiamin)
no
what part of the grain kernel has the most B12 vitamins
germ
who often experiences thiamin (vitamin B1) deficiency
- malnourished individuals
- alcoholics
define beriberi
- vitamin B1 (thiamin) deficiency
- heart becomes enlarged, fluid accumulates beneath skin, and muscles weaken/atrophy
- wet and dry beriberi
what type of beriberi primarily affects the cardiovascular system
wet beriberi
what type of beriberi primarily affects the nervous system
dry beriberi
define wernicke-karsakoff syndrome
- severe thiamin (vitamin B1) deficiency in alcoholics
- causes ataxia, memory loss, and muscle atrophy
what is the scientific name for vitamin B2
riboflavin
what are the two activated forms of vitamin B2 (riboflavin)
- flavin mononucleotide (FMN)
- flavin adenine dinucleotide (FAD)
what is the main function of vitamin B2 (riboflavin)
activated forms (FMN and FAD) used as electron shuttles in energy metabolism
where is flavin mononucleotide (FMN) in the electron transport chain
protein complex 1
where is flavin adenine dinucleotide (FAD) in the electron transport chain
protein complex 2
what can destroy vitamin B2 (riboflavin)
ultraviolet light and irradiation
what does vitamin B2 (riboflavin) deficiency often occur in conjunction with
other water-soluble vitamin deficiencies
what are the symptoms of vitamin B2 (riboflavin) deficiency
inflammation of membranes (sore throat, cracked mouth, swollen tongue)
what is the scientific name for vitamin B3
niacin
what are the 2 chemical forms of vitamin B3 (niacin)
- nicotinamide
- nicotinic acid
what are the functions of vitamin B3 (niacin)
- release energy from macronutrients through coenzymes in metabolic pathways
- synthesis of fatty acids
what are the two niacin-containing coenzymes used in metabolic pathways
- nicotinamide adenine dinucleotide (NAD)
- nicotinamide adenine dinucleotide phosphate (NADP)
what is the upper limit for vitamin B3 (niacin)
35 mg per day
why is vitamin B3 (niacin) often found in preworkout
causes flushing and tingling which can make some people ready to workout
what are sources of vitamin B3 (niacin)
animal proteins
what essential amino acids can be used to synthesis vitamin B3 (niacin) in the body
tryptophan
what condition is caused by vitamin B3 (niacin) deficiency
pellagra
what are the symptoms of pellagra
- vitamin B3 (niacin) deficiency
- 4D’s: diarrhea, dermatitis, dementia, death
what vitamin deficiency was common in southeastern US during the early 1900s due a diet poor in it
vitamin B3 (niacin)
does vitamin B3 (niacin) have toxicity symptoms
yes
how do people often get vitamin B3 (niacin) toxicity
overconsumption of supplements or fortified foods
what are symptoms of vitamin B3 (niacin) toxicity
- flushing: redness of face, arms, and legs
- tingling sensations
- liver injury
what are high doses of nicotinic acid prescribed for
cholesterol reduction
what is the scientific name for vitamin B6
pyridoxine
what is the key function of vitamin B6 (pyridoxine)
transamination: synthesis of nonessential amino acids
what is the active form of vitamin B6 (pyridoxine)
PLP
what are secondary functions of vitamin B6 (pyridoxine)
- synthesis of glucose and some types of lipids
- breakdown of glycogen for use in body
- production of serotonin
- hemoglobin synthesis
what are deficiency symptoms of vitamin B6 (pyridoxine)
- anemia
- depression
- dermatitis
- convulsions
- weakened immune response
what are toxicity symptoms of vitamin B6 (pyridoxine)
- nerve damage: numb feet or hands
- ataxia: inability to walk
are toxicity symptoms of vitamin B6 (pyridoxine) reversible
many symptoms are NOT reversible
what is the scientific name for vitamin B9
folate
what are the two forms of vitamin B9 (folate)
- folate
- folic acid
define folate
naturally occurring form of vitamin B6 (folate)
define folic acid
synthetic form of vitamin B6 (folate)
which form of vitamin B6 (folate) is easier to absorb
folic acid
what are the important functions of vitamin B6 (folate)
- needed for DNA replication during cell division
- red blood cell synthesis
- central nervous system formation during fetal development
what does DFE stand for
dietary folate equivalent
who has increased requirements for vitamin B9 (folate)
- women planning on becoming pregnant
- pregnant and lactating women
what conditions occurs with vitamin B9 (folate) deficiency
macrocytic anemia
define macrocytic anemia
- large and immature red blood cells fewer in number than should be
- causes red blood cells to have difficulty moving through capillaries
what is the umbrella term for conditions of newborns associated with vitamin B9 (folate) deficiency during pregnancyy
neural tube defects
what are the two types of neural tube defects
- spina bifida
- anencephaly
define spina bifida
failure of spinal cord to close completely
define anencephaly
lack of or incomplete development of brain and skull
has the prevalence of neural tube defects increased or decreased over time and why
- decreased
- due to folate fortification in foods
what is the scientific name for vitamin B12
cobalamin
what element is in vitamin B12 (cobalamin)
cobalt
where is vitamin B12 (cobalamin) often synthesized
bacteria in the large intestine
where is vitamin B12 (cobalamin) found naturally
foods of animal origin (proteins)
what is needed for vitamin B12 (cobalamin) to be absorbed
intrinsic factor
what is the antidote for cyanide poisoning
vitamin B12 (cobalamin)
what are the functions of vitamin B12 (cobalamin)
- converts folate to active form
- maintains myelin sheath which insulates nerve fibers
what does the myelin sheath do
- insulates nerve fibers
- increases speed of nerve impulses
describe how vitamin B12 (cobalamin) is digested and absorbed
- released from dietary protein in the stomach by pepsin and HCl
- vitamin bound to intrinsic factor which protects it from degradation until absorption
- absorbed in lower ileum
what happens to vitamin B12 (cobalamin) absorption as we age and why
- absorption decreases
- lower intrinsic factor production and HCl secretion
what are conditions associated with vitamin B12 (cobalamin) deficiency
- macrocytic anemia
- pernicious anemia
define pernicious anemia
anemia due to lack of intrinsic factor
what conditions can reduce intrinsic factor
- genetic defect
- aging
- bariatric surgeries