Chapter 7; Fat Soluble Vitamins Flashcards
the primary effect of vitamin A deficiency is impaired [..]
vision
500k become blind, and half die within 12 months as a result of other conditions related to vitamin A deficiency (children especially vulnerable)
low vitamin A also impairs the [..] system, increasing affected children’s risk of dying from [..] diseases, particularly measles, respiratory infections, and diarrheal disease
immune
infectious
biofortification is the process by which the nutritional quality of food crops is improved through [..] management, conventional plant [..], or modern [..]
land
breeding
biotechnology
genetic engineering allows scientists to alter a plants [..] to produce a desired effect
genes
in the case of golden rice, two genes have been inserted into the rice genome, which allows it to produce [..] [..], a source of [..] [..], within the endosperm of the rice grain kernel.
beta carotene
vitamin A
golden rice is named for the intense yellow color of the [..] [..] stored within the seeds of the genetically engineered plant
beta carotene
[..] women in the high risk countries are also particularly susceptible to vitamin A deficiency, especially during the last [..] months of pregnancy when the developing fetus is taking up increasing levels of vitamin A and other nutrients from the mother’s blood supply. consequently, pregnant women can develop night [..] during this time
pregnant , three, blindness
these initiatives include short term interventions such as [..] supplementation and long term efforts such as [..]
vitamin
biofortification
vitamins are [..] compounds (compounds containing both carbon-carbon and carbon-hydrogen bonds) that are needed in [..] quantities for very specific functions, such as the maintenance of [..] and [..] process in the body
organic, small
regulatory , metabolic
vitamins (and minerals) are considered [..]-nutrients, because they are required in much [..] amounts than [..]-nutrients (carbohydrates, fat, protein, and water).
micro, smaller, macro
in nearly all cases, human cells cannot [..] vitamins, so it is essential to obtain them through [..]. the few vitamins manufactured by the body (or by intestinal bacteria) are not produced in amounts [..] to meet our needs
synthesize
diet
sufficient
if we don’t consume enough of a vitamin or are unable to adequately absorb or utilize it, we may develop symptoms characteristic of an [..] or [..] of that vitamin
insufficiency
deficiency
macronutrients are different from vitamins because of their [..] structures that the body must break down into [..] units before they can be utilized for [..] or other functions
complex
individual
energy
vitamins are different from macronutrients because they are already [..] units
individual
macronutrients are also different (including water) from vitamins, because they are also incorporated into [..] of the cell - lipids , for example, are incorporated into cell membranes - but vitamins do not have this role in cellular structure.
structures
membranes
are vitamins a source of energy
yes
even though vitamins are not a source of energy, we need a number of them to [..] energy from macronutrients as well as to provide many [..] and [..] functions in the body. vitamins are also necessary for proper cell [..], [..], and [..].
extract
regulatory, metabolic
cell, development, growth
the bioavailability, or the degree to which nutrients can be [..] and [..] by the body, is influenced by many factors, including physiological and dietary conditions.
absorbed, utilized
the presence of disease, chronic alcohol abuse, and age related physiological changes can [increase or decrease] bioavailability
decrease
the bioavailability of nutrients may also be affected by the [..] of other nutrients or food component that can enhance or reduce [..] or by food [..] practices such as whether you cook a food or eat it raw
presence
absorption
handling
vitamins are commonly grouped according to their [..] - or ability to disperse or dissolve in water. it is an important determinant of how vitamins are [..] and [..] in the body. also affects where the vitamins are [..] in the body and, potentially, the risk of [..] (adverse effects from getting too much)
solubility, absorbed, transported
stored, toxicity
of the [..] currently identified vitamins, [..] dissolve in fat and are stored in body tissue. these fat-soluble vitamins (namely, vitamins A, D, E, and K)
14
four
vitamins B, choline, and vitamin C - which [..] easily in water based solutions such as [..] - are called water soluble vitamins
disperse
blood
vitamin A is involved in [..] and cell [..] (the process by which stem cells, [..] cells produced from bone marrow, become progressively more specialized for [..] in particular tissues). functions as a [..]
eyesight, differentiation
unspecialized, functions
hormone
vitamin D involves [..] growth and maintenance, cell [..], and [..]; functions as a [..]
bone
development. immunity
hormone
vitamin E is an [..]
antioxidant
vitamin K helps with blood [..] and [..] formation
clotting
formation
because fat-soluble vitamins are not […] in water, they generally need the presence of dietary [..] and the assistance of [..] acids to be [..] effectively. once absorbed, just like fats, they typically leave the small intestine in [..] via the lump
soluble, fat, bile, absorbed
chylomicrons
fat soluble vitamins, aren’t generally [..] as easily as [..] soluble vitamins, which means that some fat soluble vitamins are more likely to cause [..]. rarely occurs with the exclusive consumption of vitamins that are naturally present in food - mostly, it is the result of consuming fortified foods and supplements at levels that [..] established tolerable upper intake levels (ULs)
excreted, easily
toxicity
naturally, exceed
when we take in more of a fat soluble vitamin than wee need, it-again, like fat-is stored in fatty [..] and the [..], from which it is [..] when the body needs it. and because the body may have significant stores of some fat soluble vitamins, deficient symptoms and disease may take [..] to appear than with water soluble vitamins, which are generally not stored in [..] amounts.
tissues, liver
released
longer, significant
although each vitamin has its own distinct functions, [..], and mechanism of [..], there are some general properties to keep in mind
metabolism, action
basically; fat soluble vitamins (A, D, E, & K)
- dissolves in [..]
- [..] amounts necessary for good health
- absorption occurs in the [..] intestine
- leave the small intestine in [..]
- often present in [..] portion of foods
- stored in tissue; toxicity possible when consumed in [..]
- lipids - small - small - chylomicrons - fatty
- excess
vitamin A is is stored primarily in the [..], it encompasses a group of fat soluble compound composed of [..] and several [..]
liver
retinoids
carotenoids
retinoid compounds are retinol, retinal, and retinoid acid.
yes
retinol is the only retinoid present in [..] amounts in our diet, and it is referred to as performed vitamin A because it is already in an [..] form in foods . once it is absorbed, we can readily (and reversibly) convert it to retinal, and retinal is irreversibly converted to retinoic acid. in contrast, the provitamin carotenoids (primarily beta carotenoids) have vitamin activity only [..] conversion in the body into one of the forms of the vitamin (retinol, retinal, or retinoic acid)
significant , active
after
the only source of vitamin A in plant foods are the provitamin A [..] 80%
carotenoids
the only source of preformed vitamin A, retinoids are foods of [..] origin and [..] foods. then the retinol (stored in the liver) and retinal (needed for vision) are readily interconverted within our body cells . then reinoic acid’s primary functional form in our body
animal
fortified
beta carotene is converted into [..] in our body after it has been absorbed.
retinal
Carotenoids are naturally found in the [..], [..], and [..] pigments of fruits and vegetables as well as in dark leafy [..].
yellow, orange, red
greens
Beta carotene is converted into [..] in our body after it’s been absorbed.
retinal
In the United States, approximately [..] of vitamin A is consumed as [..] vitamin A from fortified foods and supplements and foods that naturally contain retinol.
2/3
preformed
Preformed vitamin A is highest in liver, but [..], [..], and [..] foods containing fat are also good sources. In the United States and Canada, reduced fat milk and yogurt must be [..] with vitamin A to make up for the loss of this vitamin during the removal of the [..].
liver,
fish eggs, and dairy
fortified
fat
although the exact means by which carotenoids promote human health are currently uncertain, they may provide benefits through their ability to function as [..] in the body, which help protect cells from [..] caused by highly unstable molecules called free [..]
antioxidants
radicals
free radicals are reactive molecules with unpaired [..] that attempt to pair up with other molecules, atoms, or individual electrons to create a stable state
electrons
stable
free radicals are generated from many sources:
- during normal [..] metabolism (mitochondrial)
- present in air [..] and [..] (cigarette) smoke
- [..] light
- some [..]
- [..] responses
energy
pollution, tobacco
UV
drugs
immune
although excess free radicals can have significant deleterious effects, we actually need some of the free radicals generated in the body for several important functions, such as ensuring cellular [..] and killing [..]
communication
bacteria
at high levels, free radicals can cause damage known as [..], which can alter [..] and destabilize cell [..]. oxidative damage can lead to chronic diseases such as [..] and [..] disease, so eating a [..] rich diet that contains beta carotene and other antioxidants may reduce the risk of those disease
Do not take supplements!
- research has shown that beta carotene supplements actually increase the risk of some types of cancer in people who smoke cigarettes.
oxidation
DNA, membranes, cancer, heart
plant
ample dietary intake of carotenoids also appear to provide some [..] to the skin from the damaging effects of UV radiation from sunlight
protection
the molecules that lose its electron (stolen from a free radical molecule) have been [..] creating a new free radical. creates a [..] reaction. an antioxidant can then donate an electron without becoming [..] and [..].
oxidized, chain, unstable , reactant
people in developing countries are prone to develop [..] A because they often have little access to preformed vitamin A and beta carotene
(even in US, nutrition surveys suggest that many of us could benefit from higher vitamin A intake closer to the RDA)
hypovitaminosis
the hallmark symptoms of vitamin A deficiency affect the [..]
eye
night blindness occurs due to problem in the synthesis of [..] . in addition, the changes in protein synthesis resulting from a deficiency of vitamin A decrease the production of [..] in tears, which results in the cornea of the eye [..] . if the deficiency continues, the affected cornea can become ulcerated and essentially melt away, causing [..] and [..] blindness. leading cause of [..] in children worldwide
rhodopsin, mucus, drying
scarring, permanent
cornea ulcerations generally develop [..] as a result of [..] vitamin A deficiencies. they occur most frequently in children aged [..]-[..] years and typically cause blindness. in contrast, night blindness and other signs of eye disorder tend to occur with [..] standing, [more or less] severe vitamin A deficiencies. those signs are most common in children between the ages [..] and [..] years and generally do not lead to blindness
suddenly, severe, 1-4
long, less, 3 and 6
nevertheless, children who show any signs of vitamin A deficiency are at very high risk of [..] due to impaired [..] and an increased likelihood of [..]. therefore, to prevent these potentially severe consequences of vitamin A deficiency, effective interventions are best aimed at [..] aged children (behind the developed of golden rice)
death
immunity
infections
preschool
the symptoms of vitamin A deficiency include impaired immunity and rough, dry, or scaly [..] resulting from a loss of [..] in the mucous membranes. this last symptom - know [..] - occurs in the epithelial cells that cover the surface of our bodies (for example, the cornea of the eye) and line body cavities
skin
moisture
keratinization
without sufficient vitamin A, epithelial cells cannot [..] properly and as a consequence, they become filled with a fibrous structural protein called [..]. these are the same type of proteins that make up our nails and even the horns of animals
develop
keratin
if vitamin A deficiency common or rare in the US
rare
however, the dietary guidelines for Americans report that many individuals consume vitamin A in amounts below the estimated average requirement (EAR), which represents the average intake to meet daily requirements for just half of healthy individuals.
since the excess intake of vitamin A also has consequences, the UL for vitamin A for adults 19 years and older is set at […] mcg RAE
3000
when people consume too much vitamin A, they develop [..] A, which mostly occurs after regular use of supplements containing large quantities of vitamin A but can rarely occur with excessive intake of animal foods high in retinol content (such as liver)
hypervitaminosis
the potential effects of hypervitaminosis A are largely defects or weaknesses in [..] , leading to osteoporosis or fractures.
bones
in pregnant women, intake of vitamin A above the UL can have teratogenic effects (substances capable of interfering with [..] development, increasing risk of birth defects). thus, pregnant women are cautioned about the use of supplemental vitamin A or [..] compounds, including those that are used to treat acne. excess intake of provitamin A as beta carotene from plant sources has not been demonstrated to cause toxicity but may only temporary turn skin [..] or [..]
fetal, retinoids
yellow or orange
vitamin D is often called the “[..] vitamin” because with exposure to ultraviolet (UV) light, it can be produced from [..] in the skin.
(most of us meet at least some of our vitamin D needs this way, but with limited sun exposure or impaired synthesis, it becomes important to consume sufficient vitamin D through our diet)
sunshine
cholesterol
whether acquired through synthesis in the skin or through foods, vitamin D must be activated in the [..] and [..] to fulfill its biological functions in the body
kidneys
liver
although sunlight can be significant source of vitamin D, the RDAs - established to maintain bone health and normal calcium metabolism in health people - are set on the basis of [..] sun exposure.
minimal
in 2010, the Health and Medicine Division of the National Academies of Sciences, Engineering, and Medicine increased the RDA for vitamin D for ALL age groups - it was increased three fold to 600 IU ([..] mcg), e.g. for adults in the [..]-[..] years age range
15
19-50
it is difficult to meet those RDAs from food alone, because vitamin D is present in very [..] foods naturally. some of the best sources include [..] fish (such as salmon, tuna, and mackerel) and fish liver oils.
few, fatty
Beef liver, cheese, eggs, and some mushrooms (particularly those exposed to UV light) contain small amounts of vitamin D
alternatively, most Americans get dietary vitamin D from fortified foods - most of the US milk supply fortified with vitamin D (100 IU, or [..] mcg, per cup). this is the result of most of the US milk fortification program that was instituted in the 1930s in the US to reduce the incidence of [..], characterized by bone [..] and muscular [..]
2.5
rickets, malformations
weakness
vitamin D plays a key role in the growth and maintenance of [..] by maintaining blood concentrations of [..] involved in bone development, such as calcium and phosphorus. in addition, vitamin D works in combination with other [..] and [..] in bone growth and maintenance ,
bone , minerals
nutrients and hormones
vitamin D actually functions as a hormone because like hormones, it is [..] in one part of the body but carries out its regulatory effects [..].
made
elsewhere
because it is made from [..], vitamin D is a member of the [..] family of hormones (which includes estrogen, testosterone, and cortisol, among others)
cholesterol
steroid
vitamin D also plays an important role in the regulation of [..]. most in the body is stored in bone, with less than 1% circulating in the [..]. although its low level in blood may seem inconsequential, the circulating calcium is critical for normal [..] and [..] functioning and therefore myst be maintained.
calcium , blood
muscle and nerve
maintanence in the blood;
- inactive vitamin D enters [..] and it transported to the [..]
- conversion to the [..] form of vitamin D begins in the [..]
- the active hormonal form of vitamin D (calcitriol) is produced in the [..]
(vitamin D must be [..] to its native form by the liver and kidneys)
circulation , liver
active ,liver
kidneys
metabolized
the effects of calcitriol ([..] vitamin D) on the kidneys and bone require the cooperative action of [..] hormone;
- parathyroid glands; parathyroid [..] is released from the parathyroid gland in response to [..] blood calcium levels, stimulating the kidneys to increase the production of [..]
- kidney; calcitriol increases [..] uptake from urine
- bone; calcitriol increases calcium [..] from bone
- intestine; calcitriol increases [..] of calcium form the intestines
active, parathyroid
hormone, low, calcitriol
calcium
release
absorption
when calcium concentrations in blood decrease, more vitamin D is converted into [..] (the active hormonal form of vitamin D), which will [..] blood calcium by acting on bone, the small intestine, and the kidneys
calcitriol
increase
(for this reason, you will often find calcium supplements that also contain vitamin D)
calcitriol also works with parathyroid hormone to [..] calcium excretion by the kidneys and [..] its release from bone to raise blood calcium concentrations
decrease
Increase
it is estimated that calcitriol (and by association, vitamin D) is involved in regulating the synthesis of [..]% if all proteins in the body
5%
consequently, calcitriol is required for normal [..] development and [..] function and is critical for other [..] and [..] systems, including the brain, the heart, the nervous system, the reproductive organs, the skin, and muscle. maintaining vitamin D levels in the elderly increases muscle [..] and function and appears to reduce the risk of [..]
cell, immune
organs and body
strength, falls
evidence is also accumulating that vitamin D is necessary for regulating [..] function. sufficient intake and stores of vitamin D may [..] the risk of a number of important diseases, including cancer, autoimmune disease, kidney disease, type 2 diabetes, and even cardiovascular
cardiovascular
reduce
as many as [..]% of Americans older than 11 years may be vitamin D deficient and about another [..]% in that age range may be on the verge of deficient . some individuals are particularly at risk of developing a deficiency, including those who avoid vitamin D - fortified [..] drinks (because of allergies, intolerance, or a vegan diet), people with dark skin (because the [..] that darkens skin can interfere with the body’s ability to make vitamin D from sunlight), and those with little sun exposure or who regularly use sunscreen
6%, 20%
dairy, melanin
evidence is emerging that complete avoidance of sun exposure not increases risk of vitamin D deficiency but also may increase all cause [..]. however, the American academy of dermatology association recommends obtaining vitamin D through [..] and potentially [..]
mortality
diet , supplements
although sunscreen can block UV rays and reduce the risk of skin [..], it also [..] vitamin D synthesis
cancer,
prevents
other groups at risk of vitamin D deficiency include infants who are exclusively [..], because breast milk is not a rich source of vitamin D, and the elderly, who have reduced ability to [..] vitamin D even when exposed to [..]. many elderly individuals are also more likely to stay indoors and therefore have less opportunity to synthesize vitamin D
breastfed
synthesize, sunlight
having extremely low levels of vitamin D can, over time, cause serious [..] diseases.
e.g. [..] legs, [..] bones, and other [..] malformations.
bone
bowed, soft, skeletal
rickets is caused by low vitamin [..], where it leads to impairments in the maturation and mineralization of cartilage in regions of the bone where [..] is occurring, causing the characteristic “bowed” legs or “knocked” knees
D
growth
in adults, vitamin D deficiency can cause osteomalacia, in which the bone mineral is being depleted, causing the bones to become [..] or [..] and putting people at risk of [..] or [..], as well as creating pain in the pelvis, lower back, and legs
soft , weak
fractures or falls
hypervitaminosis D 0 is likely the result of [..] use rather than food intake or sun exposure
supplements
the establish UL for vitamin D is set at 4000 IU ([..] mcg) for males and females [..] years and older.
100
9
the symptoms of hypervitaminoses vary but may include loss of [..], [..] loss, irregular [..], and frequent [..]. having to much vitamin D can also increase levels of calcium in the blood,, which leads to [..] of the soft tissue and damage to the heart and blood vessels and the formation of kidney stones
appetite, weight , heartbeat , urination
calcification
a diet that meets the DRI of [..] IU per day guarantees that “virtually everybody” gets enough of the fat soluble vitamin
600
taking vitamin D doesn’t [..] the risk of cancer and other health problems linked to low vitamin D
decrease
vitamin E encompasses a group of fat soluble compounds found primarily in [..] oils. the compounds are known as [..]
vegetable
tecopherols
[..]-tocopherol is the only form of vitamin E that [..] in humans because it is the only form that has been shown to [..] vitamin E deficiency symptoms. for this reason, alpha tocopherol is the only form defined by the Food and Nutrition Board of the Institute of Medicine as meeting [..] vitamin E requirements
alpha
functions, reverse
human
some foods (such as breakfast [..]) are fortified with vitamin E, but vitamin E is also found naturally in [..] based oils - primarily those from nuts and seeds (safflower and sunflower oils are food sources) and products made with these oils (such as margarine and salad dressing). other natural sources include wheat germ, whole nuts, and seeds, and leafy green vegetables.
cereals, plant
the RDA for men and women (vitamin E);
RDA men (19-50): [..] mg
RDA women (19-50): [..] mg
15 mg x 2
because of vitamin E’s unique ability to be incorporated into cell [..] effectively, it acts within membranes as an [..], protecting cells throughout the body from the oxidative damage that results from exposure to [..] [..] produced in the body or present in the environment. it also helps prevent oxidative changes in low density lipoproteins (LDLs) that would otherwise increase LDL’s plaque forming potential; therefore, vitamin E may play a role in reducing [..] formation in blood vessels
membranes, antioxidant,
free radicals, plaque
vitamin E can break the chain of [..] by donating an [..] to free radicals without becoming unstable. because it is a fat soluble vitamin, it is particularly good at performing this function in cell [..] and even in lipoproteins such as [..]
oxidation, electron
membranes , LDLs
vitamin E appears to be of particular importance in maintaining healthy [..] function by protecting [..] blood cells from oxidative damage, particularly in aging [..]. adequate intake of vitamin E is also necessary to prevent damage to [..] tissue
immune , white
adults, nervous
vitamin E supplements (usually alpha-tocopherol) have not shown to [..] the risk of cancer or heart disease. however, other forms of vitamin E that are abundant in our diet may reduce our risk of cancer, cardiovascular, and neurodegenerative disease
reduce
diet
vitamin E is [more or less] likely to be toxic than either vitamin A or vitamin D and is only observed with very high intakes from supplements, which increase the tendency to [..]. because adverse effects have only been at very high levels, the UL for vitamin E (1000 mg, or 1500 IU) is set at more than 60 times the RDA
less, bleed
vitamin K is an essential nutrient that’s found in [..]
food
it was previously thought that vitamin K produced by bacteria in the [..] intestine contributed significantly to our daily needs, recent evidence indicates that we absorbed very little of the vitamin K produced there
large
the most significant dietary sources of vitamin K are green leafy [..]; some cheeses, fruits, and vegetable oils. the requirements of vitamin K are given in Adequate Intake (AI) amounts, because current knowledge does not provide sufficient evidence to establish a specific RDA.
vegetables
AI vitamin E for men and women;
AI men (19-50); [..] mcg
AI women (19-50); [..] [..] mcg
120 mcg
90
Vitamin K is required to complete the synthesis of several [..] in blood that cause the blood to [..] when those proteins are activated. also plays a key role in bone metabolism by modifying bone proteins, which allows them to bind calcium and regulate bone formation
proteins, clot
proteins
(insufficient evidence that vitamin K supplementation prevents osteoporosis or fractures)
given its key role in blood clotting, vitamin K deficiency can cause uncontrolled bleeding, or [..]. this can result from use of medications that prevent clotting (anticoagulants) and interfere with the metabolism of vitamin K.
hemorrhaging
newborn babies have received a dose of vitamin K at birth to reduce the risk of hemorrhage because they have limited liver stores of vitamin K and its content in breast milk is low
yes
there is no evidence that vitamin K is toxic at any level, and there is no established UL for vitamin K.
yes
some approaches to vitamin A deficiency provide only time [..] benefits. these include;
- the promotion of [..] breastfeeding, because breast milk contains higher amounts of vitamin A than many [..] foods that replace it in developing countries
- older children with vitamin A deficiency have been shown to benefit from periodic supplementation with high dose vitamin A, yielding substantial reductions in blindness, infection, and death
(long term approaches are needed aka golden rice)
limited
prolonged, alternative
gold rice is a long term approach, another is the creation of a biofortified orange fleshed sweet potato (OFSP), developed to ease vitamin A deficiency in many African countries. the OFSP naturally contains 50-fold higher levels of [..]-carotene than do paler strains
beta
overview; vitamin E serves as an important [..], surprising oxidation of [..] and lipids in cell membranes. vitamin E can break the chain of oxidation by [..] [..] through the donation of a(n) [..] without becoming unstable
antioxidant
free radicals
electron
overview of fat soluble diseases or issue by deficient;
vitamin D; [..] in children; [..] in adults
vitamin A; [..]
vitamin E; rare, but could lead to issues with [..] of lipids in cell membranes , and [.] cholesterol
vitamin K; uncontrolled [..]
rickets, osteomalacia
blindness
oxidation , LDL
bleeding
overview; the properties of fat soluble vitamins:
- stored in [..]
- absorbed in the [..] intestine and leave mucosal cells in [..]
- often found in [..] portion of foods
- tissue
- small, chylomicrons
- fatty
overview; sources of vitamin A
- provitamin A carotenoids found in plants can be converted to [..] in the body
- retinol activity equivalents (RAE) are a [..] of vitamin A activity
retinol
measure
overview; sources of vitamin D;
- [..] exposure on skin
- [..] liver oil
- milk and yogurt ([..])
- salmon
sun
cod, fortified, salmon
overview; antioxidants and free radicals;
- free radicals are formed during [..] metabolism in your body, from [..] light, and air [..]
- beta carotene can act as an [..]
- free radicals are necessary for cellular [..] and killing of [..]
- at high levels, free radicals cause [..] damage
energy, UV, pollution
antioxidant
communication, bacteria
oxidative
overview; vitamin D;
when blood calcium levels fall, vitamin D in the [..] is converted to [..] the fully active form of vitamin D .this fully active form of vitamin D increases the absorption of [..] in the [..] tract. it also works with parathyroid hormone to decrease [..] excretion by the [..], and to increase [..] release form bones to raise blood levels
kidneys , calcitriol
calcium, gastrointestinal, calcium , kidneys , calcium
overview; sources of beta carotene + retinol
- beta carotene; sweet potatoes, cantaloupe, and kale
- retinol; milk, salmon , eggs
yes
