deck_4503545 Flashcards

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1
Q

What are the 4 fat-soluble vitamins?

A

A, D, E, K

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2
Q

What do fat-soluble vitamins require for abspt?

A

Bile and dietary fat

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3
Q

How are these vitamins transported?

A

W/ fats through lymphatic system in chylomicrons

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4
Q

Are these vits stored? Where?

A

Yes, in body fat (adipose tissue)>Thus intake can vary w/o risk of deficiency

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5
Q

e. Not easily excreted, unlike water soluble vitaminsi. **Increase … ii. Ppl should not take supplements high in these vitamins

A

FIGURE OUT

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6
Q

What are pre-made/preformed vit A called? Is it active or inactive? Toxic?

A

Retinoids: retinol, retinal, retinoic acidActive (usable)May be toxic

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7
Q

Where are retinoids found?

A

Animal foods>Liver, eggs, fortified into dairy, fish

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8
Q

What is the provitamin/precursor form of Vit A)? Is it active or inactive? Toxic?

A

CarotenoidsInactiveNon-toxic

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9
Q

Where are carotenoids found?

A

Plants → Yellow, orange, red fruits and veggies>More color, more carotenoids• Frozen and canned > retail fresh»Carrots, red bell peppers, cantaloupe

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10
Q

What is Retinoid fxn?

A

> Key role in night vision>Cell differentiation (key in fetal development)>Growth regulation”needed for vision (retinal), and for growth and differentiation of cells (retinoic acid)”

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11
Q

What is Retinoic Acid used for?

A

used topically to treat certain skin conditions (e.g. acne)>Vit A is a key component>Helps cells divide more rapidly, clearing old cells

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12
Q

What is fxn of Carotenoids? How absorbed?

A

Family of Phytonutrients>Decrease cancer risk and prevent macular de-generation»>In eye, (yellow) carotenoids have been shown to decrease risk of macular degeneration>Need dietary fat to be absorbed (absorbed in chylomicron)

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13
Q

(???) How are preformed and precursor forms of Vit A transformed in digestive tract?

A

> Preformed → Retinol transformed into Retinal >Precursor → Beta-carotene transformed into Retinal in liverand intestinal mucosa&raquo_space;Retinal is converted to Retinoic Acid, can’t covert back

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14
Q

What is Vit A role in Visual Cycle?

A

> Vit A is a component of Rhodopsin (retinal + opsin) >When light hits, Retinal molecule changes molecular form»>Bent (cis) → straight (trans)»>Signals to brain that there’s light>Retinal breaks away from opsin → brain perceives light»>Retinal is lost in cycle»>Need more to form Rhodopsin»>If insufficient Retinal, eyes have difficulty adjusting to dark”- Retinal binds to opsin in the eye to form rhodopsin. After light strikes rhodopsin to begin the visual cycle, a nerve impulse is sent to the brain so the light is perceived.- When vit A is deficient, there is a delay in the regeneration of rhodpsin that causes difficulty seeing in dim light (night blindness).”

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15
Q

What is Vit A role in Gene Expression and Cell Differentiation ?

A

> Vit A has a role in directing which genes are transcribed and translated to create diff kinds of proteins»>Impt in early development and growth”- In order to affect gene expression, retinoic acid enters the nucleus of specific target cells, where it binds to retinoic acid receptor proteins; the retinoic acid-protein complex then binds to the regulatory region of DNA.”

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16
Q

What is relationship btwn Vit A and Keratin?

A

> Vit A helps w/ turnover of cells in eye that help w/ moisture and lubrication»>W/ insufficient Vit A, body creates Keratin, which leads to a hard and dry layer in the eye

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17
Q

Causes and symptoms of Vit A Deficiency?

A

Caused by insufficient intake of Vit A, fat>Night blindness>If severe: permanent blindness>Xerophathalmia – lack of mucous synthesis»>Keratin on the eye”More severe deficiency interferes w/ cell differentiation. This impairs immune fxn and growth and causes epithelial surface of eye to become hard and dry, leading to infection and blindness.”

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18
Q

Causes and symptoms fo Vit A Toxicity?

A

Retinoids – can be toxic and can increase risk of bone fractures and birth defects&raquo_space;>Supplements (including multivitamin) have Vitamin A in multivitamins has been related to hip fractures in postmenopausal womenCarotenoids – not toxic, but high intake can cause&raquo_space;>Hypercarotenemia: orange hue in skin, benign&raquo_space;>Birth defects

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19
Q

What are dietary and other sources of Vit D? Essential?

A

Vit D = “sunshine vitamin” → Produced in the skin by exposure to UV light>Not found in many foods, mostly eggs, fatty fish (salmon), and milk (fortified dairy products)>Only conditionally essential in diet if you’re not producing enough through skin

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20
Q

What is active form of Vit D?

A

Vit D3, or Cholecalciferol>Modified in liver and then activated in kidney

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21
Q

Vit D toxicity?

A

Toxic at high lvls>Flynn – toxicity not thought to be issue, even w/ supplementation, but widespread use of vit D as supplement is relatively newBook info:»>High blood and urine Ca2+ concentrations»>Depositing of Ca2+ in blood vessels and kidneys, cardiovascular damage and possibly death

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22
Q

Vit D fxns?

A

> Bone health → maintains lvls of Ca2+ and P in blood that favor bone mineralization w/ calcium phosphate>Normal fxning of parathyroid gland>Regulation of immune system

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23
Q

How is Vit D synthesized? Where is it activated?

A

Light causes 7-dehydrocholesterol to be converted to Vit D3 → Needs to be activated in liver and then kidney

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24
Q

Is dietary Vit D3 active or inactive?

A

Inactive

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25
Q

How does Vit D affect Ca2+ Abspt? PTH?

A

> Increases abspt of dietary Ca2+ through normalizing parathyroid gland>Vit D works w/ parathyroid hormone (PTH) to increase Ca2+ retention at kidney, increase release at the bone, and increase abspt at the intestine

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26
Q

Causes and symptoms of Vit D deficiency?

A

> Dietary Ca2+ can’t be absorbed efficiently>Improper bone mineralization>Abnormalities in bone structure>Cancer potential for all ages

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27
Q

Vit D deficiency in CHILDREN?

A

RICKETS=Bowed legs and abnormal ribs»>Has increased overtime bc children wearing more sunscreen and covered up

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28
Q

Vit D deficiency in ADULTS?

A

OSTEOMALACIA=Bone pain, muscle aches, increase in bone fractures

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29
Q

How does Vit E exist in food?

A

In 8 forms/isomers – we’re not able to absorb in all of those forms

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30
Q

What form of Vit E is the only form we can absorb and USE in the body?

A

Alpha-tocopherol

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31
Q

What is needed for Vit E to be absorbed and why?

A

FAT – bc packaged in chylomicron and then delivered throughout body

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32
Q

Why is Vit E requirement so high?

A

> Req is based on amount needed to maintain plasma concentrations of alpha-tocopherol that protect RBC membranes from rupturing>Requirement assumes vegetable oil intake»>Vit E is added to keep vegetable oils (high in polyunsat fats) from oxidizing

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33
Q

Causes and symptoms of Vit E deficiency in premature infants?

A

> Mother doesn’t transfer Vit E to fetus until 37weeks»>Can result in hemolytic anemia (rupture of RBCs)»>Same symptoms as iron and Vit B6 deficiency>Deficiency is rare bc vit E is plentiful in food supply and stored in many body tissues

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34
Q

What are some dietary sources of Vit E?

A

EVOO, Soybean oil, Nuts and seeds

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35
Q

What are some fxns of Vit E?

A

> Antioxidant»> Protects against cell damage by neutralizing free radicals that cause oxidative damage»>Neutralization Process: Vit E donates one of its e- to free radical → impairs further Vit E activity → Vit C can restore Vit E by replacing e-(replenishes its antioxidant potential)

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36
Q

Vit E in supplements vs in food?

A

> Supplement–no benefit, and some studies show Vit E supplements increase disease and hemorrhagic stroke risk>In food–not toxic»>Vegetable seed oils contain Vit E → used to decrease oxidation of oil

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37
Q

Benefits of Vit E in EVOO?

A

EVOO is highest in alpha tocophorol and monounsat fat >More Vit E available to body than in other veg oils bc its low in polyunsat fat

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38
Q

Primary fxn of Vit K?

A

Blood clotting (“Koagulation”/coagulation)

39
Q

1st form of Vit K? Dietary sources?

A

> Phylloquinone>Plants: Leafy greens (spinach, kale, broccoli)

40
Q

2nd form of Vit K? Dietary sources?

A

> Menaquinone >Animal foods (and synthesized by gut bacteria): Liver, salmon

41
Q

Symptoms of Vit K deficiency?

A

Rare>Major symptom: Abnormal blood coagulation»> Discovered when cattle were given fat-free diet, cows bleeding to death bc couldn’t absorb Vit K w/o fat»>Almost no Vit K is transferred from mother to fetus → newborns are routinely given Vit K injections at birth to prevent blood clotting disorders»>Very rare in US

42
Q

What is Vit K blood clotting process?

A

**Vit K is part of clotting cascade→Series of rxns involving clotting factors, several of which require Vit K for formation Vit K is coenzyme needed for produxn of prothrombin, other blood-clotting factors, and several proteins involved in bone formation and breakdown>Prothrombin (requires Vit K for its formation and subsequent conversion to Thrombin) → Thrombin → Fibrinogen (requires Thrombin for conversion to Fibrin) → Fibrin

43
Q

Vit K Toxicity

A

primarily a problem if you take supplements, less risk in diet- Bc vit K fxns in blood clotting, high doses can interfere w/ anticoagulant drugs, e.g. Coumadin

44
Q

What is Vit K impt for, excluding coagulation?

A

Bone health»>Used in laying down healthy, new bone»>Unlike other fat-soluble vitamins, the body uses vit K rapidly, so a constant supply is necessary

45
Q

What is relationship btwn Vit K and Coumadin?

A

> Coumadin (warfarin) =anticoagulation medicine>Vit K interferes (role in clotting)»>In past: patient told not to eat Vit K containing veggies»>Newer thought: Vit K containing veggies daily, adjust med to diet

46
Q

Why is too much clotting dangerous?

A

Risk of heart disease and strokeClots can break off and»>travel to brain → cause stroke»>travel to heart → cause heart attack

47
Q

How much of the blood is composed of water? Blood fxns?

A

90%-Transports O2 and nutrients to cells-Removes CO2 and waste products

48
Q

What are direct fxns of water in the body?

A

> Lubricant, cleanser, cushion against shock»>Tears: wash away dirt in eye»>Synovial fluid: lubricates joints»>Saliva: assists in chewing, tasting, swallowing»>Spinal fluid: protects again shock>Assists in regulating body temp (e.g. sweat)»>Can hold onto heat and changes body temp slowly>Part of metabolic rxns: we make water at end of ETC>Helps maintain acid-base balance

49
Q

Water deficiency (dehydration) vs. intoxication (overhydration)?

A

> Dehydration – thirst is a late signal>Intoxication – less common»>Can lead to hyponatremia (low sodium in blood), which can result in abnormal fluid accumulation in body tissues»>Marathon concern>If water intake is low, antidiuretic hormone will cause kidney to conserve water>If water intake is high, more water will be excreted in urine

50
Q

Our need for water is dependent on what 3 dietary factors? How?

A

> Protein, sodium, and fiber in diet»>higher consumption increases water needs>[Waste product from protein = urea]

51
Q

What are the 3 principle electrolytes?

A

Sodium (Na+), potassium (K+), chloride (Cl-)>Positively and negatively charges ions → conduct an electrical current in water

52
Q

What is distribution of principle electrolytes relative to cell?

A

[remember: 3Na out/2K in]>Na—main mineral OUTSIDE cell>K—main mineral INSIDE cell>Cl—exists w/ Na+ outside cell as salt, NaCl&raquo_space;>If eat a lot of sodium food (high Na+ outside of cell), you draw water out of cell = raises BP (pressure on heart)

53
Q

What are causes and symptoms of deficiency of Potassium?

A

> Usually caused by supplements or renal disease>”The electrolytes are found in plentiful amounts in the diet, and the kidneys of a healthy individual are efficient at regulating amounts in the body.”>”- Low levels can occur when water and electrolyte losses are increased due to excessive sweating, chronic diarrhea or vomiting, or kidney disorders.”

54
Q

Toxicity of K+?

A

> Caused by supplements>Leads to renal disease»>Can shut down heart

55
Q

Toxicity of Na+?

A

> Leads to high BP (hypertension/HTN)»>Rare (bc fluid usually compensates when you consume too much Na+)>Most of dietary sodium comes from packaged/ processed foods, not adding salt to food

56
Q

What is HTN? Dangers?

A

Increase in the pressure of the blood against the arterial walls (too much pressure on arteries)>No outward symptoms but can lead to heart and kidney diseases>Can damage arteries >Atherosclerosis >CVA → stroke

57
Q

Risk factors for HTN?

A

> Obesity>Aging>Diabetes – (bc insulin affects kidney)>Lack of physical activity>Poor diet (high Na+, low K+)>Genetics, ethnicity, smoking, heavy alcohol consumption, stress

58
Q

Treatment of HTN?

A

Conventional: decrease Na+ in diet**Main food sources of Na+ in diet: -Processed food-Packaged food (canned)-Fast food

59
Q

What is the DASH diet?

A

DASH=Dietary Approaches to Stop Hypertension**Increasing K+ intake by eating fruits and vegetables to lower BP

60
Q

What is 1 serving of fruits or vegetables?

A

1/2 cup

61
Q

How many servings of fruits and veg recommended for lowering BP?

A

9

62
Q

What would a typical day on DASH diet look like?

A

> Fruit at breakfast>Vegetables at lunch and dinner

63
Q

Definition of minerals

A

Nutrients needed by the body in small amounts for health and maintenance

64
Q

Sources of minerals?

A

unprocessed foods, some processed foods (fortified) and dietary supplements>Soil and water mineral concentration affects nutrition quality/content of some foods

65
Q

Why do some minerals have upper limits?

A

> Correct proportions of mineral intake is essential to health>ULs (upper limits) have been established for certain minerals due to toxicity, which often results from environmental pollution or excessive use of supplements

66
Q

What is bioavailability?

A

Amount of minerals in a food that is ABSORBED and AVAILABLE to the body

67
Q

What influences bioavailability?

A

Phytates, tannins, oxalates, and fiber ⇒Tend to be high in plant products>Minerals from plant foods are LESS available v. animal

68
Q

What are major sources of tannins? How do tannins affect bioavailability?

A

> Black tea and red wine>Hinder abspt of Ca++

69
Q

What are major sources of oxalates? How do oxalates affect bioavailability?

A

> Tree nuts, soy, chocolate>Bind Ca++

70
Q

How does fiber affect bioavailability?

A

Traps minerals

71
Q

How does body’s need of a mineral affect abspt?

A

The more deficient, the greater the abspt of that mineral

72
Q

What is mineral to mineral competition?

A

Calcium, magnesium, iron, and copper all complete for same transport mechanisms**This competition problem is w/ supplements

73
Q

What is fxn of minerals?

A

> Help regulate body processes, often as cofactors>Mineral cofactor combines w/ inactive enzyme to form active enzyme (???)[missed a lot → FIG]

74
Q

What is Calcium? Dietary sources?

A

> Most abundant mineral in body, 1-2% of adult body weight>Provides structure to bones and teeth and has impt regulatory roles>Dair, fish w/ bones, leafy green veggies, fortified foods

75
Q

How is Ca2+ absorbed?

A

> Passive diffusion → need high concentration gradient of Ca2+>Active trnspt → W/o gradient, active form of Vit D is critical to help transfer Ca2+ across cell membranes>abspt is highest pre-puberty

76
Q

What factors increase and decrease bioavailability of Ca2+?

A

Increase—presence of vitamin D, acidic foods, lactose, and fat Decrease—iron, tannins, fiber, phytates, and oxalates

77
Q

What is role of Ca2+ in the body?

A

> 99% is found in solid mineral deposits in the bones and teeth»>Pre-puberty is time of greatest Ca2+ deposition>Remaining 1% is found in intracellular fluid, blood, and extracellular fluid»>Role in cell communication, nerve transmission, mscl contractions, blood pressure regulation and release of hormones

78
Q

What is osteoporosis? Reversible?

A

a condition in which loss of bone mass increases the risk of bone fractures>Loss of bone (protein and mineral content)>Not reversible

79
Q

Risks factors for osteoporosis?

A
  • risk is related to lvl of peak bone mass and rate of bone loss>older age>gender (women greater)>diet»>Ca2+ is main mineral in bone, but no data showing that intake after pre-puberty will prevent or treat osteo>low physical activity
80
Q

What factors increase Ca2+ loss in urine?

A

> Meat/poultry/seafood metabolism>High sodium intake (???)>Low plant product intake (K+ in diet prevents loss)

81
Q

Problems w/ Ca2+ Supplements

A

Flynn: usefulness is questionable>Has been related to kidney stones in women (17% increase in risk)>Blocks abspt of other minerals: iron, magnesium, copper

82
Q

What is Phosphorus (P)? Component in body?

A

> Makes up about 1% of an adult’s body»>85% of P in body is found in bones and teeth>More readily absorbed than Ca2+>Impt component of molecules w/ structural or regulatory roles

83
Q

Symptoms of phosphorus deficiency?

A

Bone loss, weakness, and loss of appetite>Rare bc it’s abundant in most foods and more easily absorbed than other minerals

84
Q

Phosphorus toxicity?

A

Toxicity thought to be rare, can lead to bone reabspt>Daily cola (high intake of soda) = increase in bone fractures in adolescent girls, hip fractures in post-menopausal women

85
Q

What is Magnesium (Mg)? Component in body?

A

> 50-60% in the body is found in bone»>Essential for maintenance of structure>Present inside cells, where it’s 2nd most abundant intracellular ion, after K+>Cofactor for over 300 enzymes»>Metabolism of energy-yielding nutrients>affects metabolism of calcium, sodium, and potassium

86
Q

Dietary sources of Mg?

A

> Component of chlorophyll»>Leafy greens, nuts, seeds, bran

87
Q

What are risk factors for Mg deficiency?

A

Deficiency is rare, but risk is high w/ high alcohol consumption or general malnourishment

88
Q

What are symptoms of Mg deficiency?

A

-Nausea-Mscl weakness and cramping-Mental derangement -Changes in BP and heartbeat

89
Q

What is Mg toxicity?

A

Rare>No adverse effects have been observed from food>Some toxicity from supplements observed, esp among elderly»>UL for adults has been set at 350mg from nonfood sources

90
Q

What are sources of sulfur? Recommended daily intake?

A

> Protein-containing foods and sulfur-containing AAs in vitamins (THYMINE, BIOTIN) >Nonfood additives, e.g. sulfur dioxide, sodium sulfite, and sodium bisulfite>No recommended daily intake

91
Q

What is sulfur’s role in body?

A

Sulfur-containing AAs, such as methionine and cysteine, are needed for protein synthesis>need in energy metabolism and in the regulation of the pH balance

92
Q

Cause and symptoms of Ca2+ deficiency?

A

> Low intake or high loss in urine >Normal blood lvls are maintained by resorbing Ca2+ from bone, resulting in Ca2+ loss from bone- Deficiency can reduce bone mass and increase risk of osteoporosis

93
Q

Symptoms of excessive Ca2+?

A

Kidney stones, constipation, raise blood Ca2+ lvls, interfere w/ abst of other minerals, like iron