Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology 2 > KIN 346Module 3 > Flashcards

KIN 346Module 3 Flashcards

1
Q

What are vitamins?

A

Essential, organic micronutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How do vitamins differ from macronutrients?

A

1) Structure: found in individual units 2) Function: don’t yield energy 3) Food contents: amounts ingested and required are usually measured in micrograms and milligrams

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What affects bioavailability of vitamins?

A

1) efficiency of digestion and previous nutrient intake 2) method of preparation (some are easily destroyed) 3) source of the nutrient (supplement, food, fortification) 4) Other foods consumed at the same time (may help or hunder)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are precursors or previtamins?

A

Inactive form of vitamins that must be activated in the body to be useful

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the fat soluble vitamins?

A

A,D,E,K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the water soluble vitamins?

A

The Bs and Vitamin C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How are fat soluble vitamins absorbed?

A

into lymph, requires bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How are fat soluble vitamins transported?

A

require protein carriers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How are fat soluble vitamins stored?

A

in fat compartments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How are fat soluble vitamins excreted?

A

tend to be stored

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Are fat soluble vitamins toxic?

A

More likely than water soluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the requirements for fat soluble vitamins?

A

periodic doses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How are water soluble vitamins absorbed?

A

directly into the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How are water soluble vitamins transported?

A

travel freely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How are water soluble vitamins stored?

A

in water compartments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How are water soluble vitamins excreted?

A

usually excess is removed in urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Are water soluble vitamins toxic?

A

Less likely, but possible from supplements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the requirements for vitamins?

A

frequent doses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the RDAs for Vitamin A for men and for women?

A

Men (19-30): 900 micrograms/ day. Women (19-30) = 700 micrograms per day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Three active forms of reinoids in the body?

A

Retinol, retinal, and retinoic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How is vitamin A absorbed and where is it stored?

A

Absorbed into the lymph and stored in the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Animal foods supply what form a vitamin A?

A

Supply retinyl esters, absorbed as retinol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Food sources of retinol/retinyl esters?

A

liver, fish oils, eggs, milk, milk products, and fortified foods such as margarine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Plan foods supply what type of Vitamin A?

A

Carotenoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Food sources of carotenoids?

A

Leaft greens (kale, spinach), and orange veggies and some orange fruits (squash, sweet potato, cantaloupe, apricots, and papaya)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are cartenoids?

A

Orange pigments found in foods in which some have vitamin A activity (called prescursors)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What carentoid has the highest vitamin A activity?

A

Beta-carotene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does beta carotene consist of?

A

Two molecules of retinol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

12 micrograms of beta-carotene = ?

A

1 microgram vitamin A (retinol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How is vitamin A activity measured?

A

Retinol Activity Equivalents (accounts for active forms and precursors)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is an important role of Vitamin A?

A

regulation of gene expression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is an important role of retinal?

A

promoting vision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is an important role of retinoic acid?

A

Protein synthesis and cell differentiation (maintenance of epithelial tissues) and growth (bone remodelling)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Important role of retinol?

A

Supports reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Important role of beta carotene?

A

acts as anantioxidant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the two indispensable roles of vitamin A in vision?

A

maintenance of the cornea and conversion of light energy into nerve impulses in the retine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Steps in vision?

A

Retina contains rhodopsin, a molecule composed of opsin (a protein) and cis-retinal (vitamin A). Light hits rhodopsin and retinal becomes trans-retinal, causing it to detach from opsin, sending nerve impulses to the brain to cause vision.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How does vitamin A deficiency cause blindness?

A

When trans-retinal is being converted back into cis-retinal, some of it is oxidized to retinoic acid, which cannot be turned back into retinal, so more retinal is needed either directly or from converting retinol to retinal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does vitamin A adequacy depend on?

A

stores (liver) and protein status

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Where is vitamin A mainly stored?

A

The liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are the 2 stages of blindness caused by vitamin A deficiency?

A

Night blindness (retina) and progressive blindess called xeropthalmia (cornea)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is keratinization, and deficiency in what vitamin causes it?

A

The hardening and thickening of skin. Faltering of digestion and absorption. Weakened defenses because of weakened epithelial tissue. Caused by a vitamin A deficiency.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Why do WHO and UNICEF recommend routine vitamin A supplementation?

A

Severity of measles often correlated with degree of deficiency, and a deficiency in vitamin A increases vulnerability to infectious disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

UL for vitamin A?

A

3000 micrograms/d of PREFORMED vitamin A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Consumption of what increases the risk of vitamin A toxicity?

A

Eating lots of liver, supplements, and fortified foods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Free vitamin A damages the tissues when?

A

Binding proteins are swamped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What characterizes vitamin A toxicity?

A

Over-stimulated cell-division (bone abnormalmities (weakening), birth defects (teratogen), liver failure, and death)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Excess beta carotene intake from foods?

A

high intake from foods is harmless…causes yellowing if the skin (not eyes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Excess beta-carotene from supplements causes?

A

Problematic. Toxic levels can be reached by overriding body’s usual protective mechanisms, can become pro-oxidant, destroys Vitamin A in cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Other name for Vitamin D?

A

Calciferol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

RDA for vitamin D for males (19-30) and females?

A

15 micrograms/day for males and females (600IU)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is the active form of vitamin D?

A

1,25-dihydroxycholecalciferol (calcitriol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Why is vitamin D considered non-essential or “conditionally essential?”

A

It can be synthesized endgenously from the precursor 7-dehydrocholesterol, made in the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What are some animal foods that supply vitamin D?

A

egg yolks, liver, fatty fish and their oils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What type of vitamin D do animal foods supply?

A

cholecalciferol (vitamin D3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What type of vitamin D do plant foods supply? Are there good sources of this?

A

Supply ergocalciferol (vitamin D2), and no good sources exist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are some fortified foods that are a source of vitamin D?

A

milk and margarine (mandatory), butter, juices, cereals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Steps in vitamin D synthesis and activation

A

1) 7-dehydrocholesterol (a precursor made in the liver from cholesterol) in the skin gets hit with UV light 2) Forms previtamin D3 or Vitamin D3 comes from foods (inactive form) 3) In the liver, hydroxylation turns it in 25-hydroxy vitamin D3 (calcidiol) 4) Hydroxylation in the kidneys turns it into the active form, 1,25-dihydroxy Vitamin D3/calcitriol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

How many hydroxylations must occur to get active vitamin D3, and where do they occur?

A

2, in the liver and the kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Active form of vitamin D3 is a ___

A

hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

How does vitamin D participate in bone growth and maintenance?

A

By maintaining concentrations of calcium and phosphorus through action at the intestine, kidneys, and bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

How does vitamin D maintain blood concentrations of phosphorus and calcium through the intestine, kidneys, and bone?

A

Intestine: increases absorption when diet is adequate. Kidneys: increases REabsorption with parathyroid hormone. Bone: increases mobilzation with parathyroid hormone. Many other roles are being studied.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Vitamin D is needed to produce a protein that binds calcium in intestinal cells, what is this protein called, and what does vitamin D deficiency cause with respect to it?

A

Calbindin, deficiency means that dietary calcium absorption is limited. This creates a secondary deficiency that leads to bone abnormalities such as rickets in childrem, osteomalacia in adults, and increased risk of osteoporosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What are some reasons why people become vitamin d deficient from lack of sunshine?

A

older age, northern latitude, pollution, sunscreen, clothing, skin pigmentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Percentage of Canadians that are vitamin D deficient in winter and summer?

A

40%, 25%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

For all Canadians, what is recommended to guarantee vitamin D requirement is met?

A

2 cups of fortified milk daily…supplements for older adults, as well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is the UL for vitamin D?

A

100 micrograms/day (4000 IU)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is vitamin D toxicity usually due to?

A

Excess supplementation. Dietary excess from food sources is unlikely. Endogneous production from sunlight cannot reach toxic levels–precursors in skin are degraded with long sun exposure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What does vitamin D toxicity cause?

A

Elevated blood concentration (hypercalcemia) leading to calcification of soft tissues (kidney stones and calcification of blood vessels)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is another name for Vitamin E?

A

Tocopherol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

RDA for 19-30 males and females for vitamin E?

A

15 mg/day…those with high PUFA intakes may need more

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Why do people with high PUFA intakes need more vitamin E?

A

Vitamin E is an antioxidant that prevents the oxidation of PUFAs, so more in your diet, the more protection you need from oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

How many tocopherol compounds are there, what is hthe biologically active form?

A

4 different forms differentieated by positions of their methyl groups. Alpha-tocopherol is the biologically active form, other forms cannot be converted to alpha-tocopherol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Is vitamin E widespread in the food supply?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What are the main sources of vitamin E in the food supply?

A

Vegetale oils and products made from them (margarine, salad dressings)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What are some food sources of vitamin E in food?

A

vegetable oils and products made from them, wheat germ (ground), whole grains, nuts and seeds, liver, egg yolkd, leafy green vegetables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Is vitamin E easily destroyed?

A

YES! by heating process (deep fried foods)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What are the roles of vitamin E?

A

ANtioxidant (prevents oxidation of PUFAs and other lipids and protects cell membranes from oxidative damage), and may protect against heart disease by protecting LDL against oxidation and reducing inlfammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Where is vitamin E deficiency primarily seen?

A

premature infants (transfer of vitamin E in last few weeks of pregnancy) and in conditions of fat malabsoprtion (CF, Chron’s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What is the acute effect of vitamin E deficiency?

A

Hemolytic anemia (RBC explode becaues loss of PUFAs in membrane)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What is the long term effect of vitamin E deficiency?

A

Causes neuromuscular dysfunction (loss of muscle coordination and relfexes, impaired vision and speech)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

UL of vitamin E?

A

1000 mg/day…can’t achieve through foods alone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Why is vitamin E toxicity rare?

A

blood concentration is tightly regulated by the liver.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What do extreme intakes of vitamin E cause?

A

Hemorrhage because it interferes with clotting action of vitamin K and enhances the action of anti-clotting drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

AI for vitamin k for males and females?

A

120 micrograms/d and 90 micrograms/day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

Where does about 50% of our vitamin K intake come from?

A

Synthesized endogenously by GI bacteria as a product of fermentation, the rest must be suppled from dietary sources (i.e. it remains essential)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

Is vitamin K essential?

A

YES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Where is vitamin K stored?

A

The liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What does animal food supply in terms of vitamin K, and what foods supply it?

A

Supply menaquinone…liver and milk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What do plant food supply in terms of vitamin K, and what foods supply it?

A

Supply phylloquinone…leafy green vegetables, cabbage-type vegetables (brussel sprouts, brocolli, and cauliflower), vegetable oils (canola and soybean)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Roles of Vitamin K

A

involved in the cascade of reactions that lead to blood clotting *required to repair damage to blood vessels and tissues). Participates in bone health (metabolism of osteocalcin to actiavte carboxylase, decreases bone turnover, protects against fracture)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

What is osteocalcin?

A

A bone proten that binds calcium to bone…helps activate carboxylase, which is needed to bind the calcium. Protects against fracture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

Although primary vitamin K deficiency is rare, when can it happen, and what does it cause?

A

Can be found in conditions of fat malabsorption, newborn infants and those on antibiotics. Causes poor wound healing and hemorrhage/

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

What are the water soluble vitamins?

A

B family and C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

Another name for vitamin C

A

ascorbic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

Vitamin C requirements?

A

90 mg/day for males, 75 mg/d females

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

Why do smokers require an extra 35 mg/d of vitamin C?

A

Lots of oxidation takes place, so extra vitamin c is needed for more antioxidants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

What are some sources of vitamin C?

A

citrus, strawberries, bell peppers…fruits and veggies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

How is vitamin C easily destroyed?

A

Heat (cooking) and oxygen exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

How much vitamin C does one cup of orange juice provide?

A

> 100 mg (more than the RDA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

Roles of vitamin C

A

Works as antioxidant because it can easily donate electrons to unstable free radicals (can be restored to its active form by accepting an electron, key to limiting losses and maintaining antioxidant reserve, in the SI, it protects Fe from oxidation, enhancing absoprtion). Cofactor in the formation and maintenance of collagen (connective tissue serving as a matrix on which bones and teeth are fored, involved in wound healing). Cofactor in the synthesis of a number of compounds (carnitine, NTs, thyroxin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

What does vitamin c deficiency cause?

A

Loss of integrity of blood vessels causes bleeding (scorbutic) gums, pinpoint hemorrhages. Long-term inadequacy leads to scurvy (hemorrhage, dry and rough skin, impaired wound healing, bone abnormalities, anemia and infection, sudden death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

UL for vitamin c?

A

2000 mg/d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

What can vitamin c toxicity result from?

A

overzealous supplementation (often for the common cold)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

Symptoms of vitamin c toxicity?

A

GI distress, diarrhea, can interfer with anticlotting medications, causes kidney stones, can become a pro-oxidant and contribute to Fe overload (increases absorption of Fe in GI tract and increaes release of Fe from iron stores)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

Can vitamin C cure the common cold?

A

No. Modest, consistent reduction in duration and severity and reduced risk after periods of physical stress, though.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

As a group, what do the B vitamins do?

A

Work as coenzymes in energy metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

What are the B family vitamins?

A

Thiamin, riboflavin, niacin, folate, pyridoxine, cobalamin, biotin, pantothenic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

As a group, what are common signs of vitamin B deficiencies?

A

Glossitis (shiny tongue from it being swollen) and Cheilosis (corners of mouth become cracked)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

RDA for Thiamin for men and women?

A

1.2 mg/d an 1.1 mg/day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

What is thiamin?

A

vitamin B1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

What is thiamin deficiency a result of?

A

A result of malnourishment (diet less than 1200 cals, homeless, poor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

What does prolonged thiamin inadequacy result in?

A

Beriberi (dry = damage to nervous system, muscle wasting, wet = damage to cardiovascular system - edema)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

What is Wernicke-Korsakoff syndrome?

A

Thiamin deficiency in alcoholics…disorientation, memory loss, jerky eye movements, staggering gait

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

What is the upper limit for thiamin?

A

Toxicity is not observed, so no UL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

What is riboflavin?

A

Vitamin B2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

RDA of riboflavin for men and women?

A

1.3 mg/d for men, 1.1 mg/day for women

118
Q

Role of riboflavin?

A

Coenzyme in a number of reactions, including energy metabolism as flavin mononuleotide (FMN) and flavin adenine dinucleotide (FAD), accept and donate hydrogen

119
Q

Sources of riboflavin?

A

mostly milk products, liver, also whole and enriched grains

120
Q

Why is milk packaged in a certain way in regards to riboflavin?

A

To avoid its destruction by UV light and irradiation

121
Q

Riboflavin deficiency is known as? What does it cause?

A

Ariboflavinosis…inflammation of membranes (mouth, skin, eyes, GI tract), glossitis and cheilosis

122
Q

UL for riboflavin?

A

Toxicity is not observed, no UL

123
Q

What is niacin?

A

Vitamin B3

124
Q

RDA for niacin?

A

16 mg NE/ d for men, 14 mg NE/d women

125
Q

How can niacin be produced endogenously?

A

Using the AA tryptophan…60 mg of tryptophan is needed to produce 1 mg niacin…requirements are expressed in niacin equivalents (NE)

126
Q

What are the two forms of niacin? Where are they found?

A

Nicotinic acid (synthetic) and nicotinamide (major form in blood)

127
Q

Roles of niacin?

A

involved in energy transfer reactions as coenzymes nicotinamide adenine dinucleotide and its phosphate form (NADP). Protects against neurological degeneration. High doses of nicotonic acid may produce a pharmacological effect (raise HDL and lower LDL)

128
Q

Sources of Niacin?

A

milk, eggs, legumes, enriched and whole grains, all protein containing foods (supply tryptophan)

129
Q

Why was niacin deficiency prevalent in the southern US? How was it fixed?

A

Due to reliance on low protein, corn-based diets, which are low in tryptophan and niacin. Greater than 70% of niacin in corn is bound to complex CHO and small peptides high in leucine. Treatment with LIME increases bioavailability.

130
Q

What is niacin deficiency known as, and what is it characterized by?

A

Pellagra, the four Ds…diarrhea, dermatitis, dementia, death

131
Q

UL for niacin toxicity?

A

Nicotinic acid (synthetic)

132
Q

Does naturally occurring nicotinamide cause toxicity?

A

Nope

133
Q

How does excess niacin intake occur, and what does it cause?

A

Excess intake from supplements (energy drinks) results in niacin flush (dilation of capillaries leading to tingling sensation, painful flushing of skin, rash)

134
Q

RDA for folate for men and women?

A

400 micrograms per day for men and women. Needs increase during pregnancy

135
Q

Two forms of folate?

A

Naturally occurring folacin, and Synthetic folic acid.

136
Q

requirements for folate are expressed in?

A

dietary folate equivalents, accounting for differences in bioavailability

137
Q

Which form of folate is more bioavailable?

A

Synthetic form (folic acid) is 1.7x more bioavailable

138
Q

Roles of folate

A

Transfer of 1-C compounds arising during metabolism, involved in synthesis of DNA, conversion of B12 to one of its coenzyme forms

139
Q

Sources of folate?

A

Leafy green vegetables, legumes, seeds, liver, and enriched grains

140
Q

Two types of folate deficiency?

A

Primary (inadequate intakes) or secondary (impaired absorption, unusual metabolic need)…higher amounts are needed for times of rapid cell division (pregnancy). Adequate intake before and during pregnancy prevents neural tube defects.

141
Q

Folate deficiency causes?

A

Impaired cell division and protein synthesis…replacement of RBCs and GI tract cells falters, leads to megaloblastic anemis, and glossitis

142
Q

What is megaloblastic anemia?

A

Large, immature RBCs

143
Q

When did folate fortification of grains become mandatory, and by how much did neural tube defects decrease?

A

1998, 46%

144
Q

UL for folate?

A

1000 micrograms/day (fortified foods and supplements). Naturally occurring folate is not harmful, but supplements and fortified foods can lead to excess

145
Q

What is the main concern of folate toxicity?

A

Masks a B12 deficiency symptoms…both folate and B12 deficiencies cause megaloblastic anemia, supplementing with folate will cure the anemia but not the other symptoms of B12 deficiency

146
Q

What is cobalamin?

A

B12

147
Q

RDA for cobalamin?

A

2.4 micrograms/day

148
Q

Roles of cobalamin?

A

Coenzyme in methyl transfer reactions in metabolism, maintenance of the myelin sheath protecting nerve cells, conversion of folate to one of its coenzyme forms, involved in synthesis of DNA, regenerates methionine from homocysteine

149
Q

What is homocysteine?

A

AA occurring naturally in blood and high levels increase the risk of CVD

150
Q

Sources of vitamin B12?

A

almost exclusively in animal foods, with greatest bioavailability from milk and fish. Vegans must seek out fortified foods (soy beverage)

151
Q

Digestion and absorption of cobalamin?

A

Stomach: HCl and pepsin release B12 from proteins Stomach to small intestine: B12 binds with stomach secretion called intrinsic factor End of small intestine: recognizes complex and is absorbed

152
Q

What is required for cobalamin to be absorbed?

A

Intrinsic factor

153
Q

Why is primary B12 deficiency rare?

A

It enters the enterohepatic circulation, so it is recycled like bile…take about 3 years to deplete your B12, possible in vegans

154
Q

What are most B12 deficiencies from, and what do they cause?

A

Most are due to inadequate absorption…lack of HCl or intrinsic factor or atrophic gastritis in those >50 years old. Supplements must bypass the stomach or be enteric coated. Causes pernicious anemia (megaloblastic) and neerve damage

155
Q

What 2 vitamins cause megaloblastic anemia when deficient?

A

Folate toxicity and B12 deficiency

156
Q

What is atrophic gastritis?

A

a process of chronic inflammation of the stomach mucosa, leading to loss of gastric glandular cells and their eventual replacement by intestinal and fibrous tissues. As a result, the stomach’s secretion of essential substances such as hydrochloric acid, pepsin, and intrinsic factor is impaired, leading to digestive problems, vitamin B12 deficiency, leading to megaloblastic anemia or malabsorbtion of iron, leading to iron deficiency anaemia

157
Q

What are minerals?

A

Naturally occurring inorganic elements (micronutrients)

158
Q

Structure, function, and food contents of minerals?

A

Found as elements, retain chemical structure. Do not yield energy. Amounts ingested and required are usually measured in micorgrams to grams

159
Q

Requirements of minerals are affected by?

A

Bioavailability…efficiency of absorption and previous nutrient intake, sources of the nutrient, other foods sunsumed at same time (may help of hinder)

160
Q

4 classes of minerals

A

major, trace, electrolytes, ultratrace

161
Q

RDA for iron?

A

men = 8 mg/d. Women = 18 mg/d

162
Q

How is iron transported in the blood?

A

Attached to the protein transferrin

163
Q

Where and how is iron usually stored?

A

Primarily stored in the liver, attached to the protein ferritin and excess is stored as hemosiderin

164
Q

Roles of iron?

A

Accepts, carries and releases oxygen (bound to Hb and myoglobin), cofactor in oxidation-reduction reactions be swtiching between its oxidized (Fe3+) ferric form and reduced (Fe2+) ferrous form. Forms part of the e- carriers in the ETC

165
Q

Usual diet supples about how many mg of iron per 1000 kcal?

A

6-7 mg

166
Q

Animals food supply what type of iron?

A

Heme and non-heme iron

167
Q

What type of iron is best absorbed? Where is it found?

A

heme iron, found ONLY in animal foods

168
Q

Sources of heme iron?

A

red meat, fish, poultry, eggs, clam, liver

169
Q

Plant foods supply what type of iron?

A

Non-heme iron

170
Q

Sources of non-heme iron?

A

legumes, whole and enriched grains, dried fruit

171
Q

What type of iron is the greatest in our diets?

A

Non-heme iron (90%), heme (10%)

172
Q

How is iron absorption regulated?

A

In times of need, iron absoprtion is enhanced. When stpres are full, absorption is reduced.

173
Q

Enhancers of NON-HEME iron absorption?

A

MFP factor (meat, poultry, fish peptide) and vitamin C (prevents oxidation of iron)

174
Q

Inhibitors of NON-HEME iron absorption?

A

Phytates (legumes and grains), vegetable proteins (legumes, nuts), calcium, tannic acid (tea, coffee), excess Zn

175
Q

How is iron recycled?

A

Most of the iron attached to transferrin goes to bone marrow to be incorporated into Hb of RBC and excess iron is stored in ferritin and hemosiderin. Spleen then dismantles RBC (after about 4 months), packages Fe into transferrin and stores excess iron in ferritin and hemosiderin/

176
Q

What is the most prevalent dietary deficiency in the world?

A

Iron

177
Q

Populations most vulnerable to iron deficiency?

A

women in reproductive years (blood losses), pregnant women (increased blood volume, growth, losses in birth), infants and young children (high milk diets and rpaid growth), adolescents (rapid grwoth, typically poor diet quality), vegetarians (consuming only non-heme Fe, needs are 1.8x higher)

178
Q

Stages of iron deficiency?

A
  1. Diminishing stores (low serum ferritin) 2. Decreasing transport iron (low serum iron + increase in transferrin = decreased transferrin saturation) 3. Limited hemoglobin production (low Hb and hematocrit). Over time, severe depletion results in iron deficiency anemia (RBCs are small (microcytic) and pale (hypochromic)
179
Q

Signs of iron deficiency anemia?

A

Weakness and fatigue, pallor, cold sensitivity, pica, and koionychia

180
Q

What is pica, and when is it common?

A

Desire to eat non-food things…iron deficiency

181
Q

What is koilonychia, and when is it common?

A

Spoon shaped nails…very advanced iron deficiency

182
Q

UL of iron?

A

45 mg/d…in general, diet poses no risk because the body absorbs less when stores are full, high risk from supplement intake

183
Q

What is hemachromatosis?

A

Genetic disorder, common in men when the body continues to absorb iron even when stores are full. Leads to hemosiderosis and free radical damage

184
Q

RDA for calcium, established in 2010

A

1000 mg/d for males and females. Higher in adolescents and older adults/

185
Q

What aids calcium absorption?

A

Aided by the stomach’s acidity and requires calcium binding protein (calbindin, which needs vitamin D)

186
Q

Calcium absorption is inhibited by?

A

Lack of stomach acid and vitamin D, high P intake, phytates and oxalates

187
Q

In a usual diet, how much of dietary Ca is absorbed?

A

about 30%

188
Q

What are the single highest source of Ca?

A

Milk products

189
Q

1 food guide serving of milk products has how many mg of Ca?

A

300

190
Q

Other sources of calcium besides milk products?

A

calcium set tofu, fish with bones, nuts

191
Q

Roles of calcium

A

99% is found in the bones and teeth (integral part of bones structures and serves as a calcium bank in times of need). 1% is found in intra and extracellular fluids (involved in maintenance of BP, participiates in blood clotting, regulation of muscle contraction, transmission of nerve impulses). May protect against hypertension and overweight

192
Q

How are blood calcium levels kept stable, and at what 3 sites?

A

By the action of vitamin D, parathyroid hormone, and calcitonin at the kidneys, intestines, and bones.

193
Q

Rising blood calcium causes…

A

Thyroid secretes calcitonin, inhibits the activation of vitamin D, limits Ca absorption from GI, prevents Ca reabsoprtion in kidneys, and inhibits release of Ca from bones. Result = lower blood Ca which inhibts secretion of calcitonin

194
Q

Falling blood calcium causes…

A

Parathyroid secretes parathyroid horomone, stimulates the activation of vit D. Vitamin D + PTH = stimulates Ca reabsorption at kidneys, enhance Ca absorption from GI, stimulates release of Ca from bones. Result = higher blood Ca which inhibits secretion of PTH

195
Q

High blood Ca results in? Low blood Ca results in? Are these related to dietary deficiency or excess?

A

Calcium rigour. Calcium tetany. Not related to diet.

196
Q

Inadequate intakes of calcium result in?

A

bone loss. This is generally not apparent until there are drastic consequenes such as osteoporsis…detected by measuring bone mineral density via DEXA

197
Q

What is the UL for calcium?

A

2500 mg/d

198
Q

Supplements and abnormal secretion of regulatory hormones can cause hypercalcemia, what are the signs of this?

A

constipation, risk of urinary stones and kidney dysfunction, calcification of soft tiddues, and it interferes with absorption of other minerals, notably Fe.

199
Q

What is the AI for sodiuM?

A

1500 mg/d

200
Q

The AI for sodium is set at 1500 mg/d, although, the body needs much less to function. Why is it set this high?

A

In order to still be able to maintain adequate intake of other nutrients…low enough to ward off hypertension, though

201
Q

How is sodium absorbed, and how does it travel in the bloodstream?

A

Readily absorbed in the intestine and travels freely in the bloodstream

202
Q

What maintains blood sodium concentrations?

A

The kidney by filtering Na from the blood…excess is excreted, required Na is returned to the bloodstream

203
Q

Roles of sodium

A

Regulates fluid volume as the principle cation in the extracellular fluid (water follows sodium in the body; high Na in the blood leads to thirst–excess Na is excreted with water). Participates in maintaining acid–base balance (kidneys excrete H+ ions in exchange for Na+ ions, increasing pH). Needed for nerve impulse transmission and muscle contraction

204
Q

% of sodium that comes from veggies, meats, and milk products?

A

about 10%

205
Q

% of foods that come from processed foods

A

accounts for up to 75% of dietary sodium

206
Q

% of sodium that comes from being added at the table

A

about 25%

207
Q

3 sources of sodium

A

veggies/meat/milk produts, processed foods, added at the table

208
Q

Main source of sodium in the diet?

A

Processed foods

209
Q

1 tsp/5 ml of NaCl = g NaCl = mg NaCl

A

1 tsp = 6 g = 2300 mg Na

210
Q

Top 5 sources of Na in the Canadian diet

A

1) breads and bread like things 2) processed foods 3) vegetable based dishes 4) soups 5) pasta

211
Q

What effect does food processing have on sodium and potassium?

A

Increases sodium whilst decreasing potassium

212
Q

UL for sodium?

A

2300 mg/d

213
Q

Acute sodium toxicity results in?

A

Edema and high blood pressure, however, the greatest concern is long-term excess

214
Q

What is the main health concern of NaCl intake?

A

Hypertension (especially in salt responders)…contributes to renal disease, cardiovascular disease, stroke, myocardial infarction. Associated with urinary Ca loss, stomach cancer

215
Q

Mean intake of sodium for Canadians

A

3400 mg…although, people are concerned about it

216
Q

Barriers to reduced intake include:

A

lack of options, taste, lack of knowledge

217
Q

Diets low in K cause what?

A

Play a role in the development of hypertension, especially when combined with high Na intake…intakes among Canadians tend to be low

218
Q

What is the DASH diet?

A

Dietary Approaches to Stop Hypertension…emphasizes fruit, vegetables. low fat milk products. Includes whole grains, nuts, poultry, and fish. Low in red meat, butter, high fat foods.

219
Q

Personal recommendations for lowering sodium intake?

A

select fresh foods (shop perimeter of the store), add little to no salt in cooking (use herbs and spice for flavour), read labels carefully (choose sodium free or low sodium, not neceaarily reduced)

220
Q

%DV of sodium reflects a comparison to what number?

A

2400 mg (>UL of 2300 mg)

221
Q

How can free radicals can cause damage to body cells?

A

Attacking lipids in cell membranes and lipoproteins. ALtering DNA, RNA and body proteins

222
Q

What is oxidative stress?

A

When production of oxidants and free radicals exceeds the body’s ability to defend against them and prevent widespread damage

223
Q

Oxidative stress causes?

A

decreased cognitive performance, premature aging and most chronic disease (cancer, diabetes, CVD)

224
Q

First line of defense against free radicals is? The second line of defense?

A

First line is a system of enxymes that disarms the most harmful oxidants (depends on the minerals selenium, copper, manganese and zinc. Link of defense weakens when one’s diet is inadequate). The second line of defense is antioxidant vitamins (vitamin E, beta-carotene, vitamin C. SOme phytochemicals also have antioxidant properties)

225
Q

Ways dietary antixodants protect against oxidative stress?

A

limiting the formation of free radicals, destroying free radicals or their precursors, stimulating antioxidant and repair enzyme activity, repairing oxidative damage, supporting a healthy immune system. Antioxidant vitamins tend to be stable in both their oxidized and reduced forms–can stop the free radical chain reaction

226
Q

What are phytochemicals?

A

non-nutritive compounds in plants that have biological activity that is beneficial to health.

227
Q

Roles of phytochemicals in the body?

A

acting as antioxidants, mimicking hormones, stimulating enzymes, destroying bacteria.

228
Q

phytochemicals roles in foods

A

impart tastes, aromes, and colours

229
Q

2 phytochemicals who are through to reduce the risk of cancer

A

phytoestrogens and lycopene (a carotenoid)

230
Q

What are phytoestrogens and where are they found?

A

Phytochemicals that weakly mimic or modulate effects of estrogen. Found in soybeans, flaxseeds, whole grains, veggies and fruits

231
Q

What is lycopene, and where is it found?

A

A carotenoid that acts as a powerful antioxidant that inhibits the growth of cancer cells when consumed as part of food (not supplements). Found as a red pigment in tomatoes, papaya, and grapefruit.

232
Q

What are flavonoids?

A

Powerful antioxidants that may protect against LDL oxidation, minimize inflammation, and reduce platelet aggregation and blood clotting.

233
Q

Where are flavonoids found?

A

Found abundantly in fruits (berries), tea, herbs, spices, nuts, red wine, dark chocolate

234
Q

What are phytosterols, and where are they found?

A

Cholesterol-like molecules found in plants that inhibit cholesterol absoprtion in the stomach. Reduce LDL cholesterol while keeping stable HAL. Reduces inflammation and blood pressure. Found in SOYBEANS

235
Q

What are lignans, and where are they found>

A

Similar action to phytosterols in terms of CVD. Can be converted to phytosterols in the intestines by bacteria. Found in whole flaxseed

236
Q

What are dietary supplements?

A

defined as any pill, capsule, tablet, liquid or powder intended to increased dietary intake of a particular dietary component

237
Q

Examples of dietary supplements

A

vitamins, minerals, herbs, botanicals, amino acids, combinations of the above

238
Q

Percentage of females that use supplements in Canada? Males?

A

47% females, 34% males

239
Q

Increased prevalence of supplement use in Canada is associated with?

A

increasing age, female gender, increasing education, increasing income

240
Q

Arguments for supplement use?

A

To correct or prevent overt deficiencies. To support increased nutrient needs that may be difficulr to attain without supplements (iron in women, folate in women, newbowns require a single dose of vitamin K, etc). To improve nutritional status. To improve the body’s defenses

241
Q

Examples of why supplements are needed for increased nutrient needs that may be difficult to attain without supplements?

A

Iron in females with high losses. Folate for women of childbearing age. Newborns require a single dose of vitamin K. Vegans and those with atrophic gastritis need B12 supplements. Olders adults need more vitamin D.

242
Q

Why would supplements be needed to improved nutritional status?

A

Treating subclinical deficiencies in older people. Habitual dieters with low energy intakes or who restrict entire food groups. Vegetarians in some cases. Food allergies or intolerances.

243
Q

Arguments against supplement use?

A

Increased risk of toxicity, life threatening misinformation, can provide a false sense of security, bioavailability/biological activity is different than food sources, and antagonistic effects

244
Q

What minerals and vitamins have the highest likelihood for toxicity?

A

Fe, Zn, vitamin A, and niacin

245
Q

For dietary improvements, what should the first line of defense be?

A

Dietary improvement

246
Q

What are the 3 things to look for when taking a multivitamin?

A

Look for about 100% of the RDA for most vitamins, not more. Look for minimum amount of minerals due to likelihood of interfering with absorption of other nutrients. Take a look at your diet–principles of a healthy diet should eliminate the need for most people.

247
Q

What is the number one cause of death in Canada?

A

Cancer (30% cancer, 22% CVD, 6% stroke)

248
Q

Diet may be linked to as many as ____ of cancer cases

A

1/3

249
Q

What is carcinogenesis?

A

Refers to the growth of malignant tissue which often occurs slowly over several decades. Arises from the mutation of genes controlling cell division in a single cell, which promotes cellular growth, interferes with growth restraint, prevent cellular death. Daughter cells have similar effects.

250
Q

What is carcinogenesis most often caused by?

A

Gene-environment interactions. Exposure to carinogens can induce genetic mutations or promote proliferation in cancer cells.

251
Q

What are cancer initiators/

A

Initiate cancer development.

252
Q

Alcohol and low fruit/veggies initiates what type of cancer?

A

head and neck cancer

253
Q

Cooking meat at high temps leads to?

A

Carcinogen release

254
Q

Red and processed meats initiates what type of cancer?

A

Colorectal cancer

255
Q

What are promoters?

A

May accelerate the development of pre-existing cancers

256
Q

What are antipromoters?

A

Defend against cancer

257
Q

High animal fat intake promotes what type of cancer?

A

Colon cancer

258
Q

Non-starchy veggies protect against what type of cancer?

A

Esophageal and stomach cancer

259
Q

4 things that can inhibit cancer

A

Fruit/veggies, high fibre diets, dietary antioxidants, some phytochemicals

260
Q

Recommendation: be as lean as possible within the normal range of body weight (BMI 21-23 is most protective). Convincing evidence?

A

Increase body fat leads to an increased risk of colorectal, breast and several other cancers

261
Q

Recommendation: Be as lean as physically active as part of everyday life (>60 mon moderate or >30 min vigorours PA daily and limit sedentary time). Convincing evidence?

A

Decreased risk of colorectal cancer

262
Q

Recommendation: Limit consumption of energy-dense foods and avoid sugary drinks. Consume fast food sparingly if at all. Convincing evidence?

A

Increased risk of overweight

263
Q

Recommendation: Eat mostly foods of plant origin. Eat at least 5 servings of non-starch veggies/fruits; eat mostly unprocessed grains that contribute fiber. COnvincing evidence?

A

Decreased risk of esophageal and stomach cancer (non-starch veggies). Decreaed risk of colorectal cancer (fibre)

264
Q

Recommendation: Limit intake of red meat and avoid processed meat. Less than 500 g per week, minimally processed. Convincing evidence?

A

Increased risk of colorectal cancer

265
Q

Recommendation: Limit alcoholic drinks to less than 2 per day for men and less than 1 per day for women. Convincing evidence?

A

Increased risk of mouth, esophageal, colorectal (men), and breast cancer

266
Q

Recommendation: Limit consumption of salt and avoid mouldy cereals and pulses. <2400 mg daily and avoid preserved foods. Convincing evidence?

A

Increaed risk of stomach cancer (salt) and liver cancer (aflatoxins in mouldy stuff)

267
Q

Recommendation: Mothers to breast feed and children to be breast fed. Convincing evidence?

A

Decreased risk of breast cancer (mother). Probable decreased risk of overweight in children.

268
Q

A diet that prevents cancer is one that is….

A

adequate in vitamins and minerals, rich in phytochemicals, antioxidants and fibre

269
Q

The fuel mix during physical activity will depend on?

A

Intensity and duration of the acitivity and the composition of the diet

270
Q

In the first 8-10 seconds of exercise, what is used as fuel source?

A

ATP (small amounts stored in all cells and can deliver immediate energy), CP is stored in the muscle and can be broken down anaerobically and replenish the supplies of ATP

271
Q

What fuel source predominates in anaerobic activity?

A

Glucose

272
Q

What fuel source predominates in aerobic activity?

A

Increasing dependence on fat

273
Q

How many kcals does glycogen supply?

A

About 2000 kncal, enough for about 30 km of running

274
Q

During endurance activity, glycogen supplies about what % of the fuel mix?

A

50-60%

275
Q

Mostly glycogen is used for fuel during the first ____ minutes of moderate activity, after which greater and greater proportions of fat are used.

A

20 minutes…glyocogen stores will eventually be depleted

276
Q

How many kcals are available from fat stores?

A

more than 70,000…virtually unlimited

277
Q

When is fat the primary fuel?

A

Activities lasting greater than 20 minutes at moderate intensity

278
Q

What type of diet spares the use of protein for energy?

A

When the diet is adequate in energy and rich in CHO, less protein is used than with high fat or high protein diets. Adequate CHO spares protein.

279
Q

Are athletes’ protein recommendations substantially different than the general population?

A

No…first priority should be adequate energy intake with a priority on carbs…want to eat closer to 65% carbs versus the lower end of 45%

280
Q

Protein recommendations for regular adults, power athletes, and endurance athletes?

A

0.8 g/kg/day, 1.2-1.7 g/kg/day, 1.2-1.4 g/kg/day

281
Q

Fat recommendations for athletes?

A

Follow the same AMDR recommendations for fat intake as the general population (20-35%0. Consuming a diet <20% fat may lead to inadequate nutrient and energy intake. Focus on quality vs. quantity.

282
Q

Adequate hydration is needed for?

A

temperature regulation

283
Q

As little as ___% water loss can lead to greatly diminish performance

A

2%

284
Q

For short bouts of activity (less than 60 mins), what is the best way to stay hydrated?

A

Cool water

285
Q

How much to drink 2-3 hours before activity?

A

500-750 mL

286
Q

How much to drink 15 min before activity?

A

250-500 mL

287
Q

How much to drink every 15 min during activity?

A

125 to 250 mL (drink enough to minimize loss of body weight but don’t overdrink)

288
Q

How much to drink after activity?

A

500 mL for every half kilogram of body weight lost

289
Q

What electrolytes are lost in sweat?

A

Na, Cl, K, and Mg

290
Q

When should a sports drink be consumed?

A

In events that last more than 1 hour.

291
Q

Neglecting to replace Na losses or overhydrating with water along in events that last more than 1 hour can cause?

A

Hyponatremia (low Na in blood)

Physiology 2 (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions