Section 3-6: Inorganic Nutrients Flashcards
Water & electrolytes Minerals & bone health Trace elements
1
Q
Electrolytes consist of…
A
- Na
- K
- Cl
2
Q
Early symptoms of water intoxication are similar to…
A
dehydration
3
Q
For AI, populations has an adequate intake if ____ of the population has an intake greater than the AI
A
> 50%
4
Q
cut-off for accessing AI is…
A
50%
- 50% = population has adequate intake
5
Q
why do we add so much sodium to our food?
A
- taste
- hold water
- preservative
- cheapest ingredient to add to make food taste good
6
Q
effect of food processing on Na and K
A
before processing: very little Na, a lot of K
after processing: slight decrease in K, dramatic increase in Na
7
Q
dietary factors that increase blood pressure
A
- salt sensitivity
- high Na intake
8
Q
salt sensitivity
A
body wants to retain Na
- low Na excretion
- Na cause vasoconstriction
9
Q
UL for Na
A
2300 mg
10
Q
a diet high in K and low in Na…
A
reduce risk of high BP → reduce risk for stroke & heart disease
11
Q
AI for potassium
A
4700 mg
12
Q
which food is a great source of K?
A
potato (baked)
13
Q
what is an often forgotten group of foods that provide great nutrients?
A
white vegetables
14
Q
complications of pregnancy
A
High BP
- gestational hypertenstion
- pre-eclampsia → eclampsia
15
Q
pre-eclampsia
A
multi-system disorder of pregnancy
- high blood pressure
- fluid retention
- rapid weight gain
16
Q
symptoms of eclampsia
A
- seizures
- death
17
Q
which supplement may help relieve complications of pregnancy?
A
Ca++
18
Q
define: mineral
A
inorganic elements needed by the body in small amounts
19
Q
what are the major minerals?
A
- Na
- Mg
- K
- Ca
- P
- S
- Cl
20
Q
Minerals can be categorized into 2 categories:
A
1) major minerals
2) trace minerals
21
Q
How do we get all required minerals?
A
eat a variety of foods from different groups
22
Q
sources of minerals in Canadian diet
A
- Natural sources
- fortified foods
- NHP
23
Q
which minerals are found in fortified food?
A
- iron
- Ca
- Iodine
24
Q
which minerals are found in NHP?
A
Ca supplements (usually needed by older women)
25
Bioavailability of minerals: which are low and which are high?
low: iron, Ca
high: Na (100% available)
26
___ decreases absorption of minerals by binding to them
phytate
oxalate
tannins
27
sources of phytate. what minerals does it bind?
grains;
| Ca, Zn, Fe, Mg
28
sources of oxalate. what minerals does it bind
spinach & veggies;
| Ca, Fe
29
sources of tannins. What minerals does it bind?
tea & coffee;
| Ca, Fe
30
Are most Canadians getting enough Ca from food? Which group is the worst?
no; worse as you get older & females
| - this is because they have higher requirements
31
Are most Canadians getting enough Ca from food + supplements?
No
32
Are Canadians getting enough of P from food?
Yes, maybe too much
33
Are Canadians getting enough of Mg from food?
No
34
sources of Mg
- milk
- whole grains
- fruits & veggies
35
in the body, minerals act as ___
cofactors
| - activate incomplete enzymes
36
osteoporosis is defined as...
loss of both protein (organic matrix) and inorganic matrix (mineral / hydroxyapatite) components of bone
37
vegetables low in ___ are good sources of Ca
oxalate
38
absorption of Ca is most efficient in ___ at __&, and only ___% in ___
infants; 60%
adults; 25-30%
39
adults with vit D deficiency can only absorb ___% of Ca
10%
40
what happens to Ca absorption during pregnancy?
increases
- we also require more Ca during pregnancy
- RDA remains unchanged b/c you can absorb more from the same amount
41
RDA for Ca takes into account...
low absorption rates
| e.g. body needs 300 mg so RDA = 1000 mg
42
calcitonin is produced by...
thyroid gland
43
function of PTH
- reabsorption of bone
- more Ca reabsorbed by kidney
- faster formation of vit D in kidney
44
non-bone related functions of Ca
- muscle contraction (!!)
- NT release
- blood clotting
- regulating BP (counterbalances Na)
45
Observational studies show inverse association between Ca and...
Hypothesis?
colon cancer;
| ca bind with toxins in the colon → insoluble → biologically inactive
46
mineral component of bone
- collagen = organic matrix
| - hydroxyapatite = inorganic matrix
47
trabecular bone
spongy bone that is metabolically active
- reabsorption will happen here
- too much lost → fractures
48
2 types of bone
1) trabecular bone
| 2) cortical bone
49
cortical bone
compact bone (outside)
50
hydroxyapatite
deposits mineral on collage to give bone strength & regidity
51
collagen in bone allows...
some flexibility; bone can be stressed without breaking right away
52
below -1 ~ -2.5 SD for bone density =
osteopenia
53
below -2.5 SD for bone density =
osteoporosis
54
bone loss is a natural part of ___
aging (more loss from trabecular bone)
55
which parts of the body is vulnerable to osteoporosis?
hip & spine
56
why do old people get shorter?
segment of spine have less trabecular bone → front end crushed → triangular shape → spine bends forward
57
consequence of spine bending forward?
```
compression of internal organs
→ respiratory tract infections
→ bronchitis
→ hard to clear congestion
some infections may be deadly in elderly women (e.g. pneumonia)
```
58
Which groups are at the highest risk for osteoporosis?
- women (less peak bone mass & post-menopause bone less)
- older
- Caucasians, SE Asians
- family history
- thin, light individuals
- smokers
- no exercise
- alcoholics (body can't absorb Ca)
- diet lacking Ca and vit D
59
how does exercise improve bone health?
Weight bearing exercise → put stress on muscle → muscle put stress on bone → build bone density
60
define: accretion
uptake & accumulation of Ca from diet
61
why are post-menopausal women at such high risk for osteoporosis?
Bones love estrogen → stimulate osteoblast activity
| - loss of estrogen after menopause cause faster decrease in bone mass when aging compared to men
62
men have estrogen in their body by...
conversion from testosterone
63
both men & women lose bone slowly after age __
35
64
What is a way to prevent weak bones when older?
Achieve higher peak bone mass in your 20s
- although there is still a decrease, the slope is the same
- final bone mass will be higher if max value is higher
65
older people are more vulnerable to osteoporosis because...
osteoclast activity > osteoblast
66
what are ways to minimize bone loss during aging?
- maximize peak bone mass when young (exercise)
| - take Ca & vit D supplements
67
people with bone fractures due to osteoporosis are ___x more likely to die. Why?
3-4
- loss of muscle mass
- immobility → vulnerable to pneumonia
68
why is canned fish a good source of Ca?
Mash in bones when eating
69
Ca supplements without vit D can increase risk of...
| However, this is not relevant because...
```
heart attacks (observational study);
almost all Ca supplements contain vit D
```
70
Mg is a part of ___ of bone
inorganic matrix
71
Mg is needed for...
vit D function
72
#1 micronutrient deficiency in the world =
iron
73
#2 micronutrient deficiency in the world =
iodine
74
Are Canadians getting enough iron?
Mostly yes, but not premenopausal women (higher requirement)
75
are Canadians getting enough of zinc?
No, especially in older people
76
myoglobin has __ subunits
1
77
iron is an essential component of the ___. Why?
heme group;
| needed to bind O2
78
Heme group can be found...
inside hemoglobin & myoglobin
79
efficiency of Fe absorption
5-15%
80
which form of iron is best absorbed? What are the sources of this?
Heme iron (animal sources)
81
Which form of iron is worst absorbed? what are the sources of this?
non-heme iron
- plant sources
- legumes
- grains
82
what is an unexpected source of iron? how to increase this source?
iron cookware
| - acidic foods increase leaching
83
what increases Fe absorption
- ascorbic acid
| - MFP
84
digestion of Fe
stomach:
- non-heme iron (Fe3+) in ferric form → Fe2+ (ferrous form)
- ferrous form can be absorbed
85
Fe supplements contain ___. Why?
ascorbic acid; needed for / improves the absorption of iron
86
MFP
meat, fish, poultry protein
87
what happens to ferritin bound Fe when the cell dies?
lost in feces
88
Fe is converted to ferric form by...
Cu-containing compounds
89
excess Fe is bound to ___ in the ___
Ferritin & Hemosiderin;
| liver
90
Iron loss is due to...
blood loss
| Fe is usually not excreted
91
ferritin binds which form of iron?
Fe3+ (ferric)
92
___ is needed to absorb iron. Why?
Cu-containing compounds;
| allows Fe3+ to be transported into bloodstream
93
Why is free iron dangerous? What does iron do in the blood?
Fenton reaction: iron + H2O2 → hydroxal radical
Iron always bound to some protein to avoid oxidative stress
94
You have little // a lot of transferrin receptors when there is low serum Fe
a lot
95
where can ferritin & hemosiderin be found?
liver & bone marrow
96
iron RDA for women vs. men
women need more iron
97
iron RDA for omnivores vs. vegetarians
vegetarians need more
98
what happens to RBC when there is iron deficiency?
Not enough Fe to make hemoglobin (heme group) → blood can't carry as much O2
microcytic & hypochromic
99
during Fe deficiency, where is Fe lost first? where is it lost last?
Iron stores (ferritin) → iron in plasma (transferrin) → iron in RBC (heme)
100
___ gives a good measure of how good your iron stores are
serum ferritin
101
Catalase
converts H2O2 → H2O
102
breast milk does not contain a lot of which mineral?
iron
103
what should babies by supplemented with in terms of iron?
- infant has 6 mon worth of iron stored in liver
- after 4-6 months, babies should be supplemented with iron
- feed iron-containing foods when baby can begin eating
104
which 2 minerals complete for absorption?
Ca and Iron
105
during pregnancy, which mineral is especially needed (supplement)?
Iron
106
___ supplements would make a lot of women feel better from the tiredness after pregnancy
iron
107
___ deaths/year during childbirth
50000
108
Iron deficiency anemia is due to...
poor diet:
| - too much Ca interferes w/ Fe absorption
109
symptoms of iron deficiency anemia
fatigue → physical inactivity → weight gain
110
Genetic cause of iron overload
hemochromatosis
111
what are some ways to protect from too much free iron?
chelating agent
- make iron biologically inactive
frequent blood donations
112
good sources of zinc
animal products
113
zinc deficiencies are more common in populations with...
high phytates & low animal products
114
symptoms of zinc deficiency
- stunted growth & sexual development
| - weak immune system
115
__ bread is high in phytates, but __ bread is not
unleavened;
| leavened (yeast destroys phytate)
116
high Zn intake stimulate...
synthesis of metallothionein protein
- binds metals inside mucosal cell in small intestines
- interfere w/ zinc metabolism
117
Role of Zn in gene expression
zinc fingers on DNA binding protein receptors
118
function of zinc (give example)
component of many enzymes
| e.g. superoxide dismutase: prevent oxidative stress by breaking down superoxide
119
what common "medicine" is Zn found in?
zinc lozenges
- limit intake to less than 7 days
- daily dose exceeds UL
120
Effect of Zn on Cu
too much Zn → metallothionein → bind Cu → reduced Cu absorption
121
Cu is co-factor in enzyme ____
superoxide dismutase
122
Cu and Zn is lost when ____
mucosal cells die
123
Mn is a component of ____
superoxide dismutase
124
selenium deficiency causes what disease?
Keshan disease
- muscular discomfort
- weakness
125
too much selenium causes...
hair & nail brittleness
126
amount of Selenium in food depends on...
amount in soil
127
sources of iodine from diet
- seafood
- plants that grow near sea
- iodized salt
128
iodized salt is not used in...
processing (we'll get overdose if that happens)
129
iodine is a component of ____ hormone
thyroid
130
thyroid hormone is responsible for...
energy metabolism
131
receptor for thyroid hormone
nuclear protein receptor
132
___ containing enzyme converts T4 → T3
selenium
133
iodine deficiency cause which characteristic physical symptom?
goitre (enlarged thyroid gland)
134
iodine deficiency during pregnancy causes...
cretinism in baby: short, developmental delay, deafness
135
TRH is from hypothalamus. TSH is from...
anterior pituitary
136
subsistence farming
eat only food that is grown in the area
137
intake of iodine correlates with ____
urine excretion
138
are Canadians getting enough iodine?
mild iodine deficiency, but there are excesses as well
| → overall we are okay
139
iodine status in Australia
- most iodine came from contamination (cleaning products used in dairy farms)
- when dairy farms stopped using iodine to clean, Australia became iodine deficient
- now: iodized salt
140
Chromium enhances ___ function by...
insulin;
| activating peptide that binds to insulin receptor → allow glucose to enter cell easier
141
are people chromium deficient?
nope
142
functions of fluoride
- reduce tooth decay
| - strengthen bone (fluorapatite replaces some hydroxyapatite)
