minerals Flashcards
(151 cards)
1
Q
what are the two mineral classes?
A
Macro-minerals
Micro-minerals
2
Q
what percent in diet is a macro-mineral?
A
> 0.01% (100mg/kg) in diet
3
Q
what percent in diet is a micro-mineral?
A
< 0.01% (100mg/kg) in diet
4
Q
Name the seven Macro-minerals
A
Calcium Phosphorus Sodium Chlorine Potassium Magnesium Sulfur
5
Q
What are the 14 micro-minerals?
A
Iron Manganese Copper Selenium Molybdenum Fluorine Iodine Silicon Cobalt Chromium Zinc vanadium nickel arsenic
6
Q
What is the elemental compositions of most species in regards to one another? What is the exception and why?
A
Most species have a relatively uniform elemental composition, except in young animals, which have lower Ca and P.
7
Q
Dietary requirement is highly correlated with what?
A
body level
8
Q
Concentration in animal tissues of Calcium
A
15 g/kg BW
9
Q
Concentration in animal tissues of phosphorus
A
10 g/kg BW
10
Q
Concentration in animal tissues of potassium
A
2 g/kg BW
11
Q
Concentration in animal tissues of sodium
A
1.6 g/kg BW
12
Q
Concentration in animal tissues of chlorine
A
1.1 g/kg BW
13
Q
Concentration in animal tissues of sulfur
A
1.5 g/kg BW
14
Q
Concentration in animal tissues of magnesium
A
0.4 g/kg BW
15
Q
What are the structural functions of minerals?
A
components of bone and tissues, eg. Ca, P, and S
16
Q
what are the electrochemical functions of minerals?
A
acid-base balance, osmotic control, H2O balance, eg. K, Na, and Cl
17
Q
What are the catalytic functions of minerals?
A
component of hormones and enzymes, eg. S, Mg, Fe, Zn, Cu, I
18
Q
Which mineral is the most abundant mineral element in the body?
A
Calcium
19
Q
What percent of body weight is calcium in humans and animals?
A
1-2% of body weight
avg. human is 1.2 kg of Ca (90kg man)
avg. dairy cow is 9.4 kg Ca (600 kg cow)
20
Q
Dietary sources of calcium for humans
A
milk and dairy products (75% of total)
legume seeds
21
Q
good dietary sources of calcium in animals
A
- Legume roughage - 1-2% of DM
- animal by-products (meat by-products): 5-12% of DM
- fish meal: 3-8% DM
- ground limestone and dicalcium phosphate (dairy cows and laying hen diets) 30-40% of DiCal-P
22
Q
Poor dietary sources of calcium in animals
A
cereal grains and roots - < 0.2% of DM
23
Q
Functions of Calcium
A
Bone and teeth: 46% minerals by weight
egg shells: almost pure CaCO3
Muscle contraction and nerve impulses
Acid-base balance: cation-anion balance of diets
blood clotting mechanism
24
Q
What mineral salts are in bones/teeth?
A
hydroxyapatite crystals: 36% Ca, 18% P, and 1% Mg
3 Cac (PO4)2 x Ca(OH)2 Ca:P ratio = 1.3 to 2:1
25
what is the Body distribution of Calcium
99% in bone and teeth
| 1% in blood, body fluids, and within cells
26
what is the Blood distribution of calcium
Plasma Ca(2+) levels
mammals: 2.25-2.75 mM (90-110 mg/liter)
poultry: 7.5 - 10 mM (300-400 mg/liter)
27
Where is calcium absorbed?
in the duodenum and jejunum
28
how is calcium excreted?
urine (20-30%)
feces (70-80%)
Perspiration (minor)
29
what ion is necessary at all steps in Fibrin formation?
Calcium (2+)
30
What are the ten factors influencing calcium absorption?
1. the sources of calcium
2. dietary acidity
3. sugars
4. vitamins
5. estrogen
6. age
7. excess phosphorus
8. phytate
9. Diet Fat content
10. Oxalates
31
How do the sources of calcium affect absorption?
Cereals: low in Ca, plus contain phylates which chelate Ca and reduces absorption in monogastrics
Bone meal: Ca 100% available
Alfalfa: Ca low in availability (16-88%)
32
How does diet acidity affect calcium absorption?
increases absorption by increasing solubility of Ca-chelates
33
How do sugars affect Ca absorption?
Lactose- Increases Ca passive absorption in suckling animals
34
How do vitamins affect Ca absorption?
increase Ca absorption via Calbindin
35
How does estrogen affect Ca absorption
increases it
36
Post-menapausal women are at risk for what disease and why?
at risk for osteoperosis
have low estrogen levels
37
How does age affect Ca absorption?
decreases with age
38
how does excess phosphorus affect Ca absorption?
causes it to decrease
39
How do phytates affect Ca absorption?
chelates and binds Ca (and P)
40
How do oxalates affect Ca absorption?
forms Ca-Oxalate (insoluble); reduces absorption
41
How does diet fat content affect Ca absorption?
excess dietary fat reduces Ca absorption due to fatty acid Ca-soap formations
42
What is phytic acid?
the plants' storage form of phosphorus
43
where does chelation occur? On what?
Occurs in plants and in digestive tract
chelates all cations (Mg, Zn, Cu, Ca, Mn, Fe, and K)
44
High Ca-Phytate prevents release of what by What?
Phosphorus by animal phytases
45
If there is low Ca, what gland is activated?
parathyroid gland
46
What hormone does the parathyroid gland release?
PTH
47
what does PTH do?
- Induces Kidney
- 1-alpha hydroxylase
- Ca reabsorption at kidney
- Phosphate exretion at kidney
48
Vitamin D is released in what form?
1, 25 (OH)2D
49
What does 1, 25(OH)2D do?
- promotes Ca reabsorption at kidney
- Promotes Ca resorption from bone
- promotes Ca and PO4 absorption from the intestinal tract
50
If there is high Ca, what gland is activated?
Thyroid gland
51
what does the thyroid gland release?
calcitonin
52
what does calcitonin do?
suppresses PTH release and action
this suppresses 1, 25 (OH)2D
inhibits Ca reabsorption at kidney
53
what does calcitonin do?
suppresses resorption of bone
54
What are the net effects of Calcium regulation?
1. maintain normal plasma Calcium concentration
| 2. keep Ca:P ratio in plasma constant
55
How much calcium does a human need? (old and avg.)
old: 1200mg/day
avg: 800 mg/day
56
Animal calcium daily intake?
```
chick- 1% (rapid bone growth)
laying hen- 3.5% (due to egg shell formation)
swine- 0.8%
calves, lambs, foals- 0.5%
dairy cow- 0.4%
```
57
When does Rickets occur?
Mostly in young growing animals
58
What causes Rickets?
- deficiency of Ca, P, or Vit D (or all)
- Imbalanced dietary Ca:P outside of the 2.5:1 ratio
- Parathyroid hypertrophy: increases PTH (i.e. enlarged gland)
59
What is the mechanism of Rickets?
Continued growth of the collagen and organic matrix BUT no or insufficient mineralization (hydroxyapatite crystals and ossification) for support
60
What is the result of having Rickets?
- soft, light bone
| - muscles continue to grow, increasing the weight on soft bone and causing the bone to bend
61
What is the occurrence of Osteomalacia?
-Occurs in adult animals (adult counterpart to Rickets)
- occurs in animals on a Ca-deficient diet, fail to replace Ca in the bone after resorption process.
- also occurs with Phosphorus and/or Vit D deficiency
62
What is the result of Osteomalacia
brittle, demineralized bones that are easily broken
63
Milk fever (hypocalcemia) occurrence
Occurs within 72 hrs after calving
| -prevalent in high producing cows: cannot meet milk secretion demands
64
What are the symptoms of milk fever?
- low heart rate due to low calcium levels preventing adequate heart impulses
- low body temperature (low blood circulation)
- tetany (muscle tremors)
- collapse
- possible coma and death
65
What are the clinical signs of Milk Fever
Blood Calcium half of normal (5-6 mg/mL)
66
What is the metabolic basis of milk fever?
Bone Ca release is too inadequate to meet Ca Demands for milk production
67
what can be done to treat milk fever?
I.V. Injection of Ca-salts, such as CaCl2, Ca-lactate, and Ca-Gluconate
68
What steps can be taken to prevent Milk fever?
- change form high Ca to low Ca diet 14 days before calving- stimulates mobilization
- high dose Vitamin D injection 5 days before calving; will increase calcium absorption
69
When/ or in whom does Osteoporosis occur?
human females over 50 yrs or near menopause
70
what causes osteoporosis?
age, gender (female), low Ca and Vit D intake, low physical activity
71
What are the results of osteoporosis?
Reduced height and increased susceptibility to bone fractures
72
what happens metabolically in regards to osteoporosis?
decreased mineralization of organic matrix of bone leads to decreased bone mass
73
what can be done to prevent osteoporosis?
- increase Ca intake: halts progression but does not reverse damage
- mineralization can be replenished, but organic matrix cannot (permanent damage)
74
Why is phosphorus important?
it performs 14 vital functions, which is more than any other mineral
75
Does free phosphorus exist? how does it?
No it does not. It is always chelated or bound form as a phosphate
76
How do ruminants get phosphorus?
microbial phytases break down phytic acid in cereal grains to release P for absorption in small intestines
1 phytic acid --> 6( PO3-) + sugar
77
Functions of phosphorus
1. Bone and teeth formation
2. high energy bonds (ATP->ADP, creatine-P-> creatine)
3. lipid transport (phospholipids); P is in all cells!
4. carbohydrate, fat and amino acid metabolism
5. nucleic acid synthesis (DNA, RNA)
6. Enzyme system requirements
7. Milk secretion
8. Osmotic and acid-base balance (phosphate buffer system
78
Body distribution of Phosphorus
- 85% in bone and teeth
- 14% in soft tissue
- 1% in blood (organic and inorganic complexes): 60-90 mg PO4(3-)/L
79
absorption sites of phosphorus
duodenum and jejunum of the small intestine
| --Most P incorporated into phospholipids in intestinal cells
80
Excretion of Phosphorus
Feces:
-minor in carnivores (most P in diet is digested)
- 50% in humans pigs and poultry (due to indigestible form of P)
- herbivores- major route due to saliva/gut excretions
Urine:
major route in carnivores (acid urine and role of PO4(2-) buffer system)
81
how do excess levels of other minerals influence P absorption?
Cations tie up PO4(2-) and decrease absorption
diet acidity (lower pH) helps dissolve precipitates
82
How does the form of phosphate influence P absorption?
- Dicalcium phosphate- 85% available (more soluble)
- Calcium phosphate - 45% available (less soluble)
- Phytate-P (low and variable)
83
How does phytic acid influence P absorption?
P is unavailable unless microbial or plant phytases are present to break down phytic acid
84
What are sources of phytases?
- Plants mostly (eg. high in wheat)
- ruminal and intestinal bacteria
- animal phytase: very low levels of enzyme in intestine
85
How do monogastrics get P from Phytate complex
negligible intestinal phytase activity, some intestinal bacterial phytase, BUT aides little in release P
86
How do ruminants get P from phytate complex
rumen microbial phytases release P from phytate complex in rumen
87
What are some plant sources of Phytate-P?
Corn, Oats, Wheat, Barley, Rice, Soybeans
88
How does Vitamin D affect intestinal absorption of PO4(-)
- increases intestinal absorption of PO4(-)
| - increases reabsorption of PO4(-) in kidney tubules
89
How does PTH affect PO4(-) absorption in intestine?
increases urinary PO4(-) excretion in kidney tubules
90
Dietary Requirements of P
0.3-1% of diet (Ca:P ratio is very important)
91
What are the effects of P deficiency?
- Rickets (same symptoms as Ca)
- osteomalacia (same symptoms as Ca)
- abnormal growth and bone structure
- loss of appetite- anorexia
- pica - abnormal eating and chewing behavior
- low blood P-> hypophosphotemia
92
excess phosphorus can cause what?
- hypterparathyroidism
- increased PTH, which leads to increased Phosphate excretion
- failure of bone calcification
93
High P and mg leads to what
mineral deposits in bladder; urolithiasis
94
What does PTH do?
1. increases Ca and P resorption from bone
2. increases P excretion into urine
3. Increases synthesis of active form of Vitamin D
4. Increases Ca absorption from GI tract
5. Increases Ca resorption from kidney
Result: elevated blood Ca level to normal
95
High blood Ca leads to what
stimulation and release of calcitonin from thyroid gland
96
what does calcitonin do?
reverses PTH functions
97
What are the key regulators in Ca Homeostasis?
Vitamin D
- increases bone resorption
- increases intestinal Ca absorption
Parathyroid hormone (PTH)
- increases bone resorption
- increases Ca re-absorption in kidney
Calcitonin
-decreases bone resorption
98
What do sodium, potassium and chloride function as?
electrolytes
99
what do the electrolytes maintain in the body?
1. osmotic pressure in tissues: maintains normal shape of cells via ion pumps (eg. Na/K-ATPase)
2. Membrane potential: signal transduction through the membranes, eg. neurons and axons
3. acid-base balance: pH maintenance in blood and tissues
100
What is the optimum dietary electrolyte balance?
250 milli-equilvalents/kg diet
101
Ion imbalance affects metabolism of what?
1. energy
2. amino acids
3. vitamin D synthesis
4. calcium absorption
5. kidney function
102
Diet and body ion balance influences what?
1. growth
2. efficiency
3. Appetite
4. eggshell formation
5. milk fever
103
Sodium is the _____ most abundant mineral in the world.
6th
104
what are the sources of sodium?
good sources: animal tissues
| poor sources: vegetables, cereals, forages
105
Body content of sodium in body
0.1-0.2%; 120-140 g Na in 70 kg man.
106
Sodium is a major _____ in ______
cation in extracellular fluid
107
Sodium functions
1. acid/base balance
2. Na+/K+-ATPase pump
- accounts for 20-40% of resting energy
requirements
3. Membrane permeability: (transport and osmotic
regulation (normal H2O distribution
4. Normal kidney function
108
Name the seven sodium deficiencies. What do they result in?
1. inanition (low vitality or exhausted
2. adrenal hypertrophy: enlarged to compensate for low Na+
3. Depraved appetite (cannibalism- especially birds)
4. water intoxication (note: sodium excess leads to fluid retention)
5. Renal failure
6. decreased cardiac output and increased hematocrit (low plasma volume)
7. low arterial pressure
These symptoms result in extreme weight loss and high mortality
109
generally, plants are _____ in Na+ and Cl-
low
110
Distribution of Potassium
- major INTRACELLULAR cation (98% intracellular)
- red blood cells: K+ is 25x more concentrated in RBC than in plasma
- 0.2-0.25% of body weight
- movements of K+ across membrane are always opposite to that of Na+
111
K+ carries out many functions____ of the cell that Na carries out in _____ and ______
inside, plasma, interstitial fluid
112
Functions of K+
1. acid/base balance
2. na+/K+ ATPase pump- neuromuscular function, nutrient transport
3. membrane permeability and osmotic regulation
4. activation of enzymes- glycolysis and glycogen synthesis
5. enhance amino acid uptake
6. stimulate insulin release
7. normal heart activity: K+ has opposite effect on blood pressure than Na+ and Ca++
113
what does an increase in K+ do to blood pressure
decrease it
114
what does an increase in Na+ do to blood pressure
increase it
115
Where is potassium absorbed? How?
in intestines.
via passive diffusion, Na+/K+ ATPase exchange pump
116
Excretion of potassium
90% via urine- active re-absorption maintains body balance
-perspiration
117
Potassium deficiencies
1. muscular weakness/ stiffness in the extremities
2. poor appetite
3. cardiac weakness
4. dehydration- K+ deficiency affects Na+ and water balance
5. Hyperglycemia due to reduced insulin secretion and glucocontrol
6. reduced amino acid uptake and protein synthesis
118
functions of chloride
1. maintain extracellular fluid because Cl- follows Na+
2. HCl synthesis in the gastric mucosa
3. CO2 respiration (RBC and Lungs: chloride shift
119
Chloride is a major______ anion
extracellular
120
chloride defiencies
1. hemoconcentration- increased [RBC], low plasma volume, linked to Na+
2. Dehydration
3. Spontaneous tetany associated with alkalosis- HCO3- increases to compensate for low Cl- ions in blood
121
main sites of chloride absorption
ileum, proximal large intestines, and colon
122
chloride excretion
urine- 90-95%
feces: 4-8%
other routes: skin (sweat)
123
Rich sources of magnesium
in humans:
-meats, peas, and nuts (almonds
in ruminants, swine and poultry
- legume forages
- grains (cereal, soybean meal)
- meat and bone meal
- fish meals
124
Poor sources of Magnesium
milk, corn silage, liver
125
Magnesium functions
- most common enzyme activator
- redox potential of Mg2+ makes it a preferred cofactor in many enzymes systems- co-factor for over 300 enzymes
- involved in reactions involving ATP
-Mg2+ is essential for growing and actively metabolizing cells (role in ATP stabilization)
126
Body distribution of Magnesium
60% of body's Mg is in skeletal tissue (bone and teeth, storage site)
concentration of Mg in bone ash is 0.5-0.7%
127
factors influencing absorption
- high intake of Ca2+ (antagonizes), PO4- (chelates) or K+ (antagonizes):
- decrease in Mg absorption; decrease in serum and bone Mg
- ruminants: high nitrogen intakes leads to Mg forming insoluble complexes with rumen NH3
- phytates in grains and plants: chelates Mg and decreases absorption
128
homeostasis of Mg2+
no endogenous secretions of Mg2+; it is consumed, absorbed, and excreted
129
Mg2+ deficiencies
humans: 60% of humans eat less than RDA
- --but deficiencies are rare in population
- --prevalent in alcoholics, malnutrition, kidney disease, diarrhea, taking diuretics, lactating mothers
farm animals:
- --ruminants most prone: Mg2+ complexes formed in rumen
- ---other situations
- ------high Ca, PO4, and K intake leads to diarrhea and lactation
130
symptoms of Mg deficiency
- vasodilation, erythema (reddened skin), hyperemia (excess blood in tissues)
- cyanosis (bluish skin)
- hyperactivity and tetany (stiff legs and neck)
long-term advance symptoms
* **calcification of kidney tubules
* **fibrotic and calcified small blood vessels
131
What is grass tetany? Why does it occur?
"grass staggers" occurs in early spring in lush pastures, 1-6 weeks after grazing in spring
-pastures are high in K+ and soluble N (high rumen ammonia)
132
milk tetany (calves)
milk low in Mg for suckling calves
133
what is the most prevalent deficiency worldwide?
Fe2+/3+
134
Good sources of iron
blood meal, meat and bone meal, fish meal
135
poor sources of iron
milk-low in iron
| inorganic sources: ferric sulfate, ferrous sulfate
136
functions of iron
electron carrier in the electron transport chain
| associated with hemoglobin (Fe-Hb)
137
body disribution of iron
65% in red blood cells (gemoglobin)- but RBC not a storage site
25% stored in bone marrow, spleen, liver
138
factors influencing iron absorption
1. valence state of Fe
Fe2+ (reduced) > Fe3+ (oxidized)
2. pH- acidic pH keeps iron in Fe2+ state
139
what inhibits iron absorption?
1. Phytates and fibers
2. oxalates (eg spinach)
3. Ca (competes) and P (phospates bind)
4. EDTA (food additives)
5. Tannic acid and polyphenols in tea and coffee
140
How are baby pigs susceptible to Fe deficiency
low Fe stores at birth and milk is low in Fe
141
How are humans susceptible to Fe deficiency
pregnancy, menstruation, blood loss from injury or gastric ulcers
142
Symptoms of Fe Deficiency
1. thinning of epithelial tissues of mouth/digestive tract.
2. lassitiude (weakness, exhaustion)
3. eyes and mouth=> pale coloration
4. reduced melanin production- lightened hair color
5. muscle weakness
6. labored breathing (related to Fe-Hg)
7. enlarged heart
Hypochromic microcytic anemia (small and pale)
143
Copper sources
animals: corn gluten feed/meal, grass hays, soybean meal, colostrums, copper carbonate, copper sulfate
humans: liver and kidney, shellfish, legumes, nuts and seeds, chocolate
144
Functions of copper
1. hematopoiesis (RBC synthesis)
2. co-factor for lysyl oxidase
3. cotochrome C oxidase
4. Ceruloplasmin (required for iron transport and storage)
5. superoxide dismutase (Cu is co-factor, destroys free radicals)
6. Myelin sheath formation
7. Cu facilitates Fe absorption and liver Fe release
145
Distribution of Cu in body
- liver (reflects dietary dietary Cu intake)
- hair/wool (reflects dietary Cu intake)
- in blood Ceruloplasmin (90%), albumin and erythrocuprein
146
factors influencing absorption of Cu
```
low pH: increases
high pH: decreases
zinc, Fe, and Manganese: reduces
phytate: decreases (phytate binds to zine)
molybdenum with sulfur
```
147
copper absorption occurs mostly in
the duodenum
148
zinc stimulates_______
metalothionein synthesis-> reduces Cu absorption by sequestering Cu
149
absorption preference
CuSO4> Cu-sulfide > Cu-nitrate
150
Cu deficiency symptoms
- general anemia
- scouring/diarrhea
- loss of crimp in wool
- alopecia
- reduced fertility and fetal death
- RBC and connective tissue development (RBC fragile and rupture of vessel walls)
151
Toxicity of Cu
- acculmulation of Cu in liver
- anemia (excess Cu blocks or ties up Fe)
- Tissue necrosis
- jaundice
