Minerals Flashcards
How many nutrients are essential to humans?
- (Minerals, vitamins, amino acids, fatty acids, carbohydrates, water and oxygen)
The quantities of minerals is the same in plant and animal based foods, but the bioavailability is higher in…?
Animal foods
What is defined as a macromineral?
If the requirement is 100 mg or more a day
What is defines as a micromineral?
If the requirement is less than 100 mg a day
Out of the 24 minerals, there are 4 in which deficiencies are prevalent for humans?
Which are these and why?
Iodine, iron, zinc and selenium.
Because of different diets, mainly due to differences in soil around the world.
What are the symptoms of calcium deficiency?
Brittle bones, excessive bleeding, stunned growth
What are the symptomps of phosphorus deficiency?
Bad bones and teeth, body weakness
Where in the body do you primarily find calcium?
99% bound in skeletal tissue
What are the functions of calcium?
- Structural unit of bones and teeth
- Contraction and relaxation of muscle
- Stabilizes nervous tissue
- Required for blood clotting
- Activates various enzymes
What are the two pathways for calcium absorption?
Active transcellular pathway (through cells)
Passive paracellular pathway (between epithelial cells)
Calcium absorption is inhibited by..?
And enhanced by..?
Inhibited by insoluble salts like oxalate and phytate.
Enhanced by vitamin D, lactose, acidic pH
Two compunds strongly inhibit the uptake of iron?
One compund increases?
Phytate and tanins inhibits.
Vitamin C increases.
Which state of iron is more bioavailable?
The reduced state, Fe2+, Ferrous (vitamin C reducerer Fe3+ til Fe2+)
Where and how is iron absorped?
In the upper part of the small intestine (duodenum).
By active transport after gatric HCl release.
How is excess iron eliminated?
There is no effective excretion.
Åreladning is needed, if intoxication happen
What is the function of transferrin?
To carry iron in the blood stream
Which two forms are transferrin stored in?
And where?
Ferritin, a water soluble complex.
Hemosiderin.
In the liver, spleen, bone marrow, intestinal mucosa and plasma
What are the symptoms of zinc deficiency?
Poor growth, delayed wound healing, impairment of sexual development, decreased taste acuity
Where is iodine primarily found in the body?
80% in the thyroid gland (skjoldbruskkirtel)
Which mineral is important for the function of the hormone thyroxine and triiodothyronine?
Iodine
What are the dietary sources for iodine?
Cereals, plants, marine fish, shellfish and salt
Where is iodine absorbed?
In the proximal small intestine (duodenum) as iodide
This mineral has a function in gluthatione peroxidase and has antioxidant activity?
Omdanner bl.a. H2O2 —> H2O
Selenium
How come selenium can be taken up as part of protein?
It can be bound as selenocystein or selenomethionine instead of sulfur.
Uptake and secretion of calcium is controlled by?
parathyroid hormone (PTH), calcitonin and vitamin D
What are food sources of heme and non-heme iron?
Heme: Meat, Poultry, fish
Non-heme: Vegetables, fruit, legumes, cereals
How much of each iron source is absorbed?
20-30% of heme-iron
1-10% of non-heme iron
This mineral is necessary in the form of Vitamin B12
Cobalt
What are functions of the mineral copper?
- Aid iron absorption and hemoglobin formation
- synthesis of phospholipid
- Part of superoxid desmutase
What 2 minerals should take up af 2:1 ratio in the diet?
Calcium and phosphorus
High blood sugar leads loss of X in the urine.
X deficiency can cause insulin resistance.
X: magnesium
What are effects of excess sodium (Na) intake?
- Hypertension
- Edema
What is an important function of potassium?
- It is a major intracellular cation
- Osmotic pressure
- Acid base balance
What are causes of iron deficiency?
Excessive blood loss
Rapid growth in children
Malabsorption after e.g. gastric bypass
How is zinc absorbed and transported?
Taken up by enterocytes and transported to the liver bound to albumin and alpha-2-macroglobulin
Name examples of metalloproteines where zinc is involved
Carbonic anhydrase, metalloproteases, RNA/DNA polymerase
What are sources of copper?
Drinking water (due to water pipes)
Sea food, meats, nut and whole grain
What are functions of phosphorus?
- ATP
- Phospholipids
- pH regulation (phosphate buffer)
What are functions of sodium/Na?
- Osmotisk ligevægt
- acid/base balance
- CO2 transport
- Cell membrane permeability
Flour is important for?
Tooth enamel and bones
Manganese is important for?
Normal skeletal and connective tissue development.
- Acts as catalyst in enzymes
