Download Minerals

© PDST Home Economics
Major mineral
Calcium (Ca)
Trace mineral
Iron (Fe)
Phosphorus (P)
Chlorine (Cl)
Sodium (Na)
Potassium (K)
Zinc (Zn)
Copper (Cu)
Manganese (Mn)
Fluorine (F)
Magnesium (Mg)
Iodine (I)
Chromium (Cr)
Cobalt (Co)
Selenium (Se)
Iron is an important mineral
 Deficiency in iron is the most common mineral
deficiency in humans
 Iron is present in haemoglobin in the blood,
myoglobin in the muscles, enzyme systems in
the body cells, and is also stored in the liver,
spleen and bone marrow

Functions
Effects of
deficiency
Sources
RDA (mg/day)
•Iron is necessary
for the formation
of haemoglobin,
which carries
oxygen around the
body
•Iron deficiency causes
haemoglobin levels to
fall, which means that
there is not enough
oxygen going to the
body tissues
• Children 10
•Adolescents 13-14
•Adults: Males 10, f
females 14
•Pregnant or
lactating women
15
•Its forms part of
myoglobin which
carries oxygen to
the muscles
•It
1.
2.
3.
4.
•Meat
•Meat products
•Chicken
•Cereals
•Eggs
•Pulses
•Green
Vegetables
•Fish
•It is an important
part of enzyme
systems that use
oxygen to release
energy from food
•
can lead to:
Tiredness
Paleness
Breathlessness
Anaemia
Anaemia is a
common condition
in Ireland
especially women
Definition & Cause: Anaemia is a disease
caused by a shortage of haemoglobin, as a
result of insufficient iron in the diet, or an
inability to absorb iron
 It is more common in females due to
menstruation
 Symptoms: Tiredness, dizziness, headaches,
paleness, shortness of breath & loss of
appetite

Haem iron
• This is ferrous iron
• Its chemical symbol is Fe²+
• It is soluble & easily absorbed
•Sources of haem iron include
meat, meat products, chicken
Non-haem iron
• This is a ferric iron
•Its chemical symbol is Fe²+
•It cannot be absorbed in the
body & must be changed into
ferrous iron to be absorbed
•Sources of non-haem iron
include cereals, eggs, pulses,
green vegetables, fish
Factors aiding iron absorption
Eating haem iron (because it is more easily
absorbed than non-haem iron)
 Eating non-haem and haem iron together
increases non-haem iron absorption
 Vitamin C is a reducing agent, as it changes
ferric iron (Fe³+) to the more easily absorbable
ferrous iron (Fe²+)
 Hydrochloric acid in the stomach aids
absorption by changing non-haem iron to haem
iron

Factors hindering iron absorption
Phytic acid, in cereals and legumes, binds to
iron, decreasing its absorption
 A dietary fibre intake above 35g per day has a
tendency to bind iron, decreasing its absorption
 Oxalic acid, which is found in some fruit and
vegetables (rhubarb & spinach), combines with
iron, inhibiting its absorption
 Tannins in tea, coffee & cocoa decrease iron
absorption.


99% of calcium in the human body is present in
human bones
Functions
Effects of Deficiency Sources
RDA mg/day
•Calcium plays a major
•Rickets
•Dairy products,
•Children
 It is also found
in
the
blood,
muscles
and
nerves
role in the formation &
•Osteomalacia in
e.g. Milk,
800
development of bones & adults
cheese, eggs
•Adolescents
teeth
•Osteoporosis in the •Dark green
1200
•Calcium is important in
elderly
vegetables e.g. •Adults 800
blood clotting
Spinach,
•Pregnant/
•Calcium is necessary for •Tooth decay
•Poor blood clotting cabbage
lactating
muscle contractions,
•Failure of the
•Canned fish,
women 1200
normal functioning of
nerves & membrane
muscles to relax
e.g. Salmon
permeability
(muscular spasms)
•Fortified Flour
•Calcium is required to
•Hard water
regulate metabolism in
the cells
10
Factors aiding calcium absorption
Vitamin D which stimulates calcium binding protein
& increases absorption
 Parathormone is a hormone that controls the level
of calcium in the blood (It is produced by the
parathyroid gland)
 Amino acids combine with the calcium salts, which
are absorbed easily
 Phosphorus combines with calcium to form calcium
phosphate
 An acid environment helps calcium absorption
(eating vitamin C with calcium rich foods)

Approx. 20% of Calcium intake is absorbed
in the small intestine where it is bound to a
specific carrier protein
Factors hindering calcium absorption
Phytic acid, present in cereals and grains binds to
calcium, preventing its absorption
 Oxalic acid, present in rhubarb & spinach, binds to
the calcium, preventing its absorption
 Fibre binds to calcium, preventing its absorption
 Excess saturated fat forms insoluble soaps with
calcium, preventing its absorption
 Overconsumption of soft drinks
 An incorrect calcium/phosphorus ratio
 Levels of oestrogen in postmenopausal women play a
major role in the absorption of calcium
 Tannins in tea

Zinc
Function
•Reinforces the immune system
•Protects against infection
•Needed for:
The metabolism of carbohydrate and protein
The production of male sperm and female ova
The formation of bone tissue and healing
wounds
Sources
•Zinc from animal foods, such as meat, liver, eggs,
poultry and milk, is more readily absorbed than
zinc from plant foods
•Seafood, wheat germs, nuts, pulses, bread
Zinc
Effects of deficiency
•Deficiency is found in those whose diet is high in
refined cereals, and whose intake of animal
protein is low. Deficiency can cause:
Skin problems
General tiredness
Hair loss
Prolonged healing of wounds
RDA
•Zinc is not stored in the body so a daily intake is
required
4 – 7 mg for children
7 – 9 mg for adolescents
7 – 10 mg for adults
Iodine
Function
•Very important as it is a part of the thyroid
hormone thyroxine, which is essential for
normal growth and physical and mental
development
•Also involved in maintaining metabolic rate
Sources
•Fish, meat, milk, table salt
Effects of deficiency
•Deficiency is rare in the Western world but it
may cause:
Goitre
Cretinism
Increased incidence of miscarriage and still
births
RDA
•150 g for adults, 90 g for children
Potassium
Function
•Vital for the correct functioning of the heart muscles and
nerves
•Helps protein metabolism
Sources
•Found in nearly all foods including green veg, wholemeal
products, pork, fruit (especially bananas), fruit juices,
dairy products and grains
Effects of deficiency
•Deficiency is rare but it may cause:
Diarrhoea, excessive sweating, fatique, bloating,
insomnia
RDA
•As potassium is stored in the fluids of the body cells, it is
excreted, therefore a daily intake is essential
3 g for children, 3.5 g for adults
Sodium
Function
•Needed to regulate body fluids
•Needed for energy release
•Needed for proper functioning of nerves and muscle
contraction
Sources
•Smoked fish, soy sauce, ham, bacon, olives, processed
foods and table salt
Effects of deficiency
•As sodium is found in small amounts in many foods and is
particularly high in processed foods, most people have a
higher sodium intake than they need. High sodium intake
has been linked to high blood pressure and strokes
RDA
•RDA met by a high intake of processed foods
Vitamin
Relationship with Minerals
1. Vitamin D
•Works in the absorption of calcium
& phosphorus
2. Vitamin K
•Works with calcium in clotting
blood
3. Vitamin C
•Works in the absorption of iron &
calcium
4. Vitamin B6, B12, Folic Acid
•Works with iron in the formation
of red blood cells
Water (H2O)
•Water is essential for life
•Two-thirds of our body is made up of
water
•Water is the main component of blood,
lymph and digestive secretions, as well as
all other liquid parts of the body
•It is made up of hydrogen and oxygen
molecules in the ratio 2:1
Water
Properties
•Colourless, odourless and tasteless liquid
•Boils at 100°C and freezes at 0°C
•Neutral PH of 7
•Excellent solvent capable of dissolving a number of
substances
•Exists in three states: solid (ice), liquid (water), and
gas (steam)
•Able to absorb heat and maintain it
Sources
•Tap/ bottled water
•Beverages such as tea and coffee
•Fruit and vegetables
•All foods contain a certain amount of water
Water
Functions
•Transporting nutrients, oxygen, enzymes and
hormones around the body
•Removal of waste products from the body, e.g. from
the kidneys
•Quenches thirst
•Contains the minerals calcium and fluorine
•Controls body temperature through perspiration
•Significant in the hydrolysis of nutrients during
digestion
•Essential element of all body fluids and tissues
RDA
•Between 2 and 3 litres per day