Mineral Elements
Inorganic nutrients
© PDST Home Economics
Minerals
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The human body needs 20 mineral elements in small
amounts to protect us from diseases
Major mineral elements
Calcium
Phosphorus
Sodium
Potassium
Magnesium
Chloride
Ca
P
Na
K
Mg
Cl
Trace mineral elements
Iron
Zinc
Iodine
Copper
Fe
Zn
I
Cu
Calcium
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Found in bone & teeth (99%) and rest in blood,
muscles and nerves.
Calcification is the word for the hardening of the
bones
They harden by absorbing Calcium and Phosphorus
(Calcium phosphate)
Sources
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Milk (103mg/100g)
Cheese (800mg/100g)
Yoghurt.
Tinned Fish e.g. Sardines 550mg/100g
Leafy green veg. e.g. Spinach 70mg/100g
Fortified flour
Hard water
White Bread 100mg/100g
RDA
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Children
Adolescents
Adults
Preg/Lac
800mg
1200mg
800mg
1200mg
Functions
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Making strong bones and teeth
Blood Clotting
Muscle contractions e.g. regular heartbeat
Normal nerve function
Calcium Deficiency
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Rickets in children
Osteomalacia
Tooth decay
Poor blood clotting
Irregular muscular contractions
Malfunction of nerve cells
Absorption
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Only 20-30% of the calcium we eat is absorbed.
Certain things help or hinder absorption
Assisting absorption
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Hindering absorption
Vitamin D
Phytates
Parathormone
Oxalates
Phosphorus
Excess fat
Acid environment e.g. eat Excess protein
vit.C with calcium
Wrong calcium / phosphorus
Protein –calcium has to
ratio.
bonds to protein to be
Too many soft drinks
absorbed
IRON
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50% of the iron in the human body is in the blood
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The rest is in the liver, spleen and bone marrow.
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Small amount in muscle protein and cell enzymes.
Sources of Iron
Haem iron sources
Non-haem iron sources
Offal e.g.
liver(11mg/100g)
Meat
Meat products
Chicken
Eggs (2mg/100g)
Whole cereals e.g.
Wholegrain flour (4mg/100g)
Dark green veg e.g.
Spinach (4mg/100g)
Fish
RDA for Iron
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Children
8mg
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Adolescents
14mg
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Adults
10mg
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Pregnancy/Lactation
15mg
Functions of Iron
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Needed to make haemoglobin in the red blood cells
which is needed to carry oxygen from the lungs to the
body cells.
Needed to make myoglobin which carries oxygen to
muscle.
Needed to make certain enzymes.
Iron deficiency
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Tiredness
Muscles tire easily
Paleness
Breathlessness
Anaemia
Anaemia
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Caused by shortage of haemoglobin due to lack of iron
in diet or failure to absorb the iron
More common in females – menstruation
Symptoms: tiredness, dizziness, headaches, paleness,
breathlessness, loss of appetite
Absorption of Iron
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Only 15% of the iron you eat is absorbed.
Things that help iron absorption:
 Source: haem iron is easier to absorb
 Vit C changes ferric iron to the ferrous state which is
easier to absorb.
 If haem and non-haem iron are eaten together
Things that hinder absorption:
 Excess Fibre
 Tannins
 Source: non-haem
 Phytates (in wholegrains), Oxalates (in dark green veg.)
Retaining vitamins & minerals in
food
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Choose fresh food
Don’t store for too long
Store in cool dry dark
place
Eat raw if possible
Avoid peeling
Prep just before use
Avoid steeping
Sharp knife reduces
oxidase damage
Use pre boiling salted
water
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Cook for shortest possible
time
Use as little liquid as
possible
Cover cooking pot
Use cooking liquid in sauce
or gravy
Don’t add bread soda to
greens
Serve immediately after
cooking.
Avoid reheating
Potassium (K)
Sources
Functions
Deficiency
Pulses
Green leafy veg.
Banana
Oranges
Meat
Milk
Fruit juice
Nuts
Fluid balance in
body tissue
Healthy nerves
Normal muscle
activity
Rare
Mental confusion
Cardiac arrest
Weak muscles
RDA:0.8-3.1g
Sodium (Na)
Sources
Function
Deficiency
Salt
Processed food
Smoked food
Cured food
Meat products
Cheese
Snack foods
Fluid balance in
body tissues
Healthy nerves
Normal muscle
activity
Muscle weakness
Muscle cramp
Low blood pressure
Loss of appetite
RDA:1.6g
Zinc (Zn)
Sources
Function
Deficiency
Meat
Meat products
Cereals
Oysters
Legumes
Enzyme activity
Protein & carb.
metabolism
Hormone activity
Healthy hair
Healthy skin
Frequent infection
Reduced appetite
Delayed healing
Dry skin
RDA
7-12mg
Iodine
Sources
Functions
Deficiency
Seafood
Cod liver oil
Iodised salt
Veg. grown in
iodine rich soil
Making the thyroid
hormone thyroxine
Regulates growth &
development
Regulates
metabolism
Goitre
Retarded mental
development
Lethargy
RDA:
70-160μg