Minerals (iron, calcium, sodium) Flashcards
Haem iron
Easily absorbed by the body
Found in animal flesh foods
Haem sources
Liver Pâté Kidney Red meat (e.g. pork, beef) Poultry Fish
Non-haem iron
Vitamin C must be eaten with it for it to be absorbed
Found mainly in plant sources
Non-haem iron sources
Dried fruit Green leafy veg Fortified breakfast cereals Wholegrain cereal products Beans Nuts Eggs Quorn
Functions of iron
Needed to form haemoglobin in red blood cells, which transport oxygen around the body to where it is needed to release energy
Required for normal functioning of immune system
Iron deficiency disease
Iron deficiency anaemia, caused when iron levels are low + haemoglobin in the blood is not formed properly
Therefore, oxygen is unable to reach the cells + tissues
What can cause anaemia?
A lack of iron in the diet
Poor absorption of iron in the body
Ongoing blood loss
Rapid growth
Anaemia symptoms
Tiredness (lethargy) Weakness Faintness/dizziness Paleness Inability to concentrate Irritability
Excess iron in the diet
Unusual
May be result of taking iron supplements - these may cause nausea + constipation
Factors that increase iron absorption
Non-haem iron can only be absorbed when vitamin C is present - this is b/c non-haem iron is attached to some components in food and eating vitamin C ensures that non-haem iron is absorbed by the body
Factors that decrease iron absorption
Tannins in tea
Phytate in wholegrain cereals
Phosphates in eggs
Sources of calcium
Dairy products (milk, cheese + yoghurt only)
Green leafy veg
Nuts, pulses + soya products
Tinned fish w/ bones (e.g. tinned salmon)
Functions of calcium
Formation and maintenance of strong bones + teeth
Nerve + muscle function
Blood clotting
Deficiency of calcium
Can reduce peak bone mass, i.e. not enough calcium will be deposited on the bones during adolescence + young adulthood, therefore the bones will never reach their maximum strength (may contribute to osteoporosis in later life)
Rickets in children (bow legs or knocked knees)
Osteomalacia in adults (severe bone pain, muscle weakness)
Link between calcium + vitamin D
Vitamin D enables the body to absorb calcium from food and allows it to be deposited on the bones and teeth.
Factors which maximise calcium absorption
Vitamin D
Lactose in milk
Factor which decrease calcium absorption
Phytates in wholegrain cereals
Oxalates in rhubarb and spinach
Functions of sodium
Works with potassium to help ensure that the fluids inside and outside the cells of the body are balanced (in equilibrium)
Helps nerves and muscles to work effectively
Sodium sources
Table salt (sodium chloride) Salty snacks (eg crisps, peanuts) Processed foods (e.g. most ready-meals) Meat products (eg bacon [especially smoked], ham, sausage rolls) Breakfast cereals Stock cubes Takeaways
Excess of sodium in the diet
Excess of salt is linked to an increase in high blood pressure (hypertension) and this increases the risk of CHD and strokes
Deficiency of sodium in the diet
Rare as there is a high consumption of foods containing sodium in the diet of many people
If someone is in a hot climate and isn’t used to spending long periods of time in the heat, sodium can be lost in sweat. Loss of water and sodium in this way can cause dehydration
Vomiting and diarrhoea can also cause sodium to be lost and therefore dehydration can occur
Symptoms of dehydration
Dry mouth Dry lips and skin Thirst Headaches Dark-coloured urine Light-headedness
