Minerals (AQA GCSE Food Preparation & Nutrition)
Revision Note
Written by: Emma Archbold
Reviewed by: Lára Marie McIvor
Minerals
In our body, a mineral is a naturally occurring element that helps with a wide variety of functions
As a micronutrient, minerals only need to be consumed in small amounts in the diet to maintain a healthy level
Some examples of the main minerals consumed in our diet are:
calcium
iron
sodium (salt)
fluoride
iodine
phosphorus
Calcium
The main function of calcium in the body is to aid with increasing strength in our bones and teeth
Other roles include helping to control muscle contractions and aiding with blood clotting
Dairy products such as milk, cheese, and yoghurt are rich in calcium. It can also be found in:
nuts, soya beans and tofu
oily fish
green, leafy vegetables
bread and fortified cereals
Having a deficiency of calcium in the diet can lead to weak, brittle bones that are prone to breaking
rickets is a condition where bone development in children is stunted and can lead to bone deformities during development
osteoporosis tends to happen more in older people because it involves bones weakening over time. This is a common condition in elderly people but can occur at any age
Consuming an excess of calcium can cause digestive issues like stomach pain and diarrhoea
Dietary reference values state that an average adult should consume 700 milligrams (mg) of calcium per day
Young children with smaller bodies do not need as much - around 450-550 mg per day
teenagers during adolescence should consume more calcium to account for increased bone growth - around 1,000-800 mg per day with differences between males and females
Examples of calcium-rich foods
Myriams-Fotos, via Pixabay
Iron
Iron is an important mineral found in red blood cells
The iron binds to the oxygen when it enters the body in the lungs and carries it around the body to respiring tissues
Red meat, such as beef, is very rich in iron and this iron can be easily absorbed into the blood. Other sources of iron include:
beans and nuts
dried fruit and green, leafy vegetables such as spinach
liver and eggs
fortified cereals and bread
Non-meat products contain a form of iron that is more difficult to absorb called non-haem iron
consuming vitamin C makes it easier to absorb iron during digestion
Vegans and vegetarians must pay careful attention to their diets to ensure they do not become deficient in iron
Anaemia is a condition caused by having a deficiency of iron in the diet
iron carries oxygen to respiring cells that are releasing energy. Without iron, there is less oxygen being delivered to the cells and less energy available to the body
this can result in tiredness and dizziness
reduced respiration and lack of available energy can also result in an increased heart rate and shortness of breath during exercise
Consuming an excess amount of iron can lead to digestive issues like constipation, nausea and stomach pain
Dietary reference values for iron vary between adult males and females because females lose blood during menstruation so new red blood cells containing iron need to be produced to replace those that are lost
females require around 14.8 mg of iron per day, whereas males only require 8.7 mg of iron per day
adolescent males who are growing rapidly require slightly more - around 11.3 mg per day
post-menopausal females who no longer menstruate require the same quantity of iron as males
Examples of an iron-rich food
Alpha from Melbourne, Australia, CC BY-SA 2.0, via Wikimedia Commons
Sodium (salt)
Sodium is a mineral found in table salt
Salt in the blood helps to regulate the water balance between the cells and the blood (due to osmosis)
sodium also plays a role in the passage of nerve impulses, muscle contraction, and respiration
Salt is found in many foods, including:
bacon and cheese
processed foods like tinned foods and ready meals
savoury snacks like salted nuts and crisps
Salt is often found in high levels in many foods as it is used as a common seasoning to increase flavour
Consuming too much salt can be detrimental to health. It can increase blood pressure, which in turn increases the risk of heart attacks and strokes
A deficiency of sodium can lead to muscle cramps and in extreme cases can cause kidney failure, liver disease and heart failure
Dietary reference values for sodium state that adults should not consume more than 6 grams of salt per day
Fluoride
Fluoride is an important mineral to prevent tooth decay and improve the strength of the enamel of the teeth - this is why it is often found in toothpaste and mouthwash products, as well as in food
it can also be used to increase bone strength
Fluoride is often artificially added to tap water and this can vary in quantity between regions, however, it can also be found in natural mineral water
it can also be found in bony fish like sardines, seafood and in tea
A deficiency of fluoride can lead to increased risk of tooth decay
Excess fluoride in the diet can cause staining and 'pitting' in tooth enamel and in extreme cases can lead to a condition called skeletal fluorosis that causes bone deformities
Dietary reference values for fluoride state that adults should consume around 3-4 mg of fluoride per day
Tap water contains fluoride image
Olga Lioncat, via Pexels
Iodine
Iodine is a mineral used to create a hormone called thyroxine, which helps to regulate the rate of metabolism in the body
Iodine can be found in red meat, fish caught from the ocean and saltwater shellfish, cereals and grains, as well as products produced from those grains, such as bread
A deficiency of iodine is rare. If it does occur it can lead to reduced quantities of thyroxine, which can lead to development problems in children and reduced IQ
iodine deficiency can also lead to a swollen thyroid, causing a lump to appear in the front of the neck called a goitre
Excess iodine can increase quantities of thyroxine in the blood, leading to weight gain
Dietary reference values for iodine are that adults should consume around 140 micrograms (mcg) per day, with children consuming slightly less
Phosphorus
Similarly to calcium, phosphorus is also found in bones and teeth and helps to improve strength
it also helps us to release the energy stored in our food
Phosphorus can be found in many foods including red meat, dairy products, fish, bread, oats, beans and lentils
A deficiency of phosphorus can lead to bone pain, fragile bones, stiff joints and fatigue
Excess phosphorus can lead to diarrhoea and stomach pain and can increase the risk of bone fractures
Dietary reference values for phosphorus are that adults need around 550 mg of phosphorus per day
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