A guide to essential minerals including information on calcium, iron and zinc.
Minerals are nutrients found in foods, which are similar to vitamins and which are just as essential for good health. They are a part of all cells, tissues, muscles and fluids in the body and are needed for a variety of chemical processes that take place within the body.
Most people are aware of the importance of a diet that is rich in vitamins and even know which foods contain certain vitamins and what the function of those vitamins is in the body. However, people are not so knowledgeable about minerals and their purpose towards keeping the body working well and maintaining good health.
Minerals such as calcium, zinc and potassium are needed by the body for a number of processes such as breaking down, digesting and releasing energy from food, strengthening bones, nails and teeth and regulating fluid and cholesterol in the body.
There are 16 essential minerals required by the body, which are divided into macrominerals, or minerals that are needed in fairly large quantities, microminerals, which are needed in smaller quantities and trace elements, which are needed in minute quantities but which are still vital for the body's well-being.
The benefits of some minerals cannot be seen without the presence of certain minerals and vice versa, for example, vitamin D is required in order to absorb calcium and when foods containing vitamin C are consumed, iron is absorbed more efficiently.
It must be noted that the quantity of minerals contained in certain foods depends on the amount of minerals present in the soil where these foods were grown or where the animals grazed.
Essential minerals and vitamins can be lost through transporting foods over long distances, poor storage and through cooking.
The following outlines the function of these essential minerals, from which foods they can be obtained and the effect a deficiency of these minerals could have on the body.
Function: Calcium is a macromineral that is needed to maintain strong and healthy bones and teeth. It is also involved in normal blood clotting, muscle and nerve function, lowering blood pressure and is thought to prevent colon cancer.
Sources: Dairy products such as milk, yoghurt and cheese, kelp, broccoli, almonds, sardines eaten with the bones and sesame seeds.
Symptoms of deficiency: Muscle weakness, spasms and cramp, softening of the bones, which could lead to osteoporosis, back pain, brittle bones and fractures.
Function: Required for the formation of acids in the stomach as well as regulating fluid in all blood vessels and cells.
Sources: Table salt and foods that contain sodium chloride.
Symptoms of deficiency: A deficiency is very uncommon but may cause excessive amounts of potassium to be lost and low blood pressure.
Function: A very important macromineral that is contained in our bones. It is needed to convert blood sugar into energy, control muscle and nerve function, maintain a normal heart rhythm and blood clotting. Research has proved that magnesium protects and treats heart disease, lowers high blood pressure, can ease asthma attacks and PMS in women.
Sources: Whole grains, green leafy vegetables, shellfish, nuts and bananas.
Symptoms of deficiency: The risk of heart disease and diabetes is increased and can also cause heartbeat irregularities, confusion, muscle cramps and kidney stones.
Function: Phosphorous is another important mineral involved in the formation and maintenance of strong and healthy bones and teeth. It also helps to supply energy to every cell in the body and is needed to absorb a number of vitamins.
Sources: meat, poultry, fish, milk, cheese, nuts, seeds and whole grains.
Symptoms of deficiency: A deficiency in phosphorous is fairly rare, however, symptoms would include weak and painful bones and teeth, stiff joints, tiredness and a loss of calcium from the body.
Function: Potassium, along with sodium, works to regulate fluid in the body. Potassium also helps to maintain a regular heartbeat and low blood pressure and enables glucose in the body to be converted to glycogen, a storable form of energy.
Sources: Fresh fruit and vegetables, particularly avocados, bananas, oranges, potatoes. Also dried fruit, nuts, seeds, meat, poultry and milk.
Symptoms of deficiency: Muscle weakness, nausea, confusion and feelings of being really thirsty.
Function: Helps to maintain muscles and nerves in good working order and works together with potassium, regulating the fluids in the body.
Sources: Salt, shellfish, anchovies, dairy products especially butter, yeast extracts, processed meats, avocados and offal.
Symptoms of deficiency: A deficiency is very rare but is possible through sweating, diarrhoea or vomiting and symptoms include sickness and dizziness, muscle cramps and dehydration.
Function: Chromium is a trace element that is important in the body. It is able to stabilise blood sugar levels, which could prevent diabetes, by using insulin efficiently. It also aids the break down of fats in the body and is said to increase the good cholesterol in the body while lowering the bad cholesterol.
Sources: Shellfish, red meat, liver, egg yolks, cheese, molasses, brewer's yeast, mushrooms and whole wheat bread.
Symptoms of deficiency: A lack of chromium could bring on the onset of diabetes as well as raise blood cholesterol levels and could lead to heart disease.
: Copper helps to form collagen, which is essential for healthy bones and connective tissue. It is important for the production of red blood cells and is needed to absorb iron more easily. Research suggests that copper may prevent heart disease and high blood pressure and that it protects against damage from free radicals and the development of cancer.
: Offal, oysters
and shellfish, whole grains, nuts, seeds, avocados, potatoes, garlic, bananas, mushrooms, cocoa, tomatoes, prunes and soya products.
Symptoms of deficiency
: Weakness, skin and breathing problems, although a deficiency is not common.
Function: Fluoride is important for healthy bones and teeth and protects teeth against tooth decay.
Sources: Toothpaste, tap water and tea.
Symptoms of deficiency: A lack of fluoride will cause tooth decay.
Function: Iodine plays a major part in the manufacture of certain hormones by the thyroid gland, that are responsible for regulating metabolism, converting fats into energy and stabilising blood cholesterol levels.
Sources: Table salt, seafood, saltwater fish and seaweed.
Symptoms of deficiency: This is extremely rare but a deficiency would lead to an enlarged thyroid gland, dry skin and tiredness.
Function: Iron is required for the production of haemoglobin, the component of red blood cells that transports oxygen around the body. It is also needed to produce myoglobin, which carries oxygen to our muscles. Iron can prevent fatigue, protect against illness and disease and promotes a healthy looking skin.
Sources: Liver, lamb, beef, oysters, shellfish, clams, mussels, beans, peas, yeast, dried fruits, fortified breakfast cereals, molasses, wheat bran and green leafy vegetables.
Symptoms of deficiency: It is not uncommon for people to have an iron deficiency in their diet. This could be the case particularly for women with heavy periods, vegetarians and athletes. Symptoms of a lack of iron include tiredness and fatigue, poor concentration, prone to infection, shortness of breath, anaemia, brittle hair and heart palpitations.
Function: Manganese is important for the protection of the body's cells particularly against damage from free radicals. It is required for the process of metabolism and digestion and helps to break down fats and cholesterol. Manganese is also vital for the formation of healthy bones and tissues.
Sources: Nuts, brown rice, cereals, whole grains and pulses.
Symptoms of deficiency: A lack of manganese can lead to digestive problems, dizziness and loss of hearing.
Function: Necessary for the production of DNA and is also known as an antioxidant. It helps to break down sulfites in foods, where if a toxic build-up occurs, it could lead to an allergic reaction. It is also known to prevent tooth decay.
Sources: Liver, whole grains, yeast, pulses, leafy green vegetables.
Symptoms of deficiency: A deficiency could lead to breathing difficulties and other allergic reactions.
Function: Selenium is an important antioxidant, as it is known to block free radicals in the body. It fights cancer, heart disease and prevents cataracts from forming. It may delay the development of AIDS and reduces the severity of common infections and illnesses.
Sources: Seafood, eggs, offal, dairy products, citrus fruits, brazil nuts, avocados and lentils.
Symptoms of deficiency: A lack of selenium in the diet could lead to a higher risk of cancer, heart disease and skin problems.
Function: Sulphur is an important component of several amino acids, which are needed to form proteins in the body. It is also very good at detoxifying and eliminating any toxins from the body. Sulphur may delay the ageing process and the onset of any age-related diseases.
Sources: Animal and vegetable proteins such as meat, poultry, beans and pulses and shellfish.
Zinc is present in every cell in the body and also in hair, nails and skin. It is needed to maintain a healthy immune system, which can help in keeping colds and flu at bay. Zinc is necessary for a healthy reproduction system, normal growth and can also be taken to treat a number of problems such as fatigue, skin problems and sore throat.
Sources: Oysters, red meat, poultry, eggs, shellfish, cheese, nuts, sunflower seeds, beans and wheat germ.
Symptoms of deficiency: A lack of zinc in the diet is quite uncommon, however, symptoms include more cold and flu bouts, longer healing of wounds, a lesser sense of taste and smell, skin problems, loss of appetite and night blindness.