A number of inorganic elements or minerals are essential to the human body. Their three main functions are:
- As constituents of skeletal structures of the body and teeth
- As electrolytes to maintain cell structure and fluid
- As constituents of enzyme systems
The dietary source, and body uses of the major minerals can be found in table 3. Minerals required in larger quantities (milligram amounts) include calcium, phosphorus, sodium, potassium and iron.
There is also a group of minerals which are only required in minute quantities (microgram amounts, which is 1/1000th of a milligram). These minerals are called trace elements and are shown in table 4.
Examples of essential minerals12Click to open table
|MINERAL||DIETARY SOURCE||BODY USES||Deficiency symptoms|
|CALCIUM||Dairy products (e.g. milk, cheese, eggs), sardines/salmon, cereal products, nuts||Growth and maintenance of bones and teeth.
Intracellular signalling control of muscles and nerves.
Maintenance of cell membranes, blood clotting, enzyme activity and hormone function
|Reduction in peak bone mass and bone mineral content, increased risk of osteoporosis|
|PHOSPHOROUS||Present in all natural foods and many additives.
In particular dairy foods, cereals, meat and meat products, fish, nuts, fruit and vegetables.
|Contributes to normal function of cell membranes.
Contributes to the maintenance of normal bones.
Contributes the maintenance of normal teeth.
|Bone changes as above|
|SODIUM||Present, often in alarming quantities, in processed foods||Maintains proper fluid balance essential for muscle and nerve function||Hyponatraemia / muscle cramps|
|POTASSIUM||Vegetables, meat, milk and coffee||Maintains proper fluid balance essential for muscle and nerve function||Hypokalaemia - symptoms of which include anorexia, muscle weakness, paralysis drowsiness and cardiac arrhythmias|
|Iron||Meat, meat products, fish, eggs, bread, cereals and cereal products, vegetables, nuts, dried fruit.||Oxygen transport as component of haemoglobin||Anaemia - pallor, fatigue|
|Zinc||Meat, cereals, dairy products, vegetables, fruit, nuts||Enzyme systems, immune system||Hair loss, diarrhoea, dermatitis, psychiatric disorders, weight loss, hypogonadism in males and poor ulcer healing|
Trace Elements12Click to open table
|MINERAL||DIETARY SOURCE||CONTRIBUTES TO||Deficiency Symptoms|
|COPPER||Liver, vegetables, nuts, plain chocolate||Iron absorption, enzyme systems||Bone disorders, impaired immunity|
|IODINE||Milk, fish, dairy products||Required for synthesis of thyroid hormone||Goitre, hypothyroidism|
|FLUORINE||Drinking water, tea, seafoods||Incorporation into bone and teeth||Dental caries|
|MANGANESE||Bread and cereal products, milk, fruit, nuts||Activation of several enzymes, regulation of glucose homeostasis and calcium mobilisation||Weight loss, dermatitis, depressed growth of hair and nails|
|MAGNESIUM||Cereals and cereal products, meat and meat products, milk and milk products.||Enzyme systems, synthesis of DNA and RNA||Muscle spasm, tremors, personality changes, lethargy, cardiac arrhythmias, sudden cardiac death|
|CHROMIUM||Brewers Yeast, wholegrain cereals, broccoli, processed meats||Glucose metabolism||Glucose intolerance|
|SELENIUM||Meat, cereals, fruit, nuts||Protects against oxidative damage||Muscle pain and tenderness, heart disease, low thyroid function|