Nutrition - Dietary Requirements

Minerals and trace elements Minerals are vital for good health and have a number of key roles to play in the body. Unlike vitamins, which are organic substances (containing the element carbon), minerals are inorganic and are found in rocks and soil. Vegetables absorb minerals as they grow, while animals digest it through their diet. Like vitamins, minerals can be divided into two groups - those needed in larger quantities (major minerals) and those only required in tiny amounts (trace elements). Minerals needed daily include calcium, magnesium, phosphorus, potassium and sodium. These minerals are present in virtually all cells of the body, ensuring our internal systems function efficiently. Acute imbalances of these minerals can be potentially fatal. Such cases are rarely caused by a poor diet, but usually the result of an illness or other unusual factor. Mineral Why is it important? Where is it found? Recommended daily intake Calcium Essential for healthy bones and teeth. Abundant in milk and dairy products. Very small quantities can be found in dark green leafy vegetables, such as spinach and watercress. 700mg Phosphorous Contributes to healthy cells, bones and teeth. Milk, cheese, fish, meat and eggs. 550mg Magnesium Helps your body to use energy and your muscles to function effectively. Dark green leafy vegetables, such as cabbage and broccoli. 300mg Sodium Helps your body to regulate its water content and your nerves to function effectively. In almost all foods as sodium chloride (table salt) 1,600mg Potassium Helps your cells and body fluids to function properly. In most foods, apart from fats, oil and sugar. Particularly found in fruit and vegetables. 3,500mg Zinc Essential for the body to reach sexual maturity and aids the repair of damaged tissue. Meat, fish, milk, cheese and eggs. 9.5mg for males. 7mg for females. Copper (trace element) Helps the body to use iron properly. Green vegetables and fish. 1.2mg for both males and females. Selenium (trace element) Ensures healthy cells. Meat, fish, cereals, eggs and cheese. 75µg for males. 60µg for females. Iodine (trace element) Helps to make thyroid hormones, which control metabolic activity. Seafood and dairy products. 140µg for both males and females. Without minerals, the body would be unable to build new tissues contract muscles process nerve reactions clot your blood keep your body pH neutral regulate body processes release energy from food Mineral deficiencies Dietary mineral intake must be sustained to maintain physical health. Calcium deficiency can lead to hypocalcaemia (an abnormally low level of calcium in the blood) and osteoporosis. Severe magnesium deficiency can result in low levels of calcium in the blood. Clinical features of copper deficiency include failure to thrive in babies, impaired immunity, anaemia with altered iron metabolism and bone marrow changes. Poor selenium status is linked to a poor immune system and increased susceptibility to illness. It has been suggested that it may be linked to an increased risk of cancer and heart disease. In the UK, iodine is added to salt so deficiency is rarely a problem but disorders include goitre (swelling of the thyroid gland in the neck) and poor fetal growth. A deficiency of phosphorus can lead to severely low phosphate levels, also known as hypophosphatemia. Excessive intake Consuming too many dietary minerals can harm your body. Too much calcium in the blood may cause nausea, vomiting, loss of appetite, increased urination, kidney toxicity, confusion and irregular heart rhythm. High levels of magnesium in the blood can lead to heart problems or difficulty breathing. Copper poisoning can arise from contamination of water and drinks from metal utensils, and contact with copper coins, plumbing fixtures and industrial applications, causing vomiting and diarrhoea. Toxic levels of selenium are rare but can result in gastrointestinal upset, hair loss, fatigue, irritability and mild nerve damage. Consult your GP if concerned about any of these issues.