Vital minerals

Let minerals be a mystery no more! Nutritionist Jo Lewin gives an overview of the most essential, what they do and how to get them naturally.

The human body uses minerals for many things, including keeping bone and blood cells healthy. Minerals work along with vitamins as essential components in enzymes and coenzymes. If an essential mineral is lacking, your body won't be able to work at its best. For example, zinc is necessary for the enzyme which activates vitamin A for good eyesight and without it, vitamin A cannot be used properly by the body. This deficiency may result in night blindness.
 

Calcium

Calcium is important in the activity of many enzymes in the body and is essential for building and maintaining bones and teeth. The contraction of muscles, release of neurotransmitters, regulation of heartbeat and clotting of blood are all dependent on calcium. Periods of growth, pregnancy and lactation may require increased demand. Deficiency in children can result in rickets, in adults it can contribute to high blood pressure and osteoporosis.

How can I get it?
Three portions of dairy per day, such as three slices of cheddar cheese, a yogurt and large glass of milk will provide your recommended daily allowance (RDA).

The best sources of calcium are dairy produce, small-boned fish such as sardines and anchovies, green leafy vegetables, nuts and seeds such as almonds and sesame seeds, tofu and apricots. You can also buy calcium-fortified bread, although it is much better to get it from natural sources.

Phosphorous

Phosphorous is one of the most essential minerals, playing a role in energy metabolism, calcium absorption and converting protein for growth, maintenance and repair of cells and tissues. It is readily available in most foods, including high protein foods.

How can I get it?
The main food sources are meat, milk and wholegrains, nuts and seeds.

Magnesium

Magnesium is an extremely important mineral and works to activate many enzymes, muscles and nervous functions. Symptoms of deficiency may include muscle cramps, headaches, loss of appetite, insomnia and a predisposition to stress.

How can I get it?
Magnesium occurs abundantly in whole foods and the best dietary sources are kelp, seaweeds, citrus fruits, green leafy vegetables such as broccoli, cabbage, nuts, wholegrains and tofu.

Chromium

Chromium is vital to the Glucose Tolerance Factor (GTF) - a critical enzyme system that works with insulin to absorb glucose into cells, regulating blood sugar levels. Chromium levels can be depleted by over-consuming refined sugars and white flour products and lack of exercise.

How can I get it?
The best sources are brewer's yeast, wholegrains, potatoes, apples, parsnips and bananas.

Iron

Iron is critical to human life. It plays the central role in the haemoglobin molecule of our red blood cells, where it works transporting oxygen from the lungs to the body's tissues and taking carbon dioxide from the tissues to the lungs. In addition, Iron functions in several key enzymes in energy production and metabolism including DNA synthesis. Iron deficiency is the most common deficiency worldwide and can lead to anaemia.

How can I get it?
A portion of red meat or sardines served with a dark green leafy vegetable such as kale will meet the RDA. Other good sources include offal, egg yolk and fortified cereals.

Selenium

Selenium works with vitamin E in preventing free radical damage to cell membranes. It is important for a healthy immune system, fertility and thyroid metabolism. It also helps to regulate blood pressure.

How can I get it?
A few Brazil nuts or a prawn sandwich made with wholemeal bread would provide the daily intake. Other good sources include offal, shellfish, butter, avocados and wholegrains.

Zinc

Zinc is part of more than 200 enzymes in our bodies. In fact, zinc functions in more reactions than any other mineral. Adequate zinc levels are needed for proper immune function and zinc deficiency results in an increased susceptibility to infection. It is essential for the maintenance of vision, taste and smell.

How can I get it?
Zinc is found in fish, shellfish, lean red meat, seeds, nuts, legumes and wholegrains.

Potassium

Potassium can help your muscles and nerves to function properly, lower your risk of high blood pressure and heart problems, ease fatigue, irritability and confusion. Older people are more at risk of too much potassium in the body as their kidneys are less able to eliminate excess.

How can I get it?
Potassium is found in many foods, and is especially easy to obtain in fruits and vegetables such as chard, mushrooms and spinach.

Sodium

Sodium is a component of salt, which is naturally present in the majority of foods we eat. Most people eat more salt than is good for their health. It is recommended that adults eat no more than 6g of salt (equivalent to 2.5g of sodium) per day. Three quarters of our salt consumption comes from packaged foods such as breakfast cereals, soups, sauces and ready meals.
 

UK dietary recommendations

Dietary recommendations for any nutrient are based on the daily intake thought to be adequate to safely satisfy the needs of the majority of the population. Despite much research, values for optimum intakes are still being debated. The Reference Nutrient Intake (RNI) measure used in the UK, is calculated from studies of the physiological requirements of healthy people, but because these studies are subject to wide interpretation, the RNI value for a nutrient can vary from country to country. Recommended Daily Allowances (RDAs) are said to apply to 'average adults' and are only very rough guides.

Nutritional requirements often vary slightly for specific groups of the population, during pregnancy and old age for example. It is wise to check with your doctor about how much you need.