Minerals - the body's requirement

How do minerals help keep us healthy? Where should we get them from? And are there health risks if we take too much?

Do our bodies need minerals?

Minerals are vital for our health. They work behind the scenes, in small quantities, to keep our bodies healthy and functioning. For instance calcium (with Vitamin D) helps build strong bones and teeth; iron carries oxygen to all parts of our body (and without it we start to feel anaemic); magnesium keeps nerves and muscles strong; potassium helps control blood pressure; and zinc helps maintain our body’s immune system.

Our bodies need different amounts of each mineral. We also have different requirements, depending, for example, on how old we are, whether we’re male or female and our physiological state (e.g. if we’re pregnant or sick in any way), which may affect how our bodies process minerals – and sometimes mean we need more.

Where should we get our minerals from?

Our bodies don’t make minerals. So we need to get minerals from the food we eat. And different foods contain different minerals. That means we need to eat a varied diet to make sure that we’re getting enough minerals. Vegetables, fruit, grains and pulses are good sources of minerals, absorbed from the soil.

Medical advice is usually to get your minerals from food rather than from supplements. That’s because there can be health risks if you consume too much of certain minerals. There often seems to be what is called a U curve effect i.e. too much or too little of a mineral may increase health risks. For example low levels of selenium are associated with an increased risk of death, poor immune function and cognitive decline - but taking a selenium supplement if you already have an adequate selenium intake from your diet can increase the risk of type 2 diabetes.

The mineral content in food seems to have declined over the years, as a result of both soil depletion and the development of high yield vegetables and fruit (which tend to have more carbohydrate and fewer minerals and other micronutrients). However a Canadian review, published in 2017, concluded that reductions in mineral levels are not significant and are offset by higher yields from crops.

Consult your doctor if you are concerned about possible vitamin deficiency and they can advise you.

Eight important minerals reviewed 

Mineral

Main Food Sources

Comments

Sodium

Salt (i.e sodium chloride) is added to many processed foods such as: ready meals, bacon, sausages, some breakfast cereals, cheese and bread. 

Our bodies need salt to help keep the level of fluids in the body balanced. However, salt deficiency is unusal because so much is added to processed food. So, unlike many other minerals, we are advised to reduce our salt intake. Too much salt is linked to an increase in blood pressure, which raises your risk of a stroke and heart attack.  

Potassium

 

Meat, fish, shellfish , fruit (like bananas), vegetables, pulses, milk, nuts and seeds.

Potassium helps control the balance of fluids in the body and possibly helps lower blood pressure. It is important for the way the body’s cells and organs function. A low level of potassium is associated with increased risk of blood pressure.

Magnesium

 

Whole grains, dark green vegetables, brown rice, nuts (like almonds, brazil nuts, cashews and peanuts) , seeds, fish, meat and dairy products.

Magnesium helps turn the food we eat into energy. It is required by all organs in the body. Magnesium deficiency is rare. Excessive magnesium consumption from supplements can cause side effects, like stomach upsets and diarrhea – and should be avoided  if you have kidney problems.

Manganese

 

Tea, whole grains, nuts, green leafy vegetables and cereals. 

 

Manganese helps make and activate some of the enzymes in the body. It is required for wound healing, bone development and nutrient absorption. Manganese deficiency is rare. Taking high doses of manganese for long periods of time might cause muscle pain, nerve damage, fatigue or depression.

Iron

 

Liver, meat, fortified cereals, dried fruit, dark green leafy vegetables, fortified breakfast cereals, beans and nuts(like almonds, cashews and peanuts – ideally unsalted and unroasted to limit the salt content).

Lack of iron can lead to anaemia.Symptoms include lack of energy, shortness of breath and heart palpitations.Don’t drink tea with food, as this can reduce iron absorption.Women who experience heavy periods  may need to take iron supplements. Check with your GP.However, too much iron in the body leads to iron overload— which can damage organs such as the liver, heart and pancreas. So take iron supplements only if recommended by your doctor.

Selenium

 

If you eat meat, seafood and nuts (particularly brazil nuts) you should be able to get all the selenium you need from your daily diet.

Selenium is important for our immune system and for reproduction. It also helps prevent damage to cells and tissues. Selenium deficiency can lead to the development of Keshan disease ( a potentially fatal disease of the heart muscle). Too much selenium can lead to loss of hair, skin and nails – and in very high doses potentially more serious consequences, including heart attack.

Copper

 

Nuts, shellfish, offal.

Copper is thought to be important for brain development, our immune system and strong bones. Copper deficiency can cause anaemia and neutropenia (an abnormally low level of a type of white blood cell that helps fight infection).However, too much copper consumed over a long time can cause damage to our liver and kidneys. 

Zinc

 

 

 

Shellfish (especially oysters), meat, seeds, shiitake mushrooms, wheat germ, spinach, asparagus, nuts, quinoa, oats.

Zinc is important for growth, for health and the body’s immune system and for wound healing.Zinc deficiency can lead to loss of appetite and impaired immune function. In more severe cases symptoms can range from impotence to skin and eye lesions.Taking high doses of zinc reduces the amount of copper the body can absorb. This can lead to anaemia and weakening of the bones. 

The British Nutrition Foundation provides detailed guidance on nutritional requirements for minerals by age and gender. 

Conclusions

  • We need to eat a varied diet, to ensure we get all the minerals we need to help maintain our health.
  • Unless advised by our doctor, we should normally avoid mineral supplements – as having too much of a mineral is usually bad for our health too.
  • Soil depletion and the development of high yield foods lower in micronutrients mean we may need to eat more healthy food than our grandparents to achieve the same health benefits.

Reviewed and updated by Isobel Morgan, January 2018. Next review date December 2020.

Vitamins and Minerals

Vitamins and Minerals

Eating well as you get older