We need all vitamins and minerals for good health, well being and energy. However, particular nutrient deficiencies are associated with reduced energy and chronic tiredness. These include iron, magnesium, B12 and folic acid. We will explore each of these nutrients; how they contribute to tiredness; how to test their levels in the body; and symptoms of a deficiency

Iron is an essential mineral needed for the manufacture of haemoglobin, the part of red blood cells that carries oxygen and is needed for energy production. When iron levels are low, red blood cells can’t carry enough oxygen to the body’s tissues, causing fatigue. When haemoglobin levels are low, anaemia occurs.

There are two types of iron: haem iron (from animal sources) and non-haem iron (from plant sources). The body absorbs haem iron much more easily than non-haem iron, which is why vegetarians are at greater risk of iron-deficiency anaemia.

Symptoms of deficiency: fatigue (especially on exertion); pale lower eyelids, palms, nails, tongue; brittle nails; headaches; constipation; inflamed tongue.

Testing for deficiency: iron levels are tested easily with blood samples. Serum iron – tests iron levels in the blood. Ferritin levels – test how well iron is stored in the body, the best indicator of the body’s iron levels.

Caution: Excess iron absorption (called haemochromatosis) also causes chronic tiredness so it’s important to check your iron levels before using an iron supplement.

Vitamin B12

Vitamin B12 is needed for manufacture of red blood cells (along with folic acid). B12 helps the body’s use of iron and is also required for proper digestion, the absorption of foods, the synthesis of protein and the metabolism of carbohydrates and fats. No wonder it’s important for good energy levels! It is often observed that taking B12 (especially via injections) reduces fatigue, even when a deficiency isn’t found.

B12 deficiencies are common due to declining B12 levels in food, increased use of antibiotics and digestive problems. This is because B12 is produced in the digestive tract as well as being absorbed from food. Those most at risk of a B12 deficiency are vegetarians and people with digestive disturbances.

Symptoms of deficiency: fatigue, weakness, dizziness, sore tongue, memory problems, confusion, irritability, depression, moodiness, paleness.

Testing for deficiency: B12 levels can be measured with a blood test

Folic acid is a B vitamin (also called B9 or folate) needed for the manufacture of red blood cells. Deficiency can lead to a condition called megaloblastic anaemia. Fatigue is associated with both a simple folic acid deficiency as well as megaloblastic anaemia. Because folic acid is easily destroyed during cooking, it is one of the most common vitamin deficiencies.

Symptoms of deficiency: similar to those of B12, including fatigue, digestive disturbances, insomnia, memory problems, weakness, shortness of breath, recurrent miscarriages, mental confusion, paranoid delusions, sore tongue, anaemia.

Testing for deficiency: folic acid levels can be measured with a blood test.

Caution: if folic acid is given to someone who is B12 deficient and B12 isn’t given at the same time, the symptoms of a B12 deficiency (especially neurological symptoms) can be masked. Only take folic acid if a B12 deficiency has been ruled out.

Magnesium is needed for the production of ATP, which is the main energy-producing molecule in the body. Therefore, when magnesium is deficient our cells are less able to produce energy and we can experience chronic tiredness. It has been found that nearly all people with chronic fatigue syndrome are magnesium deficient and for about 80 per cent of people given magnesium their energy improves. In fact, magnesium is the most common nutrient deficiency in all people. Most of us would benefit from supplementation even if magnesium levels are unable to be checked.

Symptoms of deficiency: fatigue, irritability, muscle spasms or cramps, rapid or irregular heartbeat, high blood pressure, insomnia.

Testing for deficiency: magnesium is not generally tested by blood test. Hair analysis is the most readily available test. Hair mineral levels are a measure of the minerals bound into the hair shaft over a period of time and correlate most closely with tissue levels. The hair analysis test can be performed through specialist laboratories.

Caution: if magnesium supplements worsen your symptoms (especially cramping, twitching and muscle spasms), calcium is probably the deficiency, not magnesium.