Trace minerals

Trace minerals, otherwise known as microminerals or trace elements, as you might guess, are minerals that you only require in very small amounts.  They are mostly plentiful in natural foods.  However, there has been interest in whether deficiency may occur, and whether supplementation can be beneficial for some people.


Why do we need it?

Where do we find it?

Iron (Fe)

To transfer oxygen between tissues in our body.  Most iron in our body is in haemoglobinin blood cells or myoglobin in muscle (two proteins that carry oxygen).

 Iron is also essential for a healthy immune system and in some enzymes.

Deficiency is common, especially in young people and menstruating women.

Best absorbed is ‘haem iron’, present in meat and fish.

 ‘Non-haem iron’, in plant foods such as cereals, is less well absorbed.  There is very little in vegetables like spinach!

Vitamin C improves the absorption absorption of non-haem iron.

Zinc (Zn)

Needed for the function of many enzymes in our body, for function of the immune system, blood clotting (healing of wounds), growth and repair of tissues.

Deficiency in humans only occurs with malnutrition and with extra losses (e.g. diarrhoea, leg ulcers).

Many sources include red meat, liver, dairy products, whole grain products, eggs, fish, shellfish, beans, nuts and seeds.

 As with iron, zinc is absorbed easier from animal than from plant sources.

Chromium (Cr)

Involved in blood glucose regulation and the action of insulin, but deficiency is virtually unknown, and not responsible for diabetes.

Deficiency in humans only with severe intestinal failure.

Widely present in foods, eg meats, whole-grain products, and nuts.

Cobalt (Co)

Required as part of vitamin B12, for the formation of red blood cells and the function of the nervous system and brain.

Probably no dietary deficiency in humans, though vitamin B12 deficiency is seen.

Sources include liver, kidney, meats, and dairy products.

Large bowel bacteria are needed to extract cobalt and make vitamin B12

Copper (Cu)

Needed in minute amounts to form red blood cells, but in larger amounts interferes with iron.

Also a component of many enzymes.

Deficiency in humans only with serious illness and intestinal failure.

Rich sources are liver, kidney, shellfish, nuts and whole-grain cereals.

Fluoride (F)

Needed to form and to maintain our teeth, and to prevent tooth decay.

Deficiency in humans is common in areas with low fluoride in the mains drinking water.

Humans need about 1ppm (part per million) of fluoride in drinking water.

Tea is a very rich source.

Iodine (I)

Essential part of thyroid hormones which regulate metabolism, growth and development.

Deficiency in humans common in areas with low iodine soil and in people with low diary and sea-food consumptions.

Main sources are sea-foods, and milk and dairy foods

Also, iodine can be used to sterilise milking machines.

Salt is sometimes iodised.

Manganese (Mn)

Component of some enzymes, including those that break down carbohydrates and cholesterol.

 Deficiency in humans only with severe intestinal failure

Wholegrain cereals, nuts, pulses, berries, beans, vegetables and tea.

Molybdenum (Mo)

Component of some enzymes including those that break down proteins.

Deficiency unknown in humans.

Virtually all foods..

Selenium (Se)

Component of some enzymes, for healthy heart function, for thyroid hormone synthesis and associated with vitamin E activity

In larger amounts it becomes toxic.

Deficiency in humans is currently debated; may cause heart failure.

Present in virtually all foods, especially  cereals, meat, fish, dairy products (e.g. eggs) and Brazil nuts.  Problems as a toxic contaminant as fall-out from factories.