Micronutrients are no small topic

Matt Whitaker – Researcher and Trainer in Public Health/18 October 2018

The food we consume is broken down into macronutrients, micronutrients, water and fibre. Micronutrients are required in trace amounts for the normal growth, development and functionality of humans. They are subcategorised into vitamins and minerals. Ensuring consumption of adequate amounts of these nutrients is vital for the sustainability of a healthy life. All foods contain a variety of micronutrients; some are higher in certain micronutrients.

This blog will introduce different micronutrients, their function and foods they are commonly found in.

Most vitamins required for essential bodily functionality need to be sourced from the diet. There are 13 in total which are categorised as either fat or water soluble. All vitamins have different functionalities and are required in ranging quantities. If you overconsume water soluble vitamins they are simply excreted out, if you overconsume fat soluble vitamins they are stored in fat for later use.

Water soluble vitamins include:

Thiamine (B1). This is important for nerve functioning and in metabolism. Foods rich in B1 include pork, wholegrain breads and cereals, legumes, nuts and seeds.

Riboflavin (B2). Again used in metabolism and also for sight and skin health. B2 is found in leafy vegetables, dairy products and wholegrain carbohydrates.

Niacin (B3). Use in metabolism, nervous system, digestion and skin health. B3 is found in most meat, poultry and fish, wholegrain carbohydrates and green leafy vegetables.

Panthothenic acid, biotin and pyridoxine (B6). These are found in a variety of foods, particularly meats, fish and vegetables. They all play a part in maintaining metabolism and in red blood cell production.

Folic acid. This is used in the creation of DNA and new cells. It is often added to fortified carbohydrates and is naturally found in leafy vegetables and legumes.

Vitamin C. This is an antioxidant required for protein metabolism, the body’s immune response and iron absorption. Foods high in vitamin C include: fruits, particularly citrus and vegetables.

Fat soluble vitamins include:

A. This helps form and maintain teeth, bones, soft tissues and skin. This is found in dairy products, eggs, liver and vegetables.

D. This is required for calcium absorption. Dietary sources include egg yolks, liver, fish, additionally you can absorb vitamin D from sunlight.

E. This is an antioxidant which protects the integrity of cell walls. Dietary sources include, leafy vegetables, wholegrain products, liver, eggs, nuts and seeds.

K. This is required to prevent blood clotting. It is found mostly in green vegetables.

Minerals are essential for the functionality and development of our bodies. Particularly at times of growth, when pregnant and breastfeeding. They cannot be made within the body so must be sourced from external sources.

Minerals include:

Calcium.

Required for the maintenance of healthy bones and teeth, additionally it is essential in metabolism, the nervous system and muscle contractions. Dietary sources include: dairy products, green vegetables and fish with bones in it e.g. tinned.

Phosphorus.

This mineral is used alongside calcium in the maintenance of bone and teeth health. It is also essential in cell membrane structure. Phosphorus is found in red meat, dairy, fish, poultry and wholegrain carbohydrates.

Magnesium.

This is present in all human tissue, particularly in bone. It is essential in the activation of DNA replication, nerve functioning, hormone production and bone metabolism. It is mostly found in green vegetables, nuts, fish, meat and dairy products.

Sodium.

This mineral is responsible for fluid and electrolyte balance. High sodium levels are concerned to be associated with hypertension, a topic discussed in a previous blog. Often we add salt to foods as a flavour enhancer. It is also added as a preservative to many processed foods to extend shelf life.

Potassium.

This mineral is also essential in regulating water and electrolyte balance. Potassium may be cardio protective and is also used for the functioning of cells and nerves. Foods rich in potassium include: vegetables, meat, fish, shellfish, nuts, seeds, dairy and fruit (particularly bananas).

Iron.

This mineral forms haemoglobin in red blood cells; binding oxygen and transporting it around the body. It is also used in energy metabolism and the removal of foreign substances from the body. Haem iron is found in animal sources and non-haem found in plant sources. Foods high in iron include: in liver, red meat, pulses, nuts, eggs, poultry, wholegrains and leafy vegetables.

Zinc.

This mineral is important in cellular division, growth and tissue repair, it is also used to maximise an immune system response and in skin structure. Zinc is found in meat, dairy, cheese, eggs, shellfish, nuts and wholegrain cereals.

Iodine.

This is important in physical and mental development and the maintenance of metabolic rate. Dietary sources include: vegetables, cereal grains, oily fish, seaweed and milk.

Fluoride.

This is important in dental health and hygiene through the mineralisation of bones and teeth. Fluoride is often added to toothpaste and is also found in tea and fish.

Copper.

This is used in the production of white and red blood cells and in the utilisation of iron. Copper is particularly important in infant growth- aiding in brain development, immune system development and bone growth. Dietary sources include: shellfish, liver, kidney, nuts and wholegrain cereals.

Selenium.

This mineral protect against oxidative damage, used in thyroid production, immune system function and reproductive functioning. Dietary sources include: Brazil nuts, bread, fish, meat and eggs.

Manganese.

This is used in bone formation and energy metabolism. It also helps to prevent free-radical damage to cells. It is found in most vegetables, cereals, tea and nuts.

Chromium.

This is involved in carbohydrate and lipid metabolism and promotes the action of insulin. Those who have higher intakes may see improved glycaemic control. Dietary sources include: meat, nuts, wholegrain cereals and yeast.

Conclusion

All micronutrients can be sourced from the diet. Despite this, some may elect the use of supplements, particularly multivitamins to help prevent deficiencies. It is suggested that these supplements are not as bioavailable (easily absorbed) as vitamins and minerals found from dietary sources. Therefore they should only be considered if prescribed e.g. iron for anaemia. Spending large amount of money of supplements is often wasted. The majority of the excess vitamins and minerals will be excreted out in the urine.

Dietary sources of micronutrients tend to be ‘real foods’ with no processed food being a good source of any particular vitamin or mineral. Consuming a diverse diet with an emphasis on unprocessed foods and minimal snacking will minimise the risk of any micronutrient deficiency.