Micronutrients Food a fact of life 2009 Extension

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Micronutrients © Food – a fact of life 2009 Extension

Micronutrients © Food – a fact of life 2009 Extension

Learning objectives • To understand the importance of micronutrients. • To recognise the difference

Learning objectives • To understand the importance of micronutrients. • To recognise the difference between water-soluble and fat-soluble vitamins, major minerals and trace elements. • To learn the functions and sources of the micronutrients. • To learn the problems caused by malnutrition. • To understand some interactions between nutrients. © Food – a fact of life 2009

Micronutrients are needed in much smaller amounts than the macronutrients. There are two types

Micronutrients are needed in much smaller amounts than the macronutrients. There are two types of Micronutrients: vitamins and minerals In general micronutrients are needed to regulate the maintenance and growth of the body, and to control metabolic reactions in cells. . © Food – a fact of life 2009

Vitamins There are two groups of vitamins: • fat-soluble vitamins, which can be stored

Vitamins There are two groups of vitamins: • fat-soluble vitamins, which can be stored in the body, e. g. vitamins A and D. • water-soluble vitamins, which cannot be stored in the body and are therefore required daily, e. g. B vitamins and vitamin C. © Food – a fact of life 2009

Vitamin A (retinol, carotene) Vitamin A is fat-soluble vitamin needed for the normal structure

Vitamin A (retinol, carotene) Vitamin A is fat-soluble vitamin needed for the normal structure and functioning of the cells in the skin and body linings, e. g. in the lungs. This vitamin also helps with vision in dim light, as well a keeping the immune system healthy. It is found in two forms; retinol in foods from animal sources and carotenoids (the most abundant of which is the betacarotene) from plant sources. Vitamin A – retinol is found in liver and whole milk, Vitamin A – carotenoids are found in dark green leafy vegetables, carrots and orange coloured fruits. © Food – a fact of life 2009

Too much or too little? Deficiency leads to poor vision in dim light or

Too much or too little? Deficiency leads to poor vision in dim light or night blindness. Severe deficiency can lead to total blindness. Vitamin A is stored in the liver and too much vitamin A can be toxic. Consuming too much vitamin A whilst being pregnant has been linked to birth defects. © Food – a fact of life 2009

Vitamin D (Cholecalciferol) Vitamin D is needed for the absorption of calcium and phosphorous

Vitamin D (Cholecalciferol) Vitamin D is needed for the absorption of calcium and phosphorous from foods, to keep bones healthy. Recent research also suggests that vitamin D enhances immune function and improves muscle strength. Vitamin D is found in the diet, but most of our vitamin D is made in the body the action of ultra violet rays on the skin. Vitamin D occurs naturally in some animal products, including fish liver oils, oily fish, egg yolk, and butter. Cereals, margarine and low fat spreads are also fortified with vitamin D. © Food – a fact of life 2009

Too much or too little? Deficiency of vitamin D leads to rickets and the

Too much or too little? Deficiency of vitamin D leads to rickets and the formation of soft bones. This causes the bones in the legs to bend. Deficiency in adults causes Osteomalacia resulting in pain and muscular weakness. Vitamin D can be stored by the body. Too much vitamin D can lead to excess levels of calcium in the blood. Young children, housebound older adults, and people who practice religions where their skin must be covered, may be at risk of deficiency through lack of exposure of their skin to sunlight. © Food – a fact of life 2009

Vitamin E (Tocopherol) Vitamin E is a group of similar molecules with common properties

Vitamin E (Tocopherol) Vitamin E is a group of similar molecules with common properties and functions. Vitamin E acts as an antioxidant and protects cells in the body against damage. Vitamin E is mainly found in vegetable oils, nuts, seeds and wheat germ. © Food – a fact of life 2009

Deficiency and excess of vitamin E A deficiency in this vitamin is rare because

Deficiency and excess of vitamin E A deficiency in this vitamin is rare because it is so widely available in the diet. In very rare cases neurological disabilities such as lost reflexes have developed. Vitamin E has a low toxicity, but in very large doses may interfere with absorption of vitamin A. © Food – a fact of life 2009

Vitamin K is needed for normal clotting of blood and is also required for

Vitamin K is needed for normal clotting of blood and is also required for normal bone structure. Infants are given vitamin K at birth. Vitamin K is also produced by the bacteria in the gut. Vitamin K is found in green leafy vegetables e. g. broccoli, lettuce, cabbage, spinach and meat and dairy products. © Food – a fact of life 2009

Too much or too little? Deficiency of vitamin K is rare in adults, but

Too much or too little? Deficiency of vitamin K is rare in adults, but is sometimes seen in new born babies. © Food – a fact of life 2009

Vitamin B 12 is needed for the formation of red blood cells and the

Vitamin B 12 is needed for the formation of red blood cells and the normal functioning of the nervous system. Vitamin B 12 also helps to release energy from food. Vitamin B 12 is found exclusively in animal products, plant products do not provide any vitamin B 12. It is found in meat, fish, cheese, eggs, yeasts extract and fortified breakfast cereals. © Food – a fact of life 2009

Deficiency of vitamin B 12 can lead to pernicious anaemia. It can also lead

Deficiency of vitamin B 12 can lead to pernicious anaemia. It can also lead to some neurological problems. Deficiency is rare, but may be a problem for people following strict vegan or vegetarian diets. © Food – a fact of life 2009

Folate (Folic acid) Folate is important for the formation of healthy red blood cells.

Folate (Folic acid) Folate is important for the formation of healthy red blood cells. It is also needed for the nervous system and specifically for the development of the nervous system in unborn babies. It can reduce the risk of neural tube defects in a fetus, e. g. spina bifida. Good sources of folate include green leafy vegetables brown rice, peas, oranges, bananas and fortified cereals. © Food – a fact of life 2009

Deficiency of folate can lead to megaloblastic anaemia. Symptoms can include insomnia, depression and

Deficiency of folate can lead to megaloblastic anaemia. Symptoms can include insomnia, depression and forgetfulness. It is recommended that all women who are planning a pregnancy take a daily supplement of folic acid. Once pregnant, supplementation should continue for the first 12 weeks to reduce the risk of neural tube defects. © Food – a fact of life 2009

Vitamin C (Ascorbic acid) Ascorbic acid is needed to make collagen which is required

Vitamin C (Ascorbic acid) Ascorbic acid is needed to make collagen which is required for the normal structure and function of body tissues, such as skin, cartilage and bones. It also acts as an antioxidant that protects the body from damage by free radicals. Sources of ascorbic acid include fresh fruits, especially citrus fruits and berries, green vegetables, peppers and tomatoes. Ascorbic acid is also found in potatoes (especially in new potatoes). © Food – a fact of life 2009

Too much or too little? Scurvy can result from lack of ascorbic acid. It

Too much or too little? Scurvy can result from lack of ascorbic acid. It tends to occur in infants and the older adults. Scurvy leads to spots on the skin, bleeding gums and loose or loss of teeth. Over nutrition of ascorbic acid is rare. © Food – a fact of life 2009

Minerals are inorganic substances needed by the body for many different functions. Some minerals

Minerals are inorganic substances needed by the body for many different functions. Some minerals are needed in very tiny amounts, these are known as trace elements, such as fluoride. © Food – a fact of life 2009

Calcium (Ca) Calcium is important for the formation and maintenance of strong bones and

Calcium (Ca) Calcium is important for the formation and maintenance of strong bones and teeth, as well as the normal functioning of nervous system and muscles. It is also involved in blood clotting. Milk and dairy products are the most important sources of calcium. Other sources include bread, calcium enriched soya products, green leafy vegetables and fish with soft edible bones. © Food – a fact of life 2009

Too much or too little? Poor intakes of calcium can result in poor bone

Too much or too little? Poor intakes of calcium can result in poor bone health which can increase the risk of diseases such as osteoporosis later in life. Taking high doses of calcium supplements can cause stomach pains and diarrhoea. © Food – a fact of life 2009

Iron (Fe) Iron is needed for the formation of haemoglobin in red blood cells

Iron (Fe) Iron is needed for the formation of haemoglobin in red blood cells which transport oxygen around the body. It is also required for energy metabolism and has an important role in the immune system. Haem iron is present in animal sources in the form of haemoglobin. Non haem iron is present in plant sources such as beans, nuts, dried fruits, wholegrains, soya bean flour and dark green leafy vegetables. © Food – a fact of life 2009

Too much or too little? A lack of iron will lead to anaemia. Symptoms

Too much or too little? A lack of iron will lead to anaemia. Symptoms include: • • feeling of tiredness; lacking in energy; general weakness; poor concentration. Too much iron in the diet can result in constipation, nausea and vomiting. © Food – a fact of life 2009

Potassium (K) Potassium is essential for water and electrolyte balance and normal functioning of

Potassium (K) Potassium is essential for water and electrolyte balance and normal functioning of cells, including nerves. Potassium is present in all foods, but found richly in fruit (dried fruits, bananas, berry fruits), leafy green vegetables (e. g. broccoli and spinach) meat, nuts, seeds and pulses. © Food – a fact of life 2009

Sodium (Na) Sodium is needed to regulate body water content and electrolyte balance. Sodium

Sodium (Na) Sodium is needed to regulate body water content and electrolyte balance. Sodium is also needed for the absorption of some nutrients and water from the gut. Sodium is present in very small amounts in raw foods. It is often added as salt during processing, preparation, preservation and serving. High salt processed foods include bacon, cheese, yeast extract and smoked fish. © Food – a fact of life 2009

Too much or too little? Consuming too much sodium increases the risk of high

Too much or too little? Consuming too much sodium increases the risk of high blood pressure. High blood pressure is linked with an increased risk of heart disease and stroke. Sodium deficiency is unlikely, but can be caused by excessive sweating or vomiting and diarrhoea. It is recommended that adults and children over the age of 11 years cut down on salt and consume no more than 6 g per day. © Food – a fact of life 2009

Fluoride (F) Fluoride is needed for the formation of strong teeth and protects against

Fluoride (F) Fluoride is needed for the formation of strong teeth and protects against dental decay (caries). Fluoride is a trace element, therefore only a small amount is required for good health. Fluoride can be found in drinking water and in small amounts in tea and saltwater fish. Some areas add fluoride to the drinking water. Fluoride toothpastes are another important source. © Food – a fact of life 2009

Too much or too little? An excessive intake of fluoride can lead to mottling

Too much or too little? An excessive intake of fluoride can lead to mottling or discolouration of teeth. © Food – a fact of life 2009