Nutrition and Health Micronutrients Vitamins Topics Vitamins Watersoluble

Nutrition and Health Micronutrients - Vitamins

Topics • Vitamins • Water-soluble vitamins – vitamin B – vitamin C • Fat-soluble vitamins – vitamin A – vitamin D – vitamin E – vitamin K 2

VITAMINS 3

Vitamins • Vitamins are micronutrients • They are natural substances found in foods that have different functions in the human body • The human body needs them in very small quantities • Vitamins are essential for good health and growth • There are two groups of vitamins – water-soluble vitamins – fat-soluble vitamins 4

WATER-SOLUBLE VITAMINS 5

Water-Soluble Vitamins • Water-soluble vitamins dissolve in water • The excess water-soluble vitamins from intake will be excreted through urination and cannot be stored in the body • Therefore, foods rich in these vitamins need to be consumed regularly • Water-soluble vitamins are heat-unstable, and can be lost upon heat treatment of food • Water-soluble vitamins include: - vitamin B complex (thiamine, riboflavin, niacin, pyridoxine, folate, cobalamin) - vitamin C 6

Water-Soluble Vitamins Functions Vitamin B 1 (Thiamine) • Vitamin B 2 (Riboflavin ) Vitamin B 3 (Niacin) • • Sources Deficiency Cereals, meat, liver, milk and dairy products, eggs and vegetables (including potatoes) • Cereals, milk and dairy products, meat, liver, kidney, eggs, green vegetables • Involved in the energy Meat (especially producing reactions offal), cereals, Helps in maintaining potatoes, bread healthy nervous system and skin • Helps the release of energy from nutrients Needed for healthy skin Helps release energy to cells and in the body’s use of carbohydrates ** Source: British Nutrition Foundation • • Reference Nutrient Intakes (RNI) ** for adults per day Shortage slows growth and development Mild deficiency causes tiredness and depression Severe deficiency causes beri • • • Men: 1. 0 mg Women: 0. 8 mg Increase intake during pregnancy and lactation Shortage slows growth and development May cause skin and eye problems • • • Men: 1. 3 mg Women: 1. 1 mg Increase intake during pregnancy and lactation Severe deficiency causes pellagra Symptoms include diarrhoea, dementia and dermatitis • • • Men: 17. 0 mg Women: 13. 0 mg Increase intake during pregnancy and lactation 7

Water-Soluble Vitamins Functions Vitamin B 6 (Pyridoxine) • Vitamin B 9 (Folate) • • Sources Deficiency Reference Nutrient Intakes (RNI) ** for adults per day Needed for the metabolism of protein Helps formation of red blood cells and proper functioning of the nervous system Liver, kidney, fish, • wheat germ, poultry, leafy vegetables, potatoes, cereals Rare, but deficiency in infants can cause convulsions Needed for red blood cell production Cereals, nuts and pulses, leafy vegetables (such as spinach) Mild deficiency leads • to tiredness • A folate deficiency can cause megaloblastic • anaemia Deficiency in the early stages of pregnancy is associated with neural tube defects in foetus • • • ** Source: British Nutrition Foundation • • Men: 1. 4 mg Women: 1. 2 mg 200 µg Increase intake during pregnancy and lactation Woman planning pregnancy, or in the first 12 weeks, should supplement their diet with 0. 4 mg per day 8

Water-Soluble Vitamins Functions Vitamin B 12 (Cobalamin) • Vitamin C (Ascorbic Acid) • • • Sources Deficiency Helps prevent certain forms of anaemia Helps cells divide Protects nervous system All animal foods – liver, fish, meat, cheese, milk, eggs • Deficiency can lead to pernicious anaemia and neurological problems • 1. 5 µg Maintains body’s connective tissue, important for wound healing Helps iron absorption Has antioxidant properties Fruits and vegetables, especially citrus fruits (including oranges and lemons) • Deficiency may cause • scurvy 40 mg ** Source: British Nutrition Foundation Reference Nutrient Intakes (RNI) ** for adults per day 9

VITAMIN B 10

Vitamin B • Scientists originally thought there was only one vitamin B, but then discovered that there were several more that had similar functions in the body • They are all grouped together and are known as the “vitamin B complex”, such as - vitamin B 1 (thiamine) - vitamin B 2 (riboflavin) - vitamin B 3 (niacin) - vitamin B 6 (pyridoxine) - vitamin B 9 (folate) - vitamin B 12 (cobalamin) 11

Functions of Vitamin B 1 (Thiamine) • Helps release energy from carbohydrates • Helps the body grow • Helps the nerves work properly 12

Sources of Vitamin B 1 (Thiamine) • Vitamin B 1 is not stored in the body, so a continuous daily supply is needed • Foods that provide vitamin B 1 : – cereals such as wheat and rice (especially whole grain) and cereal products – meat (especially pork, bacon and ham) and offal (especially liver, kidney and heart) – eggs, fish roe – milk and dairy products – seeds, nuts, beans 13

Deficiency of Vitamin B 1 (Thiamine) • Deficiency of vitamin B 1 can cause beri A diet low in thiamine Beriberi Dry beri Wet beri Affects the heart and circulatory system, and can cause heart failure Damages the nerves and can lead to decreased muscle strength and eventually, muscle paralysis 14

Beriberi A diet with a good supply of vitamin B 1 Adopt a balanced diet Prevention of beri 15

Functions of Vitamin B 2 (Riboflavin) • Helps release energy from carbohydrates, fats and proteins • Needed for growth in children 16

Sources of Vitamin B 2 (Riboflavin) • Foods that provide vitamin B 2: – cereals such as wheat and rice (especially whole grain) and cereal products – meat (especially pork, bacon and ham) and offal (especially liver, kidney and heart) – eggs, fish roe – milk and dairy products – seeds, nuts, beans 17

Deficiency of Vitamin B 2 (Riboflavin) • Low intake can lead to dryness and peeling skin on the nose, cracks and redness at the corners of mouth, and a swollen tongue • It affects vision, including blurred vision, sensitivity to light, itchy and watering eyes 18

Functions of Vitamin B 3 (Niacin) • Helps release energy from food • Used to lower the levels of fat in the blood 19

Sources of Vitamin B 3 (Niacin) • Foods that provide vitamin B 3: – cereals such as wheat and rice (especially whole grain) and cereal products – meat (especially pork, bacon and ham) and offal (especially liver, kidney and heart) – eggs, fish roe – milk and dairy products – seeds, nuts, beans • Although the liver can synthesise niacin from tryptophan (a kind of amino acid), the speed is extremely slow 20

Deficiency of Vitamin B 3 (Niacin) • Deficiency of vitamin B 3 can cause pellagra • The symptoms of pellagra are known as the three D’s: – Diarrhoea – Dermatitis (rough and sore skin) – Dementia (confusion, memory loss, unable to speak properly) 21

Excess of Vitamin B 3 (Niacin) • Very high dosage may cause liver damage 22

Functions of Vitamin B 6 (Pyridoxine) • Helps the body use protein, fat and carbohydrate • Involved in enzyme reactions and protein metabolism in the body 23

Sources of Vitamin B 6 (Pyridoxine) • Foods that provide vitamin B 6: – liver and kidney – poultry – fish – wheat germ, cereals – leafy vegetables – potatoes 24

Deficiency of Vitamin B 6 (Pyridoxine) • Vitamin B 6 deficiency is associated with: – headaches – general aching and weakness – anaemia 25

Excess of Vitamin B 6 (Pyridoxine) • High dosage may induce poor functioning of sensory nerves 26

Functions of Vitamin B 9 (Folate) • Folate is the natural form of the vitamin found in food, folic acid is the man-made vitamin in supplements and added to foods • Helps the body use protein • Important in making red blood cells • Involved in the synthesis and repair of DNA (deoxyribonucleic acid) in the body cells • Aids rapid cell division and growth, especially the cells in the bone marrow • Folate helps prevent the foetus from developing major congenital deformities of the brain or spine, including neural tube defects 27

Sources of Vitamin B 9 (Folate) • Foods that provide folate: – green and leafy vegetables (e. g. spinach and Chinese kale) – liver – fruits (e. g. oranges and berries) – asparagus, okra – beans (e. g. mung beans and red beans) and peas (e. g. chickpeas) 28

Deficiency of Vitamin B 9 (Folate) • Deficiency of folate can lead to a wide range of problems including: – effects in the digestive system, such as loss of appetite, nausea, diarrhoea and soreness in the mouth – megaloblastic anaemia Ø red blood cells are not fully mature and become larger and fewer than normal Ø therefore, not able to carry enough oxygen to body tissues – congenital deformities in foetus 29

Effects of Deficiency of Vitamin B 9 (Folate) in the Digestive System Inadequate intake of folate or folic acid Cells in the digestive system are not dividing properly Other nutrients are not absorbed Loss of appetite, nausea, diarrhoea and soreness in the mouth 30

Megaloblastic Anaemia Inadequate intake of folate or folic acid Red blood cells in the bone marrow are not dividing and mature properly Red blood cells become very large and are not able to deliver enough oxygen around the body Shortness of breath, muscle weakness, extreme tiredness, a lack of energy 31

Congenital Deformities in Foetus Very high demand of folate or folic acid during pregnancy (about 5 times more than normal) Pregnant women do not have adequate intake of folate or folic acid before conception Improper development of embryo during early stage of pregnancy Spina bifida occurs in foetus – a congenital deformity in the spine 32

Functions of Vitamin B 12 (Cobalamin) • Cobalamin is needed to form a protective coating around nerve cells to make them work properly • Important for the production of new cells 33

Sources of Vitamin B 12 (Cobalamin) • Cobalamin can be stored in the liver • Synthesised only by microorganisms • Therefore, only presents in animal foods; none in plant foods, such as – meat and liver – poultry and egg – fish – milk and dairy products 34

Deficiency of Vitamin B 12 (Cobalamin) • Prevents the nerves from working properly and leads to: – numbness or tingling, muscle weakness, and problem in walking – paralysis, memory loss and confusion • People who have problem absorbing cobalamin can develop pernicious anaemia – a condition in which the body does not have enough healthy red blood cells 35

VITAMIN C 36

Functions of Vitamin C (Ascorbic Acid) • Enable the body to absorb iron from food • For the production of collagen (a kind of protein) in the body • Collagen is the protein in connective tissue which is the substance that binds the body cells together • As an antioxidant which helps protect the body from polluting chemicals that get into the body – from the air, water or in food 37

Sources of Vitamin C (Ascorbic Acid) • Foods that provide vitamin C: – fruits, e. g. citrus fruits, kiwi fruit – vegetables, e. g. green, leafy vegetables (except for lettuce), broccoli, green peppers, potatoes • There is a very small amount of vitamin C in liver and fresh milk 38

Deficiency of Vitamin C (Ascorbic Acid) • A deficiency is rare but is occasionally found in the elderly and children who have very little fresh fruits and vegetables in their diet • Slight deficiency of vitamin C may cause anaemia because not enough iron is absorbed 39

Deficiency of Vitamin C (Ascorbic Acid) • A severe deficiency causes scurvy with the following symptoms: – bleeding gums – poor wound healing – damage to bone and other tissues 40

Deficiency of Vitamin C (Ascorbic Acid) Inadequate intake of vitamin C Anaemia Tiredness Inadequate formation of collagen Weakness Scurvy Bleeding gums Poor wound healing Damage to bone and other tissues 41

FAT-SOLUBLE VITAMINS 42

Fat-Soluble Vitamins • Fat-soluble vitamins dissolve in fats • The excess fat-soluble vitamins from intake will be stored in the body (liver and fatty tissue) • The body can retrieve these vitamins when needed, therefore, can consume less than daily need • Fat serves as a medium for the body to absorb these vitamins • Fat-soluble vitamins are relatively heat-stable as compared to water-soluble vitamins • Fat-soluble vitamins include: - vitamin A - vitamin D - vitamin E - vitamin K • Some fat-soluble vitamins can be easily oxidised, e. g. vitamin A and E 43

Fat-Soluble Vitamins Functions Vitamin A – retinol (animal origin) • Sources Deficiency Good for night vision, healthy skin and tissue Liver, oily fish, • whole milk, butter, margarine, cheese, eggs Vitamin A – • betacarotene (plant origin) Beta-carotene is an antioxidant vitamin which might protect against cancer Carrots, green vegetables, orange and red fruits and vegetables Vitamin D Works with calcium to • form healthy bones and teeth • • ** Source: British Nutrition Foundation The skin can make vitamin D after exposure to sunlight Margarine, oily fish, liver • Reference Nutrient Intakes (RNI) ** for adults Long-term deficiency • may lead to night • blindness Men: 700 µg Women: 600 µg Deficiency in children • can cause rickets 10 µg 44

Fat-Soluble Vitamins Functions Sources Deficiency Vitamin E • • Vitamin K • Good for healthy skin. May help protect against heart disease Eggs, nuts, seeds, cereal products, vegetable oils • Deficiency is rare, normally enough supply in a balanced diet • No RNIs but safe intakes have been set at more than 4 mg for men and more than 3 mg for women Involved with clotting of blood • Green • vegetables, pulses, fruits, cereals, meat, liver Also made by bacteria in the large intestine Deficiency is rare, normally enough supply in a balanced diet • No RNIs but safe intake is 1 µg per 1 kg body weight • ** Source: British Nutrition Foundation Reference Nutrient Intakes (RNI) ** for adults per day 45

VITAMIN A 46

Functions of Vitamin A • Helps the body grow and develop • Keeps the lining of the throat, the digestive system and the lungs moist and free from infection • Keeps the skin healthy • Makes a substance in the retina so the eyes can see well enough in dim light • As an antioxidant which helps stop substances that get into the body from the air, water and foods from damaging it 47

Sources of Vitamin A can be found in foods in two different forms: • Retinol is pure vitamin A – primarily found in animal sources that contain fat, e. g. milk, cheese, butter, oily fish (e. g. tuna, mackerel, sardines) and liver • Beta-carotene is a precursor of vitamin A – found in plant foods, e. g. carrots, oranges, red peppers, dark green leafy vegetables, tomatoes and pumpkin 48

Deficiency of Vitamin A • Children do not grow properly • Difficult for the body to fight infection • Develops night blindness which is a condition of not being able to see in dim light and will eventually lead to blindness 49

Excess of Vitamin A • Too much vitamin A is poisonous to the body • May lead to liver and bone damage 50

VITAMIN D 51

Functions of Vitamin D • Vitamin D is essential for the formation of strong and healthy bones and teeth especially during childhood and adolescence • Helps control the amount of calcium absorbed from food 52

Sources of Vitamin D • The skin can make vitamin D after exposure to sunlight in about 10 to 15 minutes and stored in the liver • Foods that provide vitamin D: – oily fish, like tuna, mackerel and salmon – foods fortified with vitamin D, e. g. margarine – liver – cheese – egg yolks 53

Deficiencies of Vitamin D • If there is a shortage of vitamin D, the calcium cannot be absorbed, and the teeth and bones can become weak • This can lead to rickets in children where the bones become soft and bend out of shape 54

Rickets Shortage of vitamin D Poor calcium absorption from food Bones become soft and bend out of shape 55

VITAMIN E 56

Functions of Vitamin E • Vitamin E is an antioxidant which helps stop substances that get into the body from the air, water and elsewhere from damaging it • Needed to make sure that the cell walls in the body stay healthy • It is thought to reduce the risk of people developing some types of cancers and heart disease 57

Sources of Vitamin E • Foods that provide vitamin E: – vegetable oils, such as wheat germ, sunflower, safflower, corn and soybean oils – nuts, such as almonds, peanuts and hazelnuts – seeds, such as sunflower seeds – vegetables, such as spinach and broccoli – fruits, such as avocado 58

Deficiency of Vitamin E • Deficiency is very rare, intake is normally enough in a balanced diet 59

VITAMIN K 60

Functions of Vitamin K • Helps the blood clot – the blood will thicken and “clot” at the place where the injury takes place in order to allow it to be repaired and to stop the body from losing too much blood 61

Sources of Vitamin K • Foods that provide vitamin K: – vegetables, especially green, leafy vegetables – cheese – liver, bacon – coffee, green tea – Chinese herbal medicine • It is also made by bacteria that live naturally in the intestines 62

Deficiency of Vitamin K • Deficiency is rare, intake is normally enough in a balanced diet 63

References • British Nutrition Foundation (2016). Nutrition Requirements. Retrieved from https: //www. nutrition. org. uk/attachments/article/261/Nutrition% 20 Requirements_Revised%20 Oct%202017. pdf • Dietitians of Canada (2014). Food Sources of Folate. Retrieved from http: //www. unlockfood. ca/en/Articles/Vitamins-and. Minerals/Facts-about-Folate. aspx • Insel, P. M. , Ross, D. , Mc. Mahon, K. , & Bernstein, M. (2019). Discovering nutrition. Burlington, MA: Jones & Bartlett Learning. • Otten, J. J. , Hellwig, J. P. , & Meyers, L. D. (2006). Dietary reference intakes: The essential guide to nutrient requirements. Washington, D. C. : National Academies Press. 64