1. Micronutrients
(vitamins and minerals)
Vitamins

2. Vitamins Vitamins are needed in very small amounts in the diet.
This is why vitamins are called ‘micronutrients’.
Measured in micrograms (mcg) or milligrams (mg)
1milligram (mg) = 1000 micrograms (mcg)
Vitamins are divided into two groups:
Fat soluble vitamins.
Water soluble vitamins.
The fat soluble vitamins are: The water soluble vitamins are:
Vitamin A B group vitamins (you will study 5 of these)
Vitamin D Vitamin C
Vitamin E
Vitamin K

3. Fat soluble vitamins
Vitamin A Vitamin D Vitamin E Vitamin K

4. Vitamin A There are two types of vitamin A:
Retinol from animal sources – eggs, oily fish, liver, whole milk, butter and cheese
Beta carotene from vegetable sources – carrots, sweet potatoes, red peppers, mangoes and apricots
FUNCTION
Growth and development
Healthy skin
Good vision in dim light
Protection: it is an antioxidant vitamin

5. Vitamin A
SOURCES

6. Vitamin A DEFICIENCY and EXCESS
A deficiency of vitamin A may lead to night blindness. This means you cannot see in dim light.
Excess of vitamin A can cause poisoning. It can be very harmful to unborn babies if their mother consumes too much vitamin A. Liver is very high in vitamin A – that is why pregnant women should avoid eating liver.
DRV
Age
Male
Female
4 years
500mcg
10 years
14 years
600mcg
Adults
700mcg
Older adults (50 +)

7. Vitamin D FUNCTION SOURCES
Vitamin D is provided by foods as well as the action of sunlight on the skin.
Humans make 90 percent of our vitamin D naturally from sunlight exposure to our skin. Ten to 15 minutes of sunshine three times weekly is enough to produce the body's requirement of vitamin D. The sun needs to shine on the skin of your face, arms, back, or legs (without sunscreen). People who do not live in sunny places may not make enough vitamin D. Skin that is exposed to sunshine indoors through a window will not produce vitamin D. Cloudy days, shade, and having dark-colored skin also cut down on the amount of vitamin D the skin makes.
FUNCTION
Essential for developing and maintaining strong bones and teeth
Healing broken bones
Preventing bone diseases such as rickets and osteoporosis
Helping the body absorb calcium and phosphorus
SOURCES
Milk, butter, liver, oily fish and egg yolk
Fortified breakfast cereals with added Vit D
Fortified fats i.e. fat and margarine spreads
Action of sunlight on human skin

8. Vitamin D EXCESS and DEFICIENCY DRV
Not enough vitamin D can result in:
Rickets in babies and toddlers – this means the bones are soft and they can bend and bow
Osteoporosis in adults – this means bones become weak and fragile, making them more likely to break
Groups at risk of deficiency: pregnant and breastfeeding women, babies and young children under 5, people who are not exposed to much sun such as people who cover up their skin when outdoors or those who are inside their home for long periods
Too much Vit D is stored in the body and unlikely to cause any problems
DRV
Everyone over 4 years old should consume 10micrograms of Vit D each day

9. Vitamin E FUNCTION Vitamin E is needed for:
Protecting the body – it is an antioxidant (a vitamin that helps protect healthy cells from the damage caused by the normal aging process as well as from certain types of cancer)
The formation of red blood cells
SOURCES
Sunflower oil
Olive oil
Soya
Cereals and cereal products
Nuts
Seeds
Egg yolk

10. Vitamin E DEFICIENCY and EXCESS A deficiency of vitamin E is rare.
Excess vitamin E causes a loss of appetite.
DRV
Men = 4 milligrams per day
Women = 3 milligrams per day

11. Functions of vitamin K FUNCTION Make the blood clot
Maintain bone health
SOURCES
Green leafy vegetables i.e. green beans and peas, broccoli, spinach
Vegetable oils
Cereals
DEFICIENCY and EXCESS
Deficiency is rare as vitamin K is made in the body:
Signs of deficiency are easy bruising and bleeding and the blood taking longer to clot.
Babies are often given a dose of vitamin K soon after birth to prevent a rare blood disorder.
Excess of vitamin K: There is not enough evidence on the effects of high doses of vitamin K.
DRV
Teenagers = 0.045mg per day
Males = 0.075mg per day
Females = 0.065mg per day

12. Water soluble vitamins
Vitamin B1 - Thiamin Vitamin B2 - Riboflavin Vitamin B3 - Niacin Vitamin B12 Folic Acid Vitamin C – ascorbic acid

13. Vitamin B1 (Thiamin) Functions: - release energy from food
- helps the nervous system work
Food sources: liver, milk, cheese, bread, eggs, peas, nuts, potatoes, fortified breakfast cereals, added to flour
Effect of excess: rare
Effect of deficiency: disease called Beri Beri, a muscle wasting disease only seen in countries with food shortages.

14. Vitamin B2 (riboflavin)
Functions: to
- Helps body to release energy from food you eat
- Keeps the skin, eyes and mucous membranes healthy
Food sources: found inside every animal and vegetable cell
Chicken, eggs, milk, yoghurt, fish, leafy vegetables, rice,
bread, breakfast cereals, almonds, mushrooms
Effect of excess: none reported
Effect of deficiency: rare, but may cause skin problems such as dry and cracked lips and poor growth in children

15. Vitamin B3 (niacin)
Functions: to release energy from foods, keeps the skin and nervous system healthy.
Food sources: meat, fish, flour, eggs, dairy products, pulses, dried apricots and peaches
Effect of excess: can cause liver damage if large amounts are eaten.
Effect of deficiency: a disease called pellagra – symptoms are the three ‘d’s: dermatitis, dementia and diarrhoea.

16. Folic acid
Functions:
- Reduce nervous system birth defects in unborn babies
- Works with Vit B12 to form healthy red blood cells
Food sources: fortified breakfast cereals, broccoli, Brussels sprouts, chickpeas, liver, asparagus, peas, oranges, avocado
Effect of excess: no harmful side effects have been reported
Effect of deficiency: to prevent spina bifida in unborn babies. Spina Bifida means ‘split spine’ and is defect in the backbone that can occur in unborn babies if not enough folic acid was eaten by the mother during pregnancy.

17. Vitamin B12 (Cobalbimin)
Functions:
- Maintains nerve cells
- Makes red blood cells
- Releases energy from the foods you eat
- Processes folic acid
Food sources: meat, eggs, milk, salmon, cod, fortified
breakfast cereals
Effect of excess: no known side effects have been reported.
Effect of deficiency: a condition called pernicious anaemia – most likely in vegans as they do not eat animal products. Tingling and numbness in the hands and feet and loss of memory.

18. Vitamin C (Ascorbic acid)
Functions:
- Makes and maintain healthy connective tissue
- Helps wounds to heal and repairs body tissue
- Helps you to absorb iron from the intestines,
- Is an antioxidant vitamin, so it protects the body
Food sources: citrus fruits (oranges, lemons, limes, grapefruit), blackcurrants, broccoli, Brussels sprouts, potatoes, red and green peppers, strawberries, tomatoes, kiwi, guava
Effect of excess: can cause stomach pain and diarrhoea.
Effect of deficiency: a disease called scurvy, which causes swollen gums, joint pains and wounds failing to heal.

19. The antioxidant vitamins A, C and E
The antioxidant vitamins are: Vit A, C and E and are found in foods that contain these vitamins
Antioxidants help to protect healthy cells from the damage caused by free radicals.
Your body functions and lifestyle habits produce free radicals that can attack healthy cells.
When free radicals are found in large amounts in the body the healthy cells are weakened and are more vulnerable to heart disease and some cancers.
There are large amounts of antioxidants in in fruits, vegetables, nuts and whole grains and smaller amounts in meats, chicken and fish

20. DRV See page 125 in text book Vit B1
The amount of Vit B1 needed is linked to the amount of energy the body needs.
People who require more Vit B1 are:
Pregnant and breastfeeding women, because they are using more enenrgy to carry a baby and produce breast milk
Athletes, because they use up energy during training
Young children and teenagers, because their rapid growth requires more energy
Folic acid
Taking folic acid supplements may prevent the development of spina bifida in pregnancy. Pregnant women or those thinking of having a baby should take at least 300 micrograms of folic acid each day

21. Effect of preparation and cooking on nutritional value
Water soluble vitamins in the Vit B group and Vit C are affected by food preparation and cooking.
They are very unstable –
they dissolve in water and
can be destroyed by contact with sunlight, air and heat and
are affected by enzymes (enzymes are chemicals found inside plant cells that control the ripening of process but they will destroy vitamins)

22. Methods of reducing the loss of water soluble vitamins when preparing and cooking food
Buy fruit and vegetables in good condition Avoid buying bruised or damaged fruit and vegetables. Broken plant cells release enzymes which will start to destroy vitamins
Choose ripe fruit and vegetables Choose just-ripened fruit and vegetables as they contain the most vitamins. Ideally fruit and vegetables should be harvested ripe and eaten shortly afterwards. Unripe or over-ripe products may have a lower vitamin content
Store in cool, dark places Most fruit and vegetables should be stored in a refrigerator (fridge). Enzymes are active a room temperature. The cool temperature of a refrigerator will slow down their activity. Sunlight destroys most vitamins too.
Use shortly after buying Ripening will continue after buying, so use fruit and vegetables up quickly. Pre- packed bags of salad have a modified atmosphere which will slow down the ripening process, but once open the salad will deteriorate quickly and the vitamin loss will be rapid
Minimise preparation
Blanch vegetables

23. 7. Avoid soaking in water 8. Eat fruit and vegetables raw 9
7. Avoid soaking in water 8. Eat fruit and vegetables raw 9. Cook and eat fruit and vegetables in their skin 10. Use a small amount of water when cooking fruit and vegetables 11. Place vegetables in boiling water and cook quickly When vegetables are put in cold water and brought to the boil slowly, the enzymes can destroy the vitamins before the heat from the water destroy the enzymes. Always cook fruit and vegetables for the minimum amount of time required. Use a tightly fitting lid to speed up the cooking process. 12. Use the cooking water Water soluble vitamins will leach into the cooking water during boiling. Use the cooking water to make gravies, sauces and soups to ensure that the vitamins are eaten 13. Serve immediately The longer vegetables are kept warm, the greater the water soluble vitamin loss will be. Avoid reheating as this will reduce the vitamin content even more.

24. Effect of heat, air, sunlight and water on nutritional value
Vitamins
Heat
Air
Sunlight
Water
Vitamin A
Vitamin D
Vitamin E
Vitamin C
Thiamin
Riboflavin (B2)
Folic acid
Vitamin B12
Niacin (B3)
Vitamin K