- Vitamin A
Functions
Maintains healthy vision, skin, teeth and bones as well as many important mucus membranes such as those found in the throat, nose, lungs and intestines. Important for the growth of children.
Deficiency/Excess Problems
Deficiency can cause eye, skin and hair problems and an increased susceptibility to infections. Excessive amounts can be toxic and should be avoided by pregnant women.
Sources
Liver, Kidneys, Fish liver oil, eggs, dairy foods, butter and margarine. Vitamin A if fat soluble so reduced fat dairy products contain less vitamin A than full fat varieties.
- Beta Carotene
Functions
A form of vitamin A converted into retinol the intestines. It is a powerful antioxidant vitamin.
Deficiency/Excess Problems
Deficiency can lead to an increased susceptibility to infections. Large doses of purified beta carotne supplements have been known to turn the skin an orange colour.
Sources
Fruit and Vegetables, particularly yellow, green, orange and red varieties such as carrots, tomatoes, spinach, watercress, broccoli, peppers and apricots.
- Vitamin B Group
Functions
These vitamins work together enabling energy to be released from the food we eat. They are also vital for the production of antibodies, red blood cells, healthy skin and muscle tissue.
Deficiency/Excess Problems
Deficiency can lead to anaemia, fatigue, skin problems and depression. Heavy drinkers, smokers, women on contraceptive pills and vegans may need extra vitamin B.
Sources
Liver, kidneys, poultry, fish, yeast. Wholegrain breads, cereals, seeds, nuts, legumes, eggs, mild cheese, yoghurt and leafy green vegetables.
- Vitamin C
Functions
Protects against infection and is required for the production of collagen and connective body tissue. Aids absorption of iron from non-animal sources and helps maintain a healthy body.
Deficiency/Excess Problems
Deficiency can increase susceptibility to infection, weakness, poor wound healing and loss of appetite. Smokers and heavy drinkers may benefit from vitamin C supplements.
Sources
Fruit and vegetables – especially citrus fruits, blackcurrants, strawberries and kiwi fruit. Raw cabbage, broccoli, peas and potatoes also provide a valuable source.
- Vitamin D
Functions
The ‘sunshine’ vitamin made under the skin when exposed to sunlight. Essential for the proper use of calcium and phosphorus, which are needed for the maintenance of healthy bones.
Deficiency/Excess Problems
Extreme deficiency can lead to bone and joint disorders. However, most adults do not need dietary vitamin D supplements, except some elderly people, pregnant woman or young children.
Sources
Few foods actually contain vitamin D. Those that do not include cod liver oil, kippers, mackerel, canned salmon, eggs and milk. Some margarines are fortified with vitamins A and D.
- Vitamin E
Functions
An antioxidant vitamin that is essential for maintenance of cell membranes.
Deficiency/Excess Problems
Deficiency is very rare although people with a high intake of polyunsaturates may need more vitamin E to sustain normal cell growth.
Sources
Wheatgerm, nuts (particularly peanuts) vegetable oils, eggs, leafy green vegetables and wholemeal bread.
- Calcium
Function
Development and maintenance of healthy bones and teeth and important in the regulation of the heartbeat.
Deficiency/Excess Problems
Deficiency may cause brittle bones (osteoporosis), rickets and muscle problems. Breastfeeding women have an increased need for calcium.
Sources
Dairy Products such as milk, cheese and yoghurt as well as canned fish, leafy green vegetables, nuts and beans. Reduced fat dairy products contain the same amount of calcium as full fat varieties.
- Iron
Functions
Essential for the production of red blood cells that carry oxygen around the body. It also helps the body to fight infection.
Deficiency/Excess Problems
Deficiency can cause anaemia (a lack of red call production) which causes dizziness, fatigue and lack of stamina. Some pregnant women may be advised to take supplements.
Sources
Meat, chicken, fish (especially pilchards and sardines), liver, kidney, eggs, dried apricots, spinach and other leafy vegetables and fortified breakfast cereals.
- Potassium
Functions
Maintains nerves, cells and muscle tissue. Together with Sodium, potassium also helps to regulate water balance and blood pressure.
Deficiency/Excess Problems
Deficiency may lead to vomiting and diarrhoea, muscle weakness and loss of appetite. However, excessively high intakes can sometimes cause dangerous toxic effects.
Sources
Fruit and Vegetables, in particular bananas, apples, carrots, broccoli, dates and oranges. Wheat grain cereals, wheatbran, fish, meat and poultry are also good sources.
- Sodium
Functions
Essential for muscle and nerve activity. Works with potassium to control the body’s water balance and blood pressure.
Deficiency /Excess Problems
Deficiency may arise from dehydration but is rare in Western countries. Excessive sodium can lead to a sustained rise in blood pressure and can also increase the risk of heart disease
Sources
Foods in their natural state do not generally have high sodium content. However it is added to many manufactured foods such as bacon, smoked fish, cereals, yeast extract and bread.
- Zinc
Functions
Needed for normal growth and development of reproductive organs, teeth, bones and the body’s defence system.
Deficiency /Excess Problems
Deficiency can sometimes lead to a lack of physical and sexual development, poor wound healing and a loss of appetite.
Sources
Seafood, red meat, offal, dairy products, eggs, some green vegetables and cereals.