From DT Online


Vitamin Groups Vitamins are needed by the body in small amounts, The body cannot make vitamins and so they must be supplied by food. Two Groups of vitamins exist classified according to the substance in which they dissolve.
  • Fat Soluble - Vitamins A,D,E and K
  • Water Soluble - Vitamin B complex and Vitamin C dissolve in water.

Bacteria in the intestine can produce some of the vitamins in the B complex but not enough to meet the body's needs.

Vitamin A Vitamin A is necessary for growth and the maintenance of healthy skin. It prevents infection and dryness of mucous membranes in the throat, bronchial, digestive and excretory systems. It is also needed to make 'visual purple', helping the eye to see in dim light.

Good food sources include oily fish, dairy foods and margarine. Vitamin D can also be supplied by fruit and vegetables.

Vitamin B complex
  • Vitamin B1 is needed for energy release, normal body growth and maintenance of health and nervous system.
  • Vitamin B2 is needed for growth and the release of energy from food. Vitamin B2 can be supplied by kidneys, heart and pork.
  • Vitamin B3 is also needed for growth and the release of energy from food.
  • Vitamin B12 is needed in the metabolism of amino acids (proteins).

Good sources of Vitamin B include wholegrain cereals, yeast, yeast extract, milk and eggs.

Vitamin C Vitamin C helps bind body cells together, helps the body absorb iron. It helps keep teeth and bones strong, maintains the lining of the digestive system and also helps in production of blood.

Good sources of vitamin C include rosehips and blackcurrants. Other sources include citrus fruits and beansprouts.

Vitamin D Vitamin D is essential for healthy bones and teeth. It promotes the absorption of minerals which prevent soft bones.

Good sources of Vitamin D include liver, fish oil and oily fish. Other sources include egg yolks, dairy produce and margarine.

Vitamin E The function of vitamin E remains unclear, and deficiency diseases are virtually unknown as the vitamin is so widely available.

Good sources of vitamin E are abundant and include lettuce, peanuts, seeds, wheatgerm oil, milk and egg yolk.


Minerals are elements needed by the body other than carbon, hydrogen and oxygen.
  • Calcium (Ca) is needed in relatively large amounts and its absorption is controlled by vitamin D. It Combines with phosphorus to make calcium phosphate.
    • Function:
  1. to provide hardness and strength to bones and teeth.
  2. needed for the blood clotting process.
  3. needed for muscle and nerve functioning.
  4. needed for maintenance of healthy bones and teeth.

Good supply is found in milk, cheese, eggs, white bread (added by law), bones of fish. Other supplies found in:

  1. green vegetables, as cellulose, which is indigestible and is therefore not available to the body.
  2. whole grain cereals, yet it combines with phytic acid and is unavailable to the body.
  • Iron, combined with vitamin C is used for energy and cell maintenance. Good sources include liver, kidney and cocoa. Other sources include curry powder and treacle.
  • Sodium, chloride and potassium keep the concentration of body fluids level. Chloride is also needed to produce the natural stomach acids. Sodium chloride is common salt. These minerals are found in yeast extract, fish, cheese and bacon.


Carbohydrates are produced mainly by plants during photosynthesis. They fall into two categories:
  • sugar
  • starch and cellulose

Carbohydrates contain the 3 elements: carbon, oxygen and hydrogen.

Carbohydrates are an important energy source, acting as a protein sparer. Allowing protein to be used for body growth and repair and maintenance. Sugar is, however, a source of empty energy providing no other nutrients and it is better to gain energy from other foods. Excess carbohydrate is converted into fat and stored under the skin - snack foods in the diet may cause obesity if eaten in large amounts. Starch is a good energy source, containing other nutrients and dietary fibre. It also serves to prevent over eating - starchy foods are bulky and therefore filling.

  • Sugar is found in jam, honey, treacle and syrup. (N.B. Sugar causes tooth decay and in excess it can lead to obesity).
  • Valuable sources of starch include bread, flour, potatoes and pasta.


Protein must be obtained from foods as the body cannot make the essential amino acids.
  • Animal protein - with a high biological value, containing all the essential amino acids. Also called COMPLETE PROTEINS.
  • Plant protein - said to be of low biological value, lacking one or more of the essential amino acids.
  • T.V.P.- textured vegetable protein is a meat substitute and extender.

The molecules of protein join to form amino acids which are linked together in a chain.

There are at least 22 different amino acids.


Fat is available as hard or soft fat. Animal fats are normally hard. Vegetable fats or plant fats are usually soft and sold in the form of oil. Fats are composed of the elements carbon, hydrogen and oxygen which combine to form fat molecules. Fatty acids are both saturated (predominantly solid at room temperature) and unsaturated (existing in oils).
  • Function:
    • fats provide a convenient and concentrated source of energy.
    • to provide the body with other essential nutrients, some fats contain the vitamins A,D,E and K.
    • under the skin fat provides insulation.
    • to prevent damage to vital organs fat is present around the organs.
    • to provide long term energy.
    • fat serves to create a feeling of fullness preventing over eating, fat digestion is slow.
    • fat aids food preparation, making certain foods more palatable.

N.B. fats in food serve many functions but too much fat in the diet can increase the risk of heart disease.

  • Animal sources - lard, suet, milk produce, egg yolk, fish, liver oils, oily fish.
  • Plant sources - sunflower oil, nuts, kernals, fruit. e.g. avocado.


Dietry Fibre comprises the indigestible parts of food which remain in the large intestine after digestion. Fibre makes up the plant cell walls of food. Tthe fibrous wrapping surrounds the nutrients contained in the food.
  • Functions:
    • to absorb water and bind other food residues to itself - ensuring soft and bulky faeces (solid body waste processed in large intestine) and allows the faeces to pass easily out of the body in the minimum time preventing: a) constipation - which causes discomfort and a feeling of ill health. b) diverticular disease. c) varicose veins and hernias.
    • dietary fibre serves to slow down the absorption of sugars which is an important function for diabetics.
    • serves to add bulk, it is therefore helpful to slimmers.

Sources of dietry fibre include bran in breakfast cereals, wholemeal flour, wholegrain cereals, root vegetables, peas, beans and dried fruit.