Water Soluble Vitamins Definition and Examples

What are Vitamins?

Vitamins are micronutrients. They are natural substances found in foods that do different jobs in the body. Each vitamin is given a letter to identify it (e.g. vitamin C), but they also have chemical names. It is useful to know these because they are often used on food labels and in books and other sources of information.

Water-soluble vitamins

These vitamins dissolve in water. They include the vitamin B group (there is more than one vitamin B) and vitamin C.

Vitamin B group

Scientists originally thought there was only one vitamin in this group, but then discovered that there were several more that had similar jobs in the body. So they were all grouped together and are sometimes known as the ‘vitamin B complex’.

This section tells you:

  • the chemical names of each vitamin in the vitamin B complex
  • why the body needs these vitamins
  • the foods which give us these vitamins
  • what happens if we do not have enough (a deficiency) of these vitamins
  • what happens to these vitamins when foods are processed and cooked.

Vitamin B1 (Thiamin)

Function (its job in the body):

  • It helps to release enery from carbohydrates
  • It helps the body to grow
  • It helps the nerves to work properly.

Sources (the foods it is found in):

  • It is not stored in the body, so a supply is needed every day
  • Cereals such as wheat and rice (especially whole grain) and cereal products, wheatgerm (from the wheat seeds)
  • Yeast and yeast extracts (Marmite)
  • All types of meat (especially pork, bacon, ham, liver, kidney, heart)
  • Eggs, fish roe (eggs)
  • Milk and dairy foods
  • Seeds, nuts, beans.

Deficiency (what happens if we do not have enough):

The body will develop a disease called beri-beri. There are two types:

  • Wet beri beri
  • Dry beri beri

Beri beri often causes muscle wastage. It is usually only seen in communities where there is little to eat and where they eat a lot of polished white rice (where the outside layers of the rice have been removed) and not much else. It is also sometimes seen in people who are addicted to alcohol.

Effects of processing and cooking:

  • Easily detroyed by heat when cooking
  • Easily dissolves in water.

Vitamin B2 (Riboflavin)

Function (its job in the body): helps to release energy from carbohydrates, fats and proteins.

Sources (the foods it is found in): the same as thiamin.

Deficiency (what happens if we do not have enough): low intakes can lead to dryness and cracking of the skin around the mouth and nose, and a swollen tongue.

Effects of processing and cooking: damaged by exposure to sunlight, such as milk left in a glass bottle on a doorstep after being delivered (although most milk is now sold in plastic containers and bought from shops).

Vitamin B3 (Niacin)

Function (its job in the body):

  • It helps to release energy from food
  • It can be used to lower the levels of fat in the blood.

Sources (the foods it is found in):

  • The same as thiamin and riboflavin
  • Also, niacin can be made in the body from an amino acid (see page 39) called tryptophan.

Deficiency (what happens if we do not have enough):

  • The body will develop a disease called pellagra (the word comes from two Italian words: ‘pelle’ meaning skins and ‘agro’ meaning sour). The symptoms of pellagra are known as the ‘three Ds’:
  • Diarrhoea
  • Dermatitis (roughened, sore skin)
  • Dementia (confusion, memory loss, unable to speak properly).

Vitamin B5 (Pantothenic acid)

Function (its job in the body): helps to release energy from food.

Sources (the foods it is found in): a wide range of foods.

Deficiency (what happens if we do not have enough): A deficiency is rare.

Vitamin B6 (Pyridoxine)

Function (its job in the body): helps the body to use protein, fat and carbohydrate for different jobs.

Sources (the foods it is found in): found in small amounts in a wide range of foods.

Deficiency (what happens if we do not have enough): can lead to headaches, general aching and weakness, anaemia (a problem with the cells in the blood) and skin problems.

Effects of processing and cooking: can be destroyed during cooking.

Vitamin B9 (Folate)

Folate is the natural form of the vitamin. There is also a man-made form called folic acid.

Function (its job in the body):

  • It helps the body to use protein
  • It has a very important job to make a special material called DNA in the body cells, when they divide to produce more cells, especially the cells in the bone marrow (which produce red blood cells) and the cells that line the digestive system.

Sources (the foods it is found in):

  • Green and leafy vegetables – spinach and green cabbage
  • Liver
  • Potatoes
  • Fruits – oranges and berries
  • Asparagus, okra
  • Beans and sees
  • Wholegrain cereals
  • Nuts

Folic acid is also added to breakfast cereals.

Deficiency (what happens if we do not have enough):

  • A deficiency can lead to cells in the digestive system not dividing properly, so other nutrients are not absorbed. This can lead to loss of appetite, nausea (feeling sick), diarrhoea and soreness in the mouth
  • A deficiency can also lead to cells in the bone marrow not dividing properly which will lead to the red blood cells becoming very large and not being able to deliver enough oxygen around the body. This is called megaloblastic anaemia (‘mega’ meaning big, ‘blastic’ meaning cells, ‘anaemia’ meaning not enough active red blood cells in the blood)
  • In the very first stages of pregnancy large numbers of cells develop and divide to produce all the different parts of the body. Pregnant women need about five times more folate than normal. One of the vital stages of pregnancy is the development of the spinal cord and backbone. If a woman does not have enough folate, her baby may develop a deformity in the spine called spina bifida. It is important that women have enough folate in their diet before they conceive a baby and in the first few months of pregnancy to avoid this. Folic acid supplements are given to make sure that such women have enough in their diet.

Effects of processing and cooking:

  • Folate is less sensitive to heat than other B vitamins but it will be destroyed if food is reheated or kept hot for a while
  • Folic acid is more stable when cooking and in the digestive system, so is more likely to be absorbed into the body

Vitamin B12 (Cobalamin)

Function (its job in the body):

  • It is needed to form a protective coating around nerve cells to make them work properly
  • It is important for the correct production of new cells.

Sources (the foods it is found in):

  • It can be stored in the liver
  • It is only found in foods from animals (meat, milk, dairy products and liver), so vegans (people who do not eat any animal products) need to make sure they take a supplement.

Deficiency (what happens if we do not have enough):

  • A deficiency will prevent the nerves from working properly and will lead to paralysis, memory loss and confusion
  • A type of anaemia called pernicious anaemia can occur in people who have had certain medical conditions that stop the vitamin B12 from being absorbed.

Vitamin C

This section tells you:

  • the chemical name for vitamin C
  • why the body needs vitamin C
  • the foods which give us vitamin C
  • what happens if we do not have enough (a deficiency) vitamin C
  • what happens to vitamin C when foods are processed and cooked
  • how to conserve vitamin C in foods when you are preparing and cooking
    them.

Vitamin C (Ascorbic acid)

Function (its job in the body):

  • It is needed to enable the body to absorb iron from the food we eat
  • It is needed for the production of a protein in the body called collagen
  • Collagen is the protein in connective tissue which is the substance that binds the body cells together
  • It is also an antioxidant. Antioxidants help to protect the body from polluting chemicals that get into the body – from the air, water or in food.

Sources (the foods it is found in):

  • Fruits and vegetables, especially blackcurrants, citrus fruits, green peppers, kiwi fruit, green, leafy vegetables (not lettuce), Brussels sprouts, broccoli, bean sprouts, peas, potatoes (we eat a lot of potatoes so they give us an important amount)
  • There is a small amount in liver and fresh milk.

Deficiency (what happens if we do not have enough):

A deficiency is rare but is occasionally seen in older adults and some children who have very little fresh fruit and vegetables in their diet

The body is able to store some vitamin C, but we cannot make it in our bodies and so need some every day in our diet

If someone has a slight deficiency, anaemia develops because not enough iron is absorbed. The symptoms are tiredness and weakness

A severe deficiency leads to the disease scurvy which has the following symptoms:

  • tiredness and weakness
  • bleeding gums
  • anaemia
  • poor wound healing and damage to bone and other tissues.

Effects of processing and cooking:

  • Vitamin C is destroyed by heat and exposure to oxygen
  • It dissolves very easily in water (water-soluble).

To prevent this, it is important to prepare and cook fruits and vegetables in the following way:

  • Buy them as fresh as possible (so they have the most vitamin C)
  • Prepare them at the last minute before you need them to avoid long exposure to the air
  • Cook them in as little water as possible (steaming is a better method), for as short a time as possible and serve them straightaway – do not keep them hot for a while before serving
  • Use the water they were cooked in for making gravy or soup.

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