Also known as retinol, vitamin A can be obtained direct from the diet, or can be made in the body from betacarotene - another naturally occurring substance found in our diet. It is needed for healthy hair and skin, and to help us see in dim light.
Sources
Vitamin A is fat-soluble and can be stored in the body. It is found in liver, fish oils, eggs and dairy products. Its precursor betacarotene is obtained from dark green, yellow or orange fruits and vegetables such as spinach, sweet potatoes, mangoes, carrots and peppers. Many margarines and fat spreads have vitamin A added to them.
The recommended daily amount for vitamin A is 800 micrograms; six units of betacarotene is equivalent to one unit of vitamin A.
Vitamin A can be toxic if high doses are taken over a period of time, and have been associated with possible damage to unborn babies. Liver and liver products (which contain high levels of vitamin A) or vitamin A supplements are therefore not recommended for pregnant women.
Also known as thiamine, vitamin B1 is needed for the release of energy from carbohydrates as part of normal body functioning. Deficiency is rarely seen in the UK; usually only in those who consume large amounts of alcohol on a regular basis, as this increases the need for thiamine.
Sources
Thiamine is widely distributed in both animal and vegetable foods. Good sources include milk, offal, pork, eggs, vegetables, fruit and wholegrain cereal products. Many breakfast cereals are fortified with vitamin B1 and so are useful sources. By law, thiamine must be added to most flour (except wholemeal).
The recommended daily amount for vitamin B1 is 1.4mg for adults and children over the age of 5 years. There is no evidence of harm at high doses, as vitamin B1 is water-soluble and excess intakes are excreted.
Also known as riboflavin, vitamin B2 is needed for the release of energy from protein, fat and carbohydrates as part of normal body functioning.
Sources
Riboflavin is widely distributed in foods, especially those of animal origin. In the UK about 40% of the average intake is obtained from milk and dairy products. As riboflavin is destroyed by light, sources of this vitamin (such as milk) should be stored in dim light or dark conditions, eg covered containers, cupboards, fridge. Many breakfast cereals are fortified with vitamin B2 and so are useful sources. Other sources are wholegrain cereal products, liver, kidney and eggs.
The recommended daily amount for vitamin B2 is 1.6mg for adults and children over the age of 5 years. No toxic effects have been reported as vitamin B2 is water-soluble and is therefore excreted.
Also known as pyridoxine, vitamin B6 is needed for the development of body tissue, healthy blood and the metabolism of protein.
Sources
Fish, poultry, lean meats, bananas, prunes, dried beans, wholegrain cereals and some vegetables.
The recommended daily amount for vitamin B6 is 2mg for adults and children over the age of 5 years. Deficiency is rare. Long-term use of high dose vitamin B6 supplements may cause nerve damage in hands and feet.
Also known as cobalamin, vitamin B12 is needed for the development of healthy cells, normal functioning of the nervous system and the metabolism of protein and fat.
Sources
Meat, yeast (and its products such as Marmite), seafood and milk products.
The recommended daily amount for vitamin B12 is 1mg for adults and children over the age of 5 years. No toxic effects have been reported.
As vitamin B12 is found only in animal products and yeast, vegetarians and vegans who do not eat these foods may need to take a supplement.
Biotin is needed for the metabolism of protein, fats and carbohydrates. Only very small amounts are needed, and some may be made by bacteria in the large intestine.
Sources
Good sources include offal and egg yolk. Smaller amounts are obtained from cereals/grain products, fish, fruit and vegetables.
The recommended daily amount for biotin is 0.15mg for adults and children over the age of 5 years. No toxic effects have been reported and deficiency is extremely rare in the UK.
